Journal of Surgical Oncology 2014;110:383–392
REVIEW Temporal Bone Carcinoma. Current Diagnostic, Therapeutic, and Prognostic Concepts M. LIONELLO, MD,1* P. STRITONI, MD,2,3 M.C. FACCIOLO, MD,1 A. STAFFIERI, MD,1 A. MARTINI, MD,2 A. MAZZONI, MD,2 E. ZANOLETTI, MD,2 AND G. MARIONI, MD1 1
Department of Neurosciences, Otolaryngology Section, University of Padova, Padova, Italy 2 Department of Neurosciences, Otosurgery Unit, Padova Hospital, Padova, Italy 3 Visiting Doctor at Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
Temporal bone carcinoma is an uncommon aggressive malignancy. Its low incidence and the absence of a globally accepted staging system still make it difficult to compare different centers’ approaches and results. In this review of the main available studies dealing with temporal bone carcinoma since 1995, we consider its rational preoperative staging and assessment, compare the effectiveness of different treatments by tumor stage, and outline the main actuarial prognostic factors.
J. Surg. Oncol. 2014;110:383–392. ß 2014 Wiley Periodicals, Inc.
KEY WORDS: temporal bone; carcinoma; diagnosis; treatment; prognosis; biomarkers
EPIDEMIOLOGY AND PATHOGENESIS With an estimated 633,000 new cases in 2008, head and neck squamous cell carcinoma ranked as the 7th most common cancer worldwide when the global incidence and related mortality of malignancies was estimated for 182 countries by the International Agency for Research on Cancer as part of the GLOBOCAN scheme [1]. More recently, the American Cancer Society estimated that a total 1,660,290 new cases of cancer would occur in the United States in 2013, including 53,640 primary head and neck malignancies (excluding thyroid cancers) [2]. Temporal bone cancer accounts for less than 0.2% of all tumors involving the head and neck region [3]. There seem to be significant differences in its geographical distribution around the world: while it reportedly has an incidence of about 0.8–1 per million population per year in Western countries (England, Wales, and USA), carcinoma of the external auditory canal alone has been reported to have an incidence of 2.1 per million population per year in Singapore [4]. The gender distribution varies, but most authors have found a higher incidence in males. Among temporal bone malignancies, squamous cell carcinoma is by far the most common histological pattern [5]. After excluding primary locations outside the temporal bone, primary squamous cell carcinoma accounts for 60–80% of tumors arising in the auditory canal, middle ear, or mastoid cavity [6]. Like most epithelial malignancies, the majority of cancers of the external auditory canal and middle ear occur in the fifth and sixth decades of life [7,8]. A multifactorial etiology has been suggested for temporal bone carcinoma. For tumors arising from the external auditory canal (EAC) or pinna, exposure to ionizing radiation seems to be the most important risk factor (especially in fair‐skinned people), while a genetic susceptibility has been hypothesized for people not exposed to such radiation [9]. Head and neck radiation therapy has been considered a predisposing factor, especially in Asian people, where a higher prevalence of nasopharyngeal carcinomas treated primarily with radiotherapy (RT) was associated with a higher incidence of temporal bone squamous cell carcinomas (TBSCC) [10]. In the literature, a history of chronic suppurative otitis media has been associated with the onset of TBSCC [11], but there is no
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significant evidence to confirm this association [7]. A role has been suggested for chlorinated disinfectants in the etiopathogenesis of middle ear carcinoma [12] and for human papillomavirus in cases of TBSCC associated with inverted papilloma [13,14].
DIAGNOSIS: CLINICAL AND RADIOLOGICAL EVALUATION Despite its superficial position, temporal bone carcinoma is usually diagnosed late because its early signs and symptoms are non‐specific. Most patients initially complain of symptoms that are frequently attributed to inflammatory otological diseases. The most common clinical findings (Table I) consist of aural discharge (24–100%) or bleeding, otalgia (19–81%), and hearing loss (2–75%). Facial nerve paresis or palsy at presentation (7–64%) is considered a sign of advanced disease, as is evidence of an EAC mass. An early diagnosis is crucial for prompt treatment and a good outcome. Although tumors involving the lateral third of the EAC or the pinna might be thought to have a better prognosis, cutaneous carcinomas in the periauricular region, and carcinoma involving the EAC in particular, are reportedly more
Grant sponsor: University of Padova, Padova, Italy; Grant number: 60A07‐ 1341/12. M. Lionello and P. Stritoni contributed equally to the manuscript’s preparation. Conflict of Interest: None. *Correspondence to: Marco Lionello, MD, Department of Neurosciences, Otolaryngology Section, University of Padova, Padova, Italy. Fax: þ39‐049‐ 8213113. E‐mail: [email protected] Received 20 February 2014; Accepted 29 April 2014 DOI 10.1002/jso.23660 Published online 24 June 2014 in Wiley Online Library (wileyonlinelibrary.com).
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TABLE I. Demographics, Signs, and Symptoms at Presentation of TBSCC
References Pensak et al. [15] Manolidis et al. [16] Gal et al. [17] Chee et al. [4] Lim et al. [10] Moody et al. [18] Gillespie et al. [19] Nyrop et al. [20] Isipradit et al. [21] Lavieille et al. [22] Moffat et al. [23] Yin et al. [5] Lobo et al. [24] Chang et al. [25] Cristalli et al. [26] Ito et al. [27] Dean et al. [28] Morris et al. [29] Hosokawa et al. [30] Gidley et al. [31] Zhang et al. [32] Bacciu et al. [33] Lassig et al. [34] Leong et al. [35]
No. of cases
Male patients (%)
Mean age (%)
Otorrhea (%)
Otalgia (%)
Hearing loss (%)
Clinical involvement of VII cranial nerve (%)
46 81 21 14 18 32 15 20 16 30 39 95 19 12 17 16 65 72 15 157 43 45 30 35
54% 51% 90% 64% 55% ND 26% 50% 56% 90% 48% 63% 58% 83% 65% 43% 77% 74% 4% 76% 63% 56% 66% 68%
63 48 63 57 56 68 66 67 57 65 61 64 65 56 73 64 65 63 58 60 53 62 70 66
84% 24% ND 78% 55% 75% 73% 45% 69% 53% 69% 42% 68% 67% ND 94% ND ND ND 21% 70% 73% 33% 100%
74% 55% ND 35% 39% 81% 53% 35% 19% 53% 64% 24% 47% 34% ND 75% ND ND 27% 24% 81% 22% 43% 66%
62% 73% ND 21% ND 62% 33% 40% 37% 36% ND 2% 31% 8% ND 62% ND ND ND 46% 86% 75% ND ND
18% 64% 33% 35% 22% 25% 13% ND 12% 36% 7% 4% 21% ND 52% 18% 60% 20% 0% 38% 18% 17% 40% 46%
ND, no data.
aggressive than those arising in other areas of skin, probably due to multiple embryonic fusion planes facilitating tumor spread [36]. All patients with suspected temporal bone cancer should undergo a complete ENT assessment and micro‐otoscopy with extensive biopsies. Histology is crucial for a rational planning of treatment for temporal bone malignancies. According to current head and neck oncology guidelines, staging has to be done on radiological evidence of local and regional anatomical regions (high‐resolution temporal bone computerized tomography [CT] and contrast‐enhanced magnetic resonance imaging [MRI], neck ultrasonography with or without fine needle aspiration cytology on nodes). Positron emission tomography should be used to rule out distant metastases in advanced cases. Radiological imaging plays a central part in preoperative staging because the temporal bone’s anatomy hinders physical examination. High‐resolution CT is mandatory because it is highly sensitive in detecting early bone erosion, which is often the first sign of the disease spreading locally [19]. In 1990, Arriaga compared CT scans of 13 patients with closely‐correlating intraoperative and pathological evidence of the disease’s pathological extent [37]. High‐resolution CT scanning enables a reliable assessment of any invasion of the wall of the internal carotid artery canal, jugular bulb, and otic capsule [38]. The main limitations of CT imaging consist in the difficulty of distinguishing inflammatory mucosa from neoplastic tissue, particularly where there is no significant bone erosion [18]. Contrast‐ enhanced MRI reveals the tumor’s extent and better differentiates tumor from non‐neoplastic soft tissue [18]. It can identify petrous apex or temporo‐mandibular joint involvement [38], and dura mater invasion or intracranial extension [6]. It has also been demonstrated that contrast‐ enhanced MRI can nearly always detect parotid gland involvement and neck node metastases [19]. Bone CT and contrast‐enhanced MRI can be considered as complementary techniques for the purpose of correct staging. Journal of Surgical Oncology
STAGING No internationally accepted staging system is available for TBSCC (Table II). Several classifications have been proposed, but neither the International Union Against Cancer (UICC) nor the American Joint Committee on Cancer (AJCC) have so far endorsed any of these systems for staging ear and temporal bone tumors [39]. This continues to pose a problem when comparing results reported by different institutions (Fig. 1) and attempting to arrive at globally accepted guidelines on how to approach the disease. Among the many classifications proposed over time, Goodwin and Jessels described a three‐stage system correlated with tumor depth in 1980 [40], followed by Stell and McCormack suggesting a system in which any extratemporal spread was considered as T3 [41]. Clark et al. [42] then proposed differentiating between T3 lesions with a more favorable prognosis (with parotid, temporal‐ mandibular joint, and skin involvement) and those with a worse prognosis (when the dura mater and skull base are involved). The Pittsburgh University group came up with a clinical classification based on preoperative computed tomography and physical examination [37]. In 2000 Moody et al. suggested updating the Pittsburgh staging system to emphasize the importance of clinical facial nerve involvement, based on the assumption that nerve paralysis indicates invasion of the medial wall of the middle ear or mastoid. A clinical presentation with facial paresis or paralysis would thus be staged as T4 [18]. This is currently the most commonly used system for staging temporal bone carcinoma.
TREATMENT: SURGICAL OPTIONS Surgery for Primary Carcinoma (Table III) The treatment of TBSCC is challenging for head and neck surgeons and otologists. Over time many surgical approaches have been proposed with a view to improving the oncological safety of its treatment while minimizing the injury to nearby important neurovascular structures.
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Fig. 1. Distribution of papers available in the English language (at December 2013) on cohorts of patients with temporal bone carcinoma, published since 1995. The Pub‐Med (http://www.pubmed.gov) electronic database was searched. The search terms used were: “temporal bone cancer”, “temporal bone carcinoma”, “temporal bone malignancy”, “ear cancer”, “ear carcinoma”, “ear malignancy.” The “Related articles” option on the Pub‐Med homepage was also considered. Some papers were found in more than one search. The full texts of the publications identified were screened for original data and reference lists were checked for other relevant studies. One of the most debated issues when it comes to finding a rational surgical approach to temporal bone malignancies is the choice between en bloc versus piecemeal tumor removal. The en bloc approach was first mentioned in the 1950s by Campbell [54], and Parsons and Lewis [55], when it was considered technically more difficult but the only solution capable of ensuring radicality. In the light of these authors’ considerations, en bloc temporal bone resection has been classified as
lateral, subtotal or total (LTBR, STBR, and TTBR, respectively) (Fig. 2). The LTBR is an en bloc lateral petrosectomy through a temporal craniotomy: the outer hearing canal is completely removed, including the eardrum and part of the mastoid. The resection could be extended anteriorly to the condyle and the glenoid fossa, posteriorly beyond the sigmoid sinus, inferiorly to the jugular bulb and superiorly to the middle cranial fossa floor. Since the resection remains lateral to the labyrinth,
TABLE II. Available Staging Systems for TBSCC Primary tumor (T) ‐ AJCC staging system Tis Carcinoma in situ T1 Tumor 2 cm in greatest dimension with 2 cm with or without one additional high‐risk feature, or any size with 2 high‐risk features T3 Tumor with invasion of maxilla, mandible, orbit, or temporal bone T4 Tumor with invasion of (axial or appendicular) skeleton or perineural invasion of the cranial base Primary tumor (T) ‐ University of Pittsburgh staging system (Moody’s modified) T1 Tumor limited to the external auditory canal without bone erosion or evidence of soft tissue involvement T2 Tumor with limited external auditory canal bone erosion (not full‐thickness) or limited (6 cm in greatest dimension; or in bilateral or contralateral lymph nodes, none >6 cm in greatest dimension N3 Metastasis > 6 cm Distant metastasis (M) Mx Distant metastasis cannot be assessed M0 No distant metastasis M1 Distant metastasis Overall stage I T1 N0 II T2 N0 III T3 N0; T1 Nþ IV T4 N0; T2‐4 Nþ
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TABLE III. Clinicopathological Characteristics and Reported Treatment Modalities
References
Clinical involvement Surgery on Neck Adjuvant of VII c.n.b No. cT3‐4 No. of pNþ No. of T No. Parotidectomy No. dissection No. RT No. of No. of of cases (%) cases (%) cases (%) of cases (%) of cases (%) of cases (%) cases (%) cases SCCa (%)
Testa et al. [43] 79 Manolidis et al. [16] 81 Gal et al. [17] 21 Pfreundner et al. [44] 27 Chee et al. [4] 14 Hashi et al. [45] 20 Lim et al. [10] 18 Moody et al. [18] 32 Gillespie et al. [19] 15 Lavieille et al. [22] 30 Nakagawa et al. [38] 25 Martinez‐Devesa et al. [39] 27 Moncrieff et al. [46] 42 Moore et al. [47] 35 Bibas et al. [48] 18 Kunst et al. [49] 28 Lobo et al. [24] 19 Madsen et al. [50] 68 Chang et al. [25] 12 Cristalli et al. [26] 17 Prabhu et al. [51] 30 Dean et al. [28] 65 Morris et al. [29] 72 Gidley et al. [31] 157 Hosokawa et al. [30] 15 Bacciu et al. [33] 45 Lassig et al. [34] 30 Leong et al. [35] 35 Marioni et al. [52] 25 Zanoletti et al. [53] 41 Zhang et al. [32] 43
56 32 67 92 100 100 83 100 100 80 100 74 100 57 100 100 100 69 83 100 100 57 54 39 60 100 100 100 100 100 49
10 (13%) 52 (64%) 7 (33%) ND 5 (35%) ND 4 (22%) 8 (25%) 2 (13%) 11 (36%) ND ND ND ND ND ND 4 (21%) ND ND 9 (52%) ND 39 (60%) 13 (20%) 61 (38%) ND 8 (17%) 12 (40%) 16 (46%) ND ND 8 (18%)
45 (57%) — — 18 (67%) 9 (65%) 4 (20%)c — 20 (43%) 7 (47%) 18 (60%)d 21 (84%) 19 (70%) ND 24 (69%) 15 (83%)d 14 (50%) 14 (74%) 31 (45%)d 5 (41%)d 11 (64%) 18 (60%)c 61 (94%) 39 (54%) 63 (40%) 7 (46%) 34 (76%)d 22 (74%) 30 (85%) 18 (72%)d 28 (69%)d 0 (0%)
11 (14%) — 2 (9%) 4 (15%) 1 (7%) 1 (5%) — ND 2 (13%) 13 (43%) 8 (32%) 1 (3%) 8 (19%) 7 (20%) 2 (11%) 4 (14%) 3 (15%) 8 (12%) 3 (25%) 6 (35%) 8 (27%) 17 (36%) 6 (13%) 29 (18%) 0 (0%) 4 (8%) 8 (26%) 6 (17%) 5 (20%) 9 (21%) 1 (2%)
59 81 21 25 10 13 15 32 15 25 12 25 42 35 12 28 17 18 11 17 22 65 72 157 15 45 29 35 25 41 43
(75) (100) (100) (92) (71) (65) (83) (100) (100) (83) (48) (92) (100) (100) (66) (100) (89) (26) (91) (100) (74) (100) (100) (100) (100) (100) (96) (100) (100) (100) (100)
ND 23 (28%) 16 (76%) 21 (77%) 7 (50%) ND ND 21 (65%) 11 (73%) 13 (43%) ND 15 (55%) ND 20 (57%) 0 (0%) ND 9 (47%) 0 (0%) 6 (50%) 17 (100%) ND ND 41 (63%) 121 (77%) ND 25 (55%) 23 (76%) 32 (91%) 16 (64%) 37 (90%) 17 (40%)
15 (19%) 16 (19%) 10 (47%) 15 (55%) 2 (14%) ND 2 (11%) 8 (25%) 6 (40%) 13 (43%) 11 (44%) 3 (11%) 33 (79%) 17 (49%) 1 (5%) ND 3 (15%) 2 (2%) 4 (33%) 17 (100%) ND 47 (62%) 44 (61%) 98 (62%) 0 (0%) 8 (17%) 17 (56%) 30 (85%) 17 (68%) 33 (80%) ND
15 (19%) 42 (51%) 13 (62%) 20 (74%) 9 (64%) 7 (35%) 12 (66%) 23 (71%) 9 (60%) 16 (53%) 1 (4%) 17 (62%) 42 (100%) 24 (68%) 10 (55%) 23 (82%) 12 (63%) 22 (32%) 5 (41%) 8 (47%) 22 (74%) ND 31 (43%) 98 (62%) 8 (53%) 37 (82%) 20 (66%) 35 (100%) 22 (88%) 23 (56%) 19 (44%)
a
Squamous cell carcinoma. Seventh cranial nerve; ND, no data. c Stell staging system. d Moody’s revision of the Pittsburgh staging system. b
the sensorineural hearing function and the facial nerve can potentially be preserved, if not invaded by the tumor. The STBR, performed through a temporo‐occipital craniotomy, is a medial extension of the LTBR that involves the labyrinth and the internal auditory canal. The resection extends from the carotid canal to the jugular fossa and could be extended to the posterior cranial fossa, posteriorly through the sigmoid sinus, and to the jugular bulb. In this procedure the sensorineural hearing function and the facial nerve are inevitably sacrificed. TTBR includes the petrous apex, depending on the tumor’s extension. In the LTBR, STBR, and TTBR the dura mater can be preserved or removed if involved by the tumor; in the latter case the gap has to be repaired with fascia [56]. The limits of an en bloc resection are planned preoperatively on the strength of imaging studies (contrast‐enhanced MRI) to ensure safe margins, and the tumor lies wholly within the resected volume. En bloc resection is based not on the extent of the tumor, but on the identification of an appropriate plane of dissection through normal healthy tissue. Piecemeal resection involves removing the soft portion of the tumor first, and then resecting its base of implant. Drilling the surrounding bone is part of the procedure, and the resection margins are checked intraoperatively for oncological radicality during the course of the piecemeal resection. This approach was first advocated by Heyer way back in 1899, with initially dismal results [57]. Several authors adopted piecemeal removal as their standard approach because of the technical Journal of Surgical Oncology
difficulties of en bloc procedures, which are not always justified by any significant improvement in the cure rate [23]. Nowadays, most otologists support en bloc resection of the lateral temporal bone [37,53,58], though some still maintain that tumors should be removed piecemeal [6,28]. It is not easy to achieve the radicality demanded by the principles of oncological surgery in cases of TBSCC because nearby noble structures such as the brain, internal carotid artery and jugular foramen limit the extent of resections. Current contraindications to curative surgery in TBSCC include cavernous sinus involvement, massive intracranial extension, unresectable neck disease, distant metastases, or poor general health [6]. In cases of intracranial spread with dural or brain involvement, curative surgical removal is indicated if en bloc resection can be achieved with tumor‐free margins [17]. Though technically feasible, whether or not temporal bone resection can be effective when the disease involves the internal carotid artery is hard to say because this situation is associated with a poor oncological outcome in any case. Carotid resection also significantly increases the risk of postoperative cerebral infarction [59] without improving survival [60]. In 1997, Moffat et al. [11] proposed an extended en bloc temporal bone resection procedure, preserving the internal carotid artery, and piecemeal removal of the petrous apex (if involved). Nowadays, subtotal/total en bloc petrosectomy is considered a safe and effective procedure for the majority of tumors extending to the middle and/or inner ear, and/or surrounding structures.
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Figure 2. High‐resolution temporal bone CT (axial view): A: Outer lateral temporal bone resection (sleeve resection): this resection preserves the temporo‐mandibular condyle anteriorly and the tympanic membrane medially; the lateral boundary is the pinna, the posterior boundary is the mastoid (which may be resected too). B: LTBR: en bloc resection involves the walls (anterior, posterior, superior, and inferior) of the external auditory canal and the middle ear, remaining lateral to the labyrinth ( ). The LTBR may extend anteriorly to the condyle and the glenoid fossa tissues ( ), posteriorly to beyond the sigmoid sinus ( ), inferiorly into the jugular bulb, going further into the internal carotid artery, and superiorly beyond the temporal plate to the middle cranial fossa floor. C: STBR: The en bloc subtotal temporal bone resection involves a medial extension of the LTBR through the labyrinth and the internal auditory canal ( ). It may extend to the whole internal auditory canal ( ) and posterior cranial fossa, and may be enlarged posteriorly through the sigmoid sinus ( ) and to the jugular bulb. D: TTBR: The en bloc total temporal bone resection is a medial extension of the STBR through the petrous apex depending on the tumor’s extension.
Neck Management (Table III) While treatment for the clinically positive neck is foregone, the role of elective neck dissection for TBSCC is controversial. Since this cancer develops within bony structures, lymph node metastases often occur when the primary tumor is already advanced. The incidence of cervical lymph node metastases is between 10% and 23% [9], and levels I and II are the most commonly involved [31]. In the available literature, radiological imaging is generally believed to be reasonably reliable for the purposes of detecting nodal metastases and planning curative neck dissection [19]. Although a few authors perform elective neck dissection routinely in all patients [23,26,53,62], most of the time this procedure is only considered for cases with clinical and/or radiological evidence of regional disease or parotid involvement. Nonetheless, Gidley and De Monte [6] recently reported that, although overall nodal involvement is low, and some tumors could be radically treated with LTBR alone, most cases require concomitant upper neck dissection (levels I–II). Elective neck dissection has been recommended in all cases of locally advanced TBSCC [23,29,61]. Such a procedure is also suggested in select high‐ risk cases based on histopathology and primary tumor extension [29] or to facilitate the resection and vessel exposure when flap reconstruction is advocated [6,23,29]. Journal of Surgical Oncology
Moffat et al. [23] suggested a selective supra‐homohyoid neck dissection (IIa–IIb–III) even in T1–T2 cases, not because of the frequency of cervical metastases, but for the purpose of appropriate staging and to select patients warranting adjuvant RT [61]. Occasionally, intraoperative sampling of clinically negative upper cervical lymph nodes has been used to ascertain whether neck dissection is indicated [23,63].
Parotid Gland Involvement (Table III) The parotid’s close proximity to the EAC and the fact that the gland contains first‐line draining nodes mean that it is at high risk of metastasis. Some authors nonetheless assume that a clinically negative parotid gland has no microscopic involvement [4], and therefore usually only consider parotidectomy when there is clinical and/or radiological evidence of the gland’s involvement or very close margins [39]. On the other hand, Zhang et al. [32] analyzed histopathological findings and concluded that tumors could extrude into the parotid gland even in the absence of any positive preoperative radiographic findings. Morris and colleagues claimed that a superficial parotidectomy is mandatory in all cases of advanced disease to control occult parotid node metastases. Some authors recommend superficial parotidectomy as part of en bloc
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resections for all tumors arising from the EAC because of the pre‐ auricular soft tissue’s weak resistance to invasion [29]. Although the deep lobe is rarely involved [4,29], total parotidectomy has been recommended in cases of direct parotid involvement [49].
Reconstruction Strategies Significant tissue removal with the extensive exposure of noble structures may be advocated to achieve oncological radicality. Reconstructions after temporal bone resections must necessarily aim for both anatomical and functional repairs. The aims of reconstruction strategies are thus to ensure a good skin wound closure and an adequate coverage of the dura mater so as to prevent cerebrospinal fluid leakage, and to compensate for loss of facial nerve function and help to restore hearing [65]. Flaps are now routinely used to reconstruct surgical defects after oncological demolitions for advanced disease. Moncrieff et al. [46] judged that defects wider than 9 cm require a free flap, while those smaller than 5 cm may be closed even with local tissue transfer, and a pedicled flap could be considered for defects between 5 and 9 cm wide. The initially‐used local skin flaps were subsequently replaced with pedicled myocutaneous flaps from the upper trunk. These flaps provided volume but their limitations lay in their length and tension compliance, which sometimes influenced their ability to close the upper edge of large defects. Nowadays, reconstruction with free flaps has become the standard of care for large skull base and cutaneous defects because they can be fashioned with well‐vascularized tissue of an appropriate size. They also allow for salvage procedures with a pedicled myocutaneous flap if the primary reconstruction fails. The radial forearm flap is considered the first choice because it is relatively easy to harvest and has a good blood supply through large‐caliber vessels. Other suggested sources of free flaps are the rectus abdominis and the latissimus dorsi muscles, the antero‐lateral thigh and the lateral arm flaps [46,65]. Modern surgical reconstructions can repair large surgical wounds [24] reducing the postoperative complications of wide resections performed to achieve free margins. Our literature review disclosed a perioperative mortality rate of no more than 5% in cases undergoing temporal bone resection and reconstruction. The overall postoperative morbidity rates varied considerably, depending on the tumor’s stage and the type of surgical procedure. Leong et al. [35] reported that most common complications occur in the immediate postoperative period, and relate mainly to the surgical wound (hematoma, infection, seroma); later complications (>2 weeks) were usually cases of wound dehiscence and flap necrosis. When it becomes mandatory to sacrifice the facial nerve due to its involvement by the tumor, nerve repair with a graft can be performed intraoperatively in all cases of complete paralysis of less than 12 months duration. Advanced age, postoperative RT and preoperative facial weakness are not absolute contraindications to immediate nerve reconstruction [65]. The great auricular nerve is generally considered a good option for this nerve graft [6]. Hearing loss has normally been accepted as unavoidable in order to achieve oncological radicality for temporal bone malignancies, but efforts have increased to restore patients to the best possible quality of life [66].
TREATMENT: NON‐SURGICAL APPROACHES
choice, followed by postoperative RT for advanced cases. Only a few recommend submitting all patients to adjuvant radiation [35,46]. So adjuvant RT is generally indicated for advanced tumors (T3–T4), or in the case of aggressive pathological features, such as perineural invasion, close (
REVIEW Temporal Bone Carcinoma. Current Diagnostic, Therapeutic, and Prognostic Concepts M. LIONELLO, MD,1* P. STRITONI, MD,2,3 M.C. FACCIOLO, MD,1 A. STAFFIERI, MD,1 A. MARTINI, MD,2 A. MAZZONI, MD,2 E. ZANOLETTI, MD,2 AND G. MARIONI, MD1 1
Department of Neurosciences, Otolaryngology Section, University of Padova, Padova, Italy 2 Department of Neurosciences, Otosurgery Unit, Padova Hospital, Padova, Italy 3 Visiting Doctor at Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
Temporal bone carcinoma is an uncommon aggressive malignancy. Its low incidence and the absence of a globally accepted staging system still make it difficult to compare different centers’ approaches and results. In this review of the main available studies dealing with temporal bone carcinoma since 1995, we consider its rational preoperative staging and assessment, compare the effectiveness of different treatments by tumor stage, and outline the main actuarial prognostic factors.
J. Surg. Oncol. 2014;110:383–392. ß 2014 Wiley Periodicals, Inc.
KEY WORDS: temporal bone; carcinoma; diagnosis; treatment; prognosis; biomarkers
EPIDEMIOLOGY AND PATHOGENESIS With an estimated 633,000 new cases in 2008, head and neck squamous cell carcinoma ranked as the 7th most common cancer worldwide when the global incidence and related mortality of malignancies was estimated for 182 countries by the International Agency for Research on Cancer as part of the GLOBOCAN scheme [1]. More recently, the American Cancer Society estimated that a total 1,660,290 new cases of cancer would occur in the United States in 2013, including 53,640 primary head and neck malignancies (excluding thyroid cancers) [2]. Temporal bone cancer accounts for less than 0.2% of all tumors involving the head and neck region [3]. There seem to be significant differences in its geographical distribution around the world: while it reportedly has an incidence of about 0.8–1 per million population per year in Western countries (England, Wales, and USA), carcinoma of the external auditory canal alone has been reported to have an incidence of 2.1 per million population per year in Singapore [4]. The gender distribution varies, but most authors have found a higher incidence in males. Among temporal bone malignancies, squamous cell carcinoma is by far the most common histological pattern [5]. After excluding primary locations outside the temporal bone, primary squamous cell carcinoma accounts for 60–80% of tumors arising in the auditory canal, middle ear, or mastoid cavity [6]. Like most epithelial malignancies, the majority of cancers of the external auditory canal and middle ear occur in the fifth and sixth decades of life [7,8]. A multifactorial etiology has been suggested for temporal bone carcinoma. For tumors arising from the external auditory canal (EAC) or pinna, exposure to ionizing radiation seems to be the most important risk factor (especially in fair‐skinned people), while a genetic susceptibility has been hypothesized for people not exposed to such radiation [9]. Head and neck radiation therapy has been considered a predisposing factor, especially in Asian people, where a higher prevalence of nasopharyngeal carcinomas treated primarily with radiotherapy (RT) was associated with a higher incidence of temporal bone squamous cell carcinomas (TBSCC) [10]. In the literature, a history of chronic suppurative otitis media has been associated with the onset of TBSCC [11], but there is no
ß 2014 Wiley Periodicals, Inc.
significant evidence to confirm this association [7]. A role has been suggested for chlorinated disinfectants in the etiopathogenesis of middle ear carcinoma [12] and for human papillomavirus in cases of TBSCC associated with inverted papilloma [13,14].
DIAGNOSIS: CLINICAL AND RADIOLOGICAL EVALUATION Despite its superficial position, temporal bone carcinoma is usually diagnosed late because its early signs and symptoms are non‐specific. Most patients initially complain of symptoms that are frequently attributed to inflammatory otological diseases. The most common clinical findings (Table I) consist of aural discharge (24–100%) or bleeding, otalgia (19–81%), and hearing loss (2–75%). Facial nerve paresis or palsy at presentation (7–64%) is considered a sign of advanced disease, as is evidence of an EAC mass. An early diagnosis is crucial for prompt treatment and a good outcome. Although tumors involving the lateral third of the EAC or the pinna might be thought to have a better prognosis, cutaneous carcinomas in the periauricular region, and carcinoma involving the EAC in particular, are reportedly more
Grant sponsor: University of Padova, Padova, Italy; Grant number: 60A07‐ 1341/12. M. Lionello and P. Stritoni contributed equally to the manuscript’s preparation. Conflict of Interest: None. *Correspondence to: Marco Lionello, MD, Department of Neurosciences, Otolaryngology Section, University of Padova, Padova, Italy. Fax: þ39‐049‐ 8213113. E‐mail: [email protected] Received 20 February 2014; Accepted 29 April 2014 DOI 10.1002/jso.23660 Published online 24 June 2014 in Wiley Online Library (wileyonlinelibrary.com).
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TABLE I. Demographics, Signs, and Symptoms at Presentation of TBSCC
References Pensak et al. [15] Manolidis et al. [16] Gal et al. [17] Chee et al. [4] Lim et al. [10] Moody et al. [18] Gillespie et al. [19] Nyrop et al. [20] Isipradit et al. [21] Lavieille et al. [22] Moffat et al. [23] Yin et al. [5] Lobo et al. [24] Chang et al. [25] Cristalli et al. [26] Ito et al. [27] Dean et al. [28] Morris et al. [29] Hosokawa et al. [30] Gidley et al. [31] Zhang et al. [32] Bacciu et al. [33] Lassig et al. [34] Leong et al. [35]
No. of cases
Male patients (%)
Mean age (%)
Otorrhea (%)
Otalgia (%)
Hearing loss (%)
Clinical involvement of VII cranial nerve (%)
46 81 21 14 18 32 15 20 16 30 39 95 19 12 17 16 65 72 15 157 43 45 30 35
54% 51% 90% 64% 55% ND 26% 50% 56% 90% 48% 63% 58% 83% 65% 43% 77% 74% 4% 76% 63% 56% 66% 68%
63 48 63 57 56 68 66 67 57 65 61 64 65 56 73 64 65 63 58 60 53 62 70 66
84% 24% ND 78% 55% 75% 73% 45% 69% 53% 69% 42% 68% 67% ND 94% ND ND ND 21% 70% 73% 33% 100%
74% 55% ND 35% 39% 81% 53% 35% 19% 53% 64% 24% 47% 34% ND 75% ND ND 27% 24% 81% 22% 43% 66%
62% 73% ND 21% ND 62% 33% 40% 37% 36% ND 2% 31% 8% ND 62% ND ND ND 46% 86% 75% ND ND
18% 64% 33% 35% 22% 25% 13% ND 12% 36% 7% 4% 21% ND 52% 18% 60% 20% 0% 38% 18% 17% 40% 46%
ND, no data.
aggressive than those arising in other areas of skin, probably due to multiple embryonic fusion planes facilitating tumor spread [36]. All patients with suspected temporal bone cancer should undergo a complete ENT assessment and micro‐otoscopy with extensive biopsies. Histology is crucial for a rational planning of treatment for temporal bone malignancies. According to current head and neck oncology guidelines, staging has to be done on radiological evidence of local and regional anatomical regions (high‐resolution temporal bone computerized tomography [CT] and contrast‐enhanced magnetic resonance imaging [MRI], neck ultrasonography with or without fine needle aspiration cytology on nodes). Positron emission tomography should be used to rule out distant metastases in advanced cases. Radiological imaging plays a central part in preoperative staging because the temporal bone’s anatomy hinders physical examination. High‐resolution CT is mandatory because it is highly sensitive in detecting early bone erosion, which is often the first sign of the disease spreading locally [19]. In 1990, Arriaga compared CT scans of 13 patients with closely‐correlating intraoperative and pathological evidence of the disease’s pathological extent [37]. High‐resolution CT scanning enables a reliable assessment of any invasion of the wall of the internal carotid artery canal, jugular bulb, and otic capsule [38]. The main limitations of CT imaging consist in the difficulty of distinguishing inflammatory mucosa from neoplastic tissue, particularly where there is no significant bone erosion [18]. Contrast‐ enhanced MRI reveals the tumor’s extent and better differentiates tumor from non‐neoplastic soft tissue [18]. It can identify petrous apex or temporo‐mandibular joint involvement [38], and dura mater invasion or intracranial extension [6]. It has also been demonstrated that contrast‐ enhanced MRI can nearly always detect parotid gland involvement and neck node metastases [19]. Bone CT and contrast‐enhanced MRI can be considered as complementary techniques for the purpose of correct staging. Journal of Surgical Oncology
STAGING No internationally accepted staging system is available for TBSCC (Table II). Several classifications have been proposed, but neither the International Union Against Cancer (UICC) nor the American Joint Committee on Cancer (AJCC) have so far endorsed any of these systems for staging ear and temporal bone tumors [39]. This continues to pose a problem when comparing results reported by different institutions (Fig. 1) and attempting to arrive at globally accepted guidelines on how to approach the disease. Among the many classifications proposed over time, Goodwin and Jessels described a three‐stage system correlated with tumor depth in 1980 [40], followed by Stell and McCormack suggesting a system in which any extratemporal spread was considered as T3 [41]. Clark et al. [42] then proposed differentiating between T3 lesions with a more favorable prognosis (with parotid, temporal‐ mandibular joint, and skin involvement) and those with a worse prognosis (when the dura mater and skull base are involved). The Pittsburgh University group came up with a clinical classification based on preoperative computed tomography and physical examination [37]. In 2000 Moody et al. suggested updating the Pittsburgh staging system to emphasize the importance of clinical facial nerve involvement, based on the assumption that nerve paralysis indicates invasion of the medial wall of the middle ear or mastoid. A clinical presentation with facial paresis or paralysis would thus be staged as T4 [18]. This is currently the most commonly used system for staging temporal bone carcinoma.
TREATMENT: SURGICAL OPTIONS Surgery for Primary Carcinoma (Table III) The treatment of TBSCC is challenging for head and neck surgeons and otologists. Over time many surgical approaches have been proposed with a view to improving the oncological safety of its treatment while minimizing the injury to nearby important neurovascular structures.
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Fig. 1. Distribution of papers available in the English language (at December 2013) on cohorts of patients with temporal bone carcinoma, published since 1995. The Pub‐Med (http://www.pubmed.gov) electronic database was searched. The search terms used were: “temporal bone cancer”, “temporal bone carcinoma”, “temporal bone malignancy”, “ear cancer”, “ear carcinoma”, “ear malignancy.” The “Related articles” option on the Pub‐Med homepage was also considered. Some papers were found in more than one search. The full texts of the publications identified were screened for original data and reference lists were checked for other relevant studies. One of the most debated issues when it comes to finding a rational surgical approach to temporal bone malignancies is the choice between en bloc versus piecemeal tumor removal. The en bloc approach was first mentioned in the 1950s by Campbell [54], and Parsons and Lewis [55], when it was considered technically more difficult but the only solution capable of ensuring radicality. In the light of these authors’ considerations, en bloc temporal bone resection has been classified as
lateral, subtotal or total (LTBR, STBR, and TTBR, respectively) (Fig. 2). The LTBR is an en bloc lateral petrosectomy through a temporal craniotomy: the outer hearing canal is completely removed, including the eardrum and part of the mastoid. The resection could be extended anteriorly to the condyle and the glenoid fossa, posteriorly beyond the sigmoid sinus, inferiorly to the jugular bulb and superiorly to the middle cranial fossa floor. Since the resection remains lateral to the labyrinth,
TABLE II. Available Staging Systems for TBSCC Primary tumor (T) ‐ AJCC staging system Tis Carcinoma in situ T1 Tumor 2 cm in greatest dimension with 2 cm with or without one additional high‐risk feature, or any size with 2 high‐risk features T3 Tumor with invasion of maxilla, mandible, orbit, or temporal bone T4 Tumor with invasion of (axial or appendicular) skeleton or perineural invasion of the cranial base Primary tumor (T) ‐ University of Pittsburgh staging system (Moody’s modified) T1 Tumor limited to the external auditory canal without bone erosion or evidence of soft tissue involvement T2 Tumor with limited external auditory canal bone erosion (not full‐thickness) or limited (6 cm in greatest dimension; or in bilateral or contralateral lymph nodes, none >6 cm in greatest dimension N3 Metastasis > 6 cm Distant metastasis (M) Mx Distant metastasis cannot be assessed M0 No distant metastasis M1 Distant metastasis Overall stage I T1 N0 II T2 N0 III T3 N0; T1 Nþ IV T4 N0; T2‐4 Nþ
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TABLE III. Clinicopathological Characteristics and Reported Treatment Modalities
References
Clinical involvement Surgery on Neck Adjuvant of VII c.n.b No. cT3‐4 No. of pNþ No. of T No. Parotidectomy No. dissection No. RT No. of No. of of cases (%) cases (%) cases (%) of cases (%) of cases (%) of cases (%) cases (%) cases SCCa (%)
Testa et al. [43] 79 Manolidis et al. [16] 81 Gal et al. [17] 21 Pfreundner et al. [44] 27 Chee et al. [4] 14 Hashi et al. [45] 20 Lim et al. [10] 18 Moody et al. [18] 32 Gillespie et al. [19] 15 Lavieille et al. [22] 30 Nakagawa et al. [38] 25 Martinez‐Devesa et al. [39] 27 Moncrieff et al. [46] 42 Moore et al. [47] 35 Bibas et al. [48] 18 Kunst et al. [49] 28 Lobo et al. [24] 19 Madsen et al. [50] 68 Chang et al. [25] 12 Cristalli et al. [26] 17 Prabhu et al. [51] 30 Dean et al. [28] 65 Morris et al. [29] 72 Gidley et al. [31] 157 Hosokawa et al. [30] 15 Bacciu et al. [33] 45 Lassig et al. [34] 30 Leong et al. [35] 35 Marioni et al. [52] 25 Zanoletti et al. [53] 41 Zhang et al. [32] 43
56 32 67 92 100 100 83 100 100 80 100 74 100 57 100 100 100 69 83 100 100 57 54 39 60 100 100 100 100 100 49
10 (13%) 52 (64%) 7 (33%) ND 5 (35%) ND 4 (22%) 8 (25%) 2 (13%) 11 (36%) ND ND ND ND ND ND 4 (21%) ND ND 9 (52%) ND 39 (60%) 13 (20%) 61 (38%) ND 8 (17%) 12 (40%) 16 (46%) ND ND 8 (18%)
45 (57%) — — 18 (67%) 9 (65%) 4 (20%)c — 20 (43%) 7 (47%) 18 (60%)d 21 (84%) 19 (70%) ND 24 (69%) 15 (83%)d 14 (50%) 14 (74%) 31 (45%)d 5 (41%)d 11 (64%) 18 (60%)c 61 (94%) 39 (54%) 63 (40%) 7 (46%) 34 (76%)d 22 (74%) 30 (85%) 18 (72%)d 28 (69%)d 0 (0%)
11 (14%) — 2 (9%) 4 (15%) 1 (7%) 1 (5%) — ND 2 (13%) 13 (43%) 8 (32%) 1 (3%) 8 (19%) 7 (20%) 2 (11%) 4 (14%) 3 (15%) 8 (12%) 3 (25%) 6 (35%) 8 (27%) 17 (36%) 6 (13%) 29 (18%) 0 (0%) 4 (8%) 8 (26%) 6 (17%) 5 (20%) 9 (21%) 1 (2%)
59 81 21 25 10 13 15 32 15 25 12 25 42 35 12 28 17 18 11 17 22 65 72 157 15 45 29 35 25 41 43
(75) (100) (100) (92) (71) (65) (83) (100) (100) (83) (48) (92) (100) (100) (66) (100) (89) (26) (91) (100) (74) (100) (100) (100) (100) (100) (96) (100) (100) (100) (100)
ND 23 (28%) 16 (76%) 21 (77%) 7 (50%) ND ND 21 (65%) 11 (73%) 13 (43%) ND 15 (55%) ND 20 (57%) 0 (0%) ND 9 (47%) 0 (0%) 6 (50%) 17 (100%) ND ND 41 (63%) 121 (77%) ND 25 (55%) 23 (76%) 32 (91%) 16 (64%) 37 (90%) 17 (40%)
15 (19%) 16 (19%) 10 (47%) 15 (55%) 2 (14%) ND 2 (11%) 8 (25%) 6 (40%) 13 (43%) 11 (44%) 3 (11%) 33 (79%) 17 (49%) 1 (5%) ND 3 (15%) 2 (2%) 4 (33%) 17 (100%) ND 47 (62%) 44 (61%) 98 (62%) 0 (0%) 8 (17%) 17 (56%) 30 (85%) 17 (68%) 33 (80%) ND
15 (19%) 42 (51%) 13 (62%) 20 (74%) 9 (64%) 7 (35%) 12 (66%) 23 (71%) 9 (60%) 16 (53%) 1 (4%) 17 (62%) 42 (100%) 24 (68%) 10 (55%) 23 (82%) 12 (63%) 22 (32%) 5 (41%) 8 (47%) 22 (74%) ND 31 (43%) 98 (62%) 8 (53%) 37 (82%) 20 (66%) 35 (100%) 22 (88%) 23 (56%) 19 (44%)
a
Squamous cell carcinoma. Seventh cranial nerve; ND, no data. c Stell staging system. d Moody’s revision of the Pittsburgh staging system. b
the sensorineural hearing function and the facial nerve can potentially be preserved, if not invaded by the tumor. The STBR, performed through a temporo‐occipital craniotomy, is a medial extension of the LTBR that involves the labyrinth and the internal auditory canal. The resection extends from the carotid canal to the jugular fossa and could be extended to the posterior cranial fossa, posteriorly through the sigmoid sinus, and to the jugular bulb. In this procedure the sensorineural hearing function and the facial nerve are inevitably sacrificed. TTBR includes the petrous apex, depending on the tumor’s extension. In the LTBR, STBR, and TTBR the dura mater can be preserved or removed if involved by the tumor; in the latter case the gap has to be repaired with fascia [56]. The limits of an en bloc resection are planned preoperatively on the strength of imaging studies (contrast‐enhanced MRI) to ensure safe margins, and the tumor lies wholly within the resected volume. En bloc resection is based not on the extent of the tumor, but on the identification of an appropriate plane of dissection through normal healthy tissue. Piecemeal resection involves removing the soft portion of the tumor first, and then resecting its base of implant. Drilling the surrounding bone is part of the procedure, and the resection margins are checked intraoperatively for oncological radicality during the course of the piecemeal resection. This approach was first advocated by Heyer way back in 1899, with initially dismal results [57]. Several authors adopted piecemeal removal as their standard approach because of the technical Journal of Surgical Oncology
difficulties of en bloc procedures, which are not always justified by any significant improvement in the cure rate [23]. Nowadays, most otologists support en bloc resection of the lateral temporal bone [37,53,58], though some still maintain that tumors should be removed piecemeal [6,28]. It is not easy to achieve the radicality demanded by the principles of oncological surgery in cases of TBSCC because nearby noble structures such as the brain, internal carotid artery and jugular foramen limit the extent of resections. Current contraindications to curative surgery in TBSCC include cavernous sinus involvement, massive intracranial extension, unresectable neck disease, distant metastases, or poor general health [6]. In cases of intracranial spread with dural or brain involvement, curative surgical removal is indicated if en bloc resection can be achieved with tumor‐free margins [17]. Though technically feasible, whether or not temporal bone resection can be effective when the disease involves the internal carotid artery is hard to say because this situation is associated with a poor oncological outcome in any case. Carotid resection also significantly increases the risk of postoperative cerebral infarction [59] without improving survival [60]. In 1997, Moffat et al. [11] proposed an extended en bloc temporal bone resection procedure, preserving the internal carotid artery, and piecemeal removal of the petrous apex (if involved). Nowadays, subtotal/total en bloc petrosectomy is considered a safe and effective procedure for the majority of tumors extending to the middle and/or inner ear, and/or surrounding structures.
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Figure 2. High‐resolution temporal bone CT (axial view): A: Outer lateral temporal bone resection (sleeve resection): this resection preserves the temporo‐mandibular condyle anteriorly and the tympanic membrane medially; the lateral boundary is the pinna, the posterior boundary is the mastoid (which may be resected too). B: LTBR: en bloc resection involves the walls (anterior, posterior, superior, and inferior) of the external auditory canal and the middle ear, remaining lateral to the labyrinth ( ). The LTBR may extend anteriorly to the condyle and the glenoid fossa tissues ( ), posteriorly to beyond the sigmoid sinus ( ), inferiorly into the jugular bulb, going further into the internal carotid artery, and superiorly beyond the temporal plate to the middle cranial fossa floor. C: STBR: The en bloc subtotal temporal bone resection involves a medial extension of the LTBR through the labyrinth and the internal auditory canal ( ). It may extend to the whole internal auditory canal ( ) and posterior cranial fossa, and may be enlarged posteriorly through the sigmoid sinus ( ) and to the jugular bulb. D: TTBR: The en bloc total temporal bone resection is a medial extension of the STBR through the petrous apex depending on the tumor’s extension.
Neck Management (Table III) While treatment for the clinically positive neck is foregone, the role of elective neck dissection for TBSCC is controversial. Since this cancer develops within bony structures, lymph node metastases often occur when the primary tumor is already advanced. The incidence of cervical lymph node metastases is between 10% and 23% [9], and levels I and II are the most commonly involved [31]. In the available literature, radiological imaging is generally believed to be reasonably reliable for the purposes of detecting nodal metastases and planning curative neck dissection [19]. Although a few authors perform elective neck dissection routinely in all patients [23,26,53,62], most of the time this procedure is only considered for cases with clinical and/or radiological evidence of regional disease or parotid involvement. Nonetheless, Gidley and De Monte [6] recently reported that, although overall nodal involvement is low, and some tumors could be radically treated with LTBR alone, most cases require concomitant upper neck dissection (levels I–II). Elective neck dissection has been recommended in all cases of locally advanced TBSCC [23,29,61]. Such a procedure is also suggested in select high‐ risk cases based on histopathology and primary tumor extension [29] or to facilitate the resection and vessel exposure when flap reconstruction is advocated [6,23,29]. Journal of Surgical Oncology
Moffat et al. [23] suggested a selective supra‐homohyoid neck dissection (IIa–IIb–III) even in T1–T2 cases, not because of the frequency of cervical metastases, but for the purpose of appropriate staging and to select patients warranting adjuvant RT [61]. Occasionally, intraoperative sampling of clinically negative upper cervical lymph nodes has been used to ascertain whether neck dissection is indicated [23,63].
Parotid Gland Involvement (Table III) The parotid’s close proximity to the EAC and the fact that the gland contains first‐line draining nodes mean that it is at high risk of metastasis. Some authors nonetheless assume that a clinically negative parotid gland has no microscopic involvement [4], and therefore usually only consider parotidectomy when there is clinical and/or radiological evidence of the gland’s involvement or very close margins [39]. On the other hand, Zhang et al. [32] analyzed histopathological findings and concluded that tumors could extrude into the parotid gland even in the absence of any positive preoperative radiographic findings. Morris and colleagues claimed that a superficial parotidectomy is mandatory in all cases of advanced disease to control occult parotid node metastases. Some authors recommend superficial parotidectomy as part of en bloc
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resections for all tumors arising from the EAC because of the pre‐ auricular soft tissue’s weak resistance to invasion [29]. Although the deep lobe is rarely involved [4,29], total parotidectomy has been recommended in cases of direct parotid involvement [49].
Reconstruction Strategies Significant tissue removal with the extensive exposure of noble structures may be advocated to achieve oncological radicality. Reconstructions after temporal bone resections must necessarily aim for both anatomical and functional repairs. The aims of reconstruction strategies are thus to ensure a good skin wound closure and an adequate coverage of the dura mater so as to prevent cerebrospinal fluid leakage, and to compensate for loss of facial nerve function and help to restore hearing [65]. Flaps are now routinely used to reconstruct surgical defects after oncological demolitions for advanced disease. Moncrieff et al. [46] judged that defects wider than 9 cm require a free flap, while those smaller than 5 cm may be closed even with local tissue transfer, and a pedicled flap could be considered for defects between 5 and 9 cm wide. The initially‐used local skin flaps were subsequently replaced with pedicled myocutaneous flaps from the upper trunk. These flaps provided volume but their limitations lay in their length and tension compliance, which sometimes influenced their ability to close the upper edge of large defects. Nowadays, reconstruction with free flaps has become the standard of care for large skull base and cutaneous defects because they can be fashioned with well‐vascularized tissue of an appropriate size. They also allow for salvage procedures with a pedicled myocutaneous flap if the primary reconstruction fails. The radial forearm flap is considered the first choice because it is relatively easy to harvest and has a good blood supply through large‐caliber vessels. Other suggested sources of free flaps are the rectus abdominis and the latissimus dorsi muscles, the antero‐lateral thigh and the lateral arm flaps [46,65]. Modern surgical reconstructions can repair large surgical wounds [24] reducing the postoperative complications of wide resections performed to achieve free margins. Our literature review disclosed a perioperative mortality rate of no more than 5% in cases undergoing temporal bone resection and reconstruction. The overall postoperative morbidity rates varied considerably, depending on the tumor’s stage and the type of surgical procedure. Leong et al. [35] reported that most common complications occur in the immediate postoperative period, and relate mainly to the surgical wound (hematoma, infection, seroma); later complications (>2 weeks) were usually cases of wound dehiscence and flap necrosis. When it becomes mandatory to sacrifice the facial nerve due to its involvement by the tumor, nerve repair with a graft can be performed intraoperatively in all cases of complete paralysis of less than 12 months duration. Advanced age, postoperative RT and preoperative facial weakness are not absolute contraindications to immediate nerve reconstruction [65]. The great auricular nerve is generally considered a good option for this nerve graft [6]. Hearing loss has normally been accepted as unavoidable in order to achieve oncological radicality for temporal bone malignancies, but efforts have increased to restore patients to the best possible quality of life [66].
TREATMENT: NON‐SURGICAL APPROACHES
choice, followed by postoperative RT for advanced cases. Only a few recommend submitting all patients to adjuvant radiation [35,46]. So adjuvant RT is generally indicated for advanced tumors (T3–T4), or in the case of aggressive pathological features, such as perineural invasion, close (
