J OralMaxillofacSurg 50:1227-1230,1992
Synovial Sarcoma of the Temporomandibular Joint R. DEAN WHITE, DDS, MS,* JAMES MAKAR JR, MD,t AND ROBERT M. STECKLER, MD+
Synovial sarcoma is a tumor of mesenchymal origin that is most commonly found in the extremities in close association with tendon sheaths, joint capsules, and bursae. Smith in 1927 coined the term synovioma,’ and Knox in 1936 suggested the name synovial sarcoma.2 However, Stuer in 1893 is credited with the first accurate description of this neoplasm.3 Its resemblance to normal synovium was recognized early in the literature, but its origin from synovial tissues has never been substantiated. It is reported to be the fourth most common sarcomatous tumor behind malignant fibrous histiocytoma, liposarcoma, and rhabdomyosarcoma, with an 8% to 10% incidence among all malignant tumors of soft somatic tissues.4 Nine percent of synovial sarcomas are situated in the head and neck. There have been two reported cases of synovial sarcoma arising in the temporomandibular joint; this report describes an additional case.
The patient had an end-to-end occlusion with bilateral posterior open bite, which was worse on the right side. The mandible could not be manually retruded. There were no areas of paresthesia or anesthesia, and no bruits or thrills could be detected. Transcranial radiographs showed good bony morphology of the condyle and fossa, which were without erosion, but the right condyle was markedly displaced anteriorly (Fig 1). A magnetic resonance image (MRI) of the joint showed an anteriorly displaced condyle, with a soft-tissue mass posterior to the condyle and possible fibrosis and adhesions (Fig 2). A differential diagnosis list that included intraarticular fibrosis, villonodular synovitis, ganglion cyst, salivary gland tumor, desmoid tumor, lymphoma, fibrosarcoma, synovial sarcoma, and metastatic tumor was considered. The patient was taken to the operating room, and a typical preauricular incision was used for exposure of the temporomandibular joint. The joint capsule was expanded, but was not penetrated by the underlying soft-tissue mass. A yellowish, firm mass was excised from the posterior ligament and posterior band of the articular disc. The lesion had eroded the glenoid fossa to the dura and extended medial and deep to the condyle and ramus. A frozen section was obtained, with a resulting preliminary diagnosis of fibrosarcoma. Permanent sections revealed a lesion primarily composed of plump, spindle-shaped cells arranged in intertwining fascicles that focally resembled a storiform pattern (Fig 3); a classic herringbone pattern was absent. Within the spindle-cell region, there were a few distinct, gland-like spaces lined by cuboidal to low columnar epithelial cells, which had nuclear characteristics similar to those of the spindle-shaped cells (Figs 4,5). Large areas of necrosis were present, and mitotic figures were conspicuous, with up to six per high-power field. The histologic findings were typical of a biphasic synovial sarcoma. A computed tomography scan was performed after the biopsy, and it showed an extensive tumor mass at the base of the skull extending to the margin of the nasopharynx and inferiorly to the pharynx. The patient was referred to aheadand-neck oncologic surgeon who, in conjunction with a neurosurgeon, performed a craniofacial resection of the right temporomandibular joint, including a right parotidectomy, supramyohyoid radical neck dissection, hemimandibulectomy, and partial right temporal bone resection (Fig 6). Immediate repair was performed with a split cranial bone graft and flap of pericranium. One month postoperatively the patient had a Stuphylococcus aureus infection, which responded to incision and drainage, vancomycin, and cefotaxime. During this admission, routine radiographs revealed extensive me&static disease in both lung fields and the right femoral head. He was treated
Report of Case A 57-year-old man was referred in June of 1990 by his dentist for right-sided temporomandibular joint pain with a 3-month history of not being able to occlude his teeth on the right side. He stated that as the pain increased his bite appeared to worsen; he graded the pain as 8 on a IO-point visual analog scale. He denied a history of trauma, bruxism, or clenching habits, and had not had occlusal appliance therapy or any other form of nonsurgical care. His medical history was noncontributory except for hypertension, for which he was being treated. Examination revealed an interincisal opening of 30 mm, with a 4-mm right deviation and 8-mm right and left lateral excursion. There was no noise heard in either joint, but there appeared to be a slight swelling in the right preauricular area.
* In private practice, Bedford, TX; Associate Baylor college bf Dentistry, Dallas, TX. t Pathologist. Harris HEB Hospital. Bedford. $ Surgica~Odcologist,Medical ‘City’Hospital; Address correspondence and reprint requests Central Dr, Bedford, TX 76021.
Clinical Professor, TX. Dallas, TX. to Dr White: 2 12 I
0 1992 American Association of Oral and Maxillofacial Surgeons 0278-2391/92/5011-0016$3.00/O
1227
1228
SYNOVIAL SARCOMA OF THE TMJ
FIGURE I. Transcranial radiograph showing normal bony architecture and anterior displacement of mandibular condyle.
with Cytoxan (Bristol-Myers,Evansville,IN) and Adriamycin (Adria Laboratories, Dublin, OH), and subsequently underwent 39 Gy of radiation therapy to the right base of the skull and 26 Gy to the right ilium. Fifteen months after the diagnosis had been made. the patient died of the disease.
Discussion Synovial sarcoma is most commonly found in adolescents and young adults between the ages of 15 and 40; 90% of the tumors are found in patients under the age of 50. Males appear to be slightly more susceptible than females, with reported ratios of 1.2: 1. There is no particular racial predilection.4
FJGURE 2. Magnetic resonance image, 2-D multislice T. proton density in oblique sag&al plane, demonstrating anterior position of the condyle and a soft-tissue mass posterior to it. Cine images demonstrated no translation of the condyle.
FIGURE 3. Photomicrograph of the spindle-cell component of the lesion. This region is suggestive of a storifonn pattern (hematoxylineosin stain, original magnification X 100).
The chief complaint of most patients is a painful, deep-seated mass or swelling, which may be accompanied by some limited range of motion. However, severe functional disturbances are not customary. The preoperative duration of symptoms is highly variable and is most commonly 2 to 4 years, although cases have been evaluated for as long as 20 years with a diagnosis of bursitis, synovitis, or arthritis. Trauma does not appear to be a predisposing factor. Intraarticular synovial sarcoma comprises less than 5% of all cases. The most common site is in the vicinity of the knee. In studies from the Armed Forces Institute of Pathology (AFIP), 83% of the cases were located in the extremities, 9% in the head and neck, and 8.1% in the region of the trunk.4 The majority of the cases in the head and neck appear to originate in the paravertebral connective-tissue spaces, and present as solitary, retropharyngeal or
FIGURE 4. Photomicrograph of the biphasic nature of the synovial sarcoma with plump, spindle-shaped cells and glandlike spaces lined by cuboidal to low columnar epithelioid cells (hematoxylin-eosin stain, original magnification X 100).
WHITE, MAKAR, AND STECKLER
parapharyngeal masses. Attie et al in 19’70reported the 1 lth case of cervical synovial sarcoma.’ In 1982 Shmookler et al reported 11 new cases of orofacial synovial sarcoma from the files of AFIP, which included four from the cheek region, two from the parotid region, three from the tonsillar region, and one from the submental region.6 Moore and Berke in 1987 reported five new cases of synovial sarcoma of the cheek and pharynx.7 Mitcherling et al reported the 25th case of synovial sarcoma of the neck in 1976.8 Dieckmann’ reported a case of primary synovial sarcoma of the temporomandibular joint in 1972, and DelBalso” reported an additional case of temporomandibular joint involvement in 1982. Most synovial sarcomas present radiographically as round or oval masses of moderate density, which are usually located in proximity to a large joint. One third of these present with multiple small and spotty radiopacities. The adjacent underlying bone generally tends to be uninvolved; however, in 10% to 15% of the cases superficial bone erosion may be present. The gross findings are indicative of the tumor’s rate of growth. Slow-growing lesions are usually well circumscribed and surrounded by a pseudocapsule. Most of the tumors are firmly attached to surrounding tendons, tendon sheaths, or the exterior wall of the joint capsule. Poorly differentiated tumors appear to be fiiable, with multiple areas of hemorrhage and necrosis. Histologically, the tumor is composed of two morphologically different types of cells that form the characteristic biphasic pattern: epithelioid cells, which resemble those of a carcinoma, and spindle-shaped cells, which resemble the fibroblasts of a fibrosarcoma. The epithelioid cells are characterized by large, round or oval, vesicular nuclei and pale-staining cytoplasm with discrete cellular borders. These cells are cuboidal to tall columnar and are arranged in solid cords, whorls, or nests, or border irregular pseudoglandular or cyst-
FIGURE 5. Higher magnification of Figure 4 shows the distinct glandlike spaces and intraluminal contents (hematoxylin-eosin stain, original magnification X400).
1229
FIGURE 6. Gross specimen of resected condyle with tumor mass in anterior synovial pouch. Resected disc resulted from the original biopsy.
like spaces that may contain granular or homogenous eosinophilic secretions. The most abundant component of this tumor is the fibrous-appearing tissue, which consists mostly of welloriented, plump, spindle-shaped cells with scant and indistinct cytoplasm and oval, dark-staining nuclei. Generally, the cells form solid, compact masses that are indistinguishable from a fibrosarcoma except for the absence of a well-defined herringbone pattern. Mitotic figures occur in both the epithelioid and spindleshaped cells, but generally only the more aggressive tumors exhibit more than two mitotic figures per highpower field. Monophasic fibrous synovial sarcoma is also a relatively uncommon neoplasm that does not differ in clinical presentation from the biphasic type. The monophasic epithelioid synovial sarcoma apparently also exists, but is extremely difficult to diagnose and can be mistaken for many metastatic and adnexal celltype carcinomas. Fortunately, purely epithelioid forms of this sarcoma are rare, and a biphasic pattern usually can be found. The recommended treatment consists of radical surgical excision followed by radiotherapy using highdosage cobalt or electron-beam radiation. Although the effectiveness of chemotherapeutic agents has not been proved, multidrug chemotherapy has been used in an attempt to prevent distant metastasis.
1230
ARTERIOVENOUS
Even with extremely aggressive treatment, the prognosis of synovial sarcoma is poor; Syear survival rates range from 36% to 5 l%, and lo-year survival rates range from 11.2% to 30%. There does not appear to be any relationship between microscopic type and survival rate. Metastatic lesions occur in almost half of the cases: the lung is the most prevalent site (94%) followed by regional lymph nodes and bone.
761 6. Shmookler
7.
9.
I. Smith LW: Synoviomata. Am J Pathol 3:355, I927 2. Knox LC: Synovial sarcoma: Report ofthree cases. Am J Cancer 28:461, 1936
OF MANDIBLE
3. Stuer J: Eine Ungenwoehnliche Geschwulst der Ellhogengelenksgegend. Inaug Diss Wuerzburg I893 4. Enzinger FM, Weiss SW: Soft Tissue Tumors, Synovial Sarcoma. St Louis, MO, Mosby, 1988, pp 659-688 5. Attie JN, Steckler RM, Platt N: Cervical synovial sarcoma, in Cancer, vol 25. Philadelphia, PA. Lippincott, 1970, pp 758-
8.
References
MALFORMATION
IO.
BM, Enzinger FM, Brannon RB: Oral facial synovial sarcoma. Cancer 50:269-276, 1982 Moore DM. Berke GS: Synovial sarcoma of the head and neck. Arch Otolaryngol Head Neck Surg 113:31 I-313, 1987 Mitcherling JJ, Collins EM, Tomich CE, et al: Synovial sarcoma of the neck: Report of case. Oral Surg 34:64-69. I976 Dieckmann J: Malignant synovioma of the temporomandibular joint. Deutsche Zahnaerztl Zeit 27:853-857. 1972 DelBalso AM, Pyatt RS, Busch RF. et al: Synovial cell sarcoma of the temporomandibular joint. Arch Otolaryngol 108:520522. 1982
J OralMaxillofacSurg 50:1230-1233.
1992
Recurrent Arteriovenous Malformation of the Mandible: A Case Report MUSTAFA AND J.M. SYMINGTON,
6. ABOUZGIA, BDS,* BDS, MSc, PHD, FDSRCS
Congenital arteriovenous malformations (AVMs) are vascular maldevelopments characterized by the presence of abnormal channels joining the arterial to the venous circulation without the interposition of a normal capillary bed; they usually have a high flow. Acquired arteriovenous fistulas are caused by injury. They commonly are single and involve a previously normal circulatory system. These anomalies enlarge by hemodynamic mechanisms rather than by cellular hyperplasia. Intrabony AVMs of the mandible are considered very rare. In their review of the literature, Gallagher et
Received from the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Toronto, and The Toronto Hospital, Toronto, Ontario, Canada. * Senior Resident. t Professor and Department Head. Address correspondence and reprint requests to Dr Symington: Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University ofToronto, 124 Edward St, Toronto, Ontario, M5G lG6 Canada. 0 1992 American 0278-2391/92/501
Association l-001
of Oral and Maxillofacial
7$3.00/O
Surgeons
(ENG)t
al’ found 124 published cases. Various treatment methods were described; of these, the most favorable technique was embolization, followed by resection. Radical surgical excision is reported to have good results, especially with smaller lesions. However, longterm follow-up usually is not reported. Rappaport and Rappaport2 believe that many communicating microfistulae coexist with a major fistula. They also believe that no treatment will effect a cure. While this is somewhat overstated, the principle is important in assessing treatment outcome. In the majority of AVMs, the communications between arteries and veins can be microscopic in size, leading to uncertainty about the anatomical extent of the lesion and resulting in inadequate surgical resections.2-6 Nonfunctioning microfistulae, with no blood flow, probably exist in the tissues surrounding an AVM.2-5 These microfistulae are not demonstrable by angiography.‘,* Coleman and Hoopesg believe that many of the shunts do not show on angiography, but changes in the peripheral resistance allow the shunts to open. Figure 1 represents a summary of the speculated events related to the mechanism of recurrence in congenital arteriovenous malformation.
Synovial Sarcoma of the Temporomandibular Joint R. DEAN WHITE, DDS, MS,* JAMES MAKAR JR, MD,t AND ROBERT M. STECKLER, MD+
Synovial sarcoma is a tumor of mesenchymal origin that is most commonly found in the extremities in close association with tendon sheaths, joint capsules, and bursae. Smith in 1927 coined the term synovioma,’ and Knox in 1936 suggested the name synovial sarcoma.2 However, Stuer in 1893 is credited with the first accurate description of this neoplasm.3 Its resemblance to normal synovium was recognized early in the literature, but its origin from synovial tissues has never been substantiated. It is reported to be the fourth most common sarcomatous tumor behind malignant fibrous histiocytoma, liposarcoma, and rhabdomyosarcoma, with an 8% to 10% incidence among all malignant tumors of soft somatic tissues.4 Nine percent of synovial sarcomas are situated in the head and neck. There have been two reported cases of synovial sarcoma arising in the temporomandibular joint; this report describes an additional case.
The patient had an end-to-end occlusion with bilateral posterior open bite, which was worse on the right side. The mandible could not be manually retruded. There were no areas of paresthesia or anesthesia, and no bruits or thrills could be detected. Transcranial radiographs showed good bony morphology of the condyle and fossa, which were without erosion, but the right condyle was markedly displaced anteriorly (Fig 1). A magnetic resonance image (MRI) of the joint showed an anteriorly displaced condyle, with a soft-tissue mass posterior to the condyle and possible fibrosis and adhesions (Fig 2). A differential diagnosis list that included intraarticular fibrosis, villonodular synovitis, ganglion cyst, salivary gland tumor, desmoid tumor, lymphoma, fibrosarcoma, synovial sarcoma, and metastatic tumor was considered. The patient was taken to the operating room, and a typical preauricular incision was used for exposure of the temporomandibular joint. The joint capsule was expanded, but was not penetrated by the underlying soft-tissue mass. A yellowish, firm mass was excised from the posterior ligament and posterior band of the articular disc. The lesion had eroded the glenoid fossa to the dura and extended medial and deep to the condyle and ramus. A frozen section was obtained, with a resulting preliminary diagnosis of fibrosarcoma. Permanent sections revealed a lesion primarily composed of plump, spindle-shaped cells arranged in intertwining fascicles that focally resembled a storiform pattern (Fig 3); a classic herringbone pattern was absent. Within the spindle-cell region, there were a few distinct, gland-like spaces lined by cuboidal to low columnar epithelial cells, which had nuclear characteristics similar to those of the spindle-shaped cells (Figs 4,5). Large areas of necrosis were present, and mitotic figures were conspicuous, with up to six per high-power field. The histologic findings were typical of a biphasic synovial sarcoma. A computed tomography scan was performed after the biopsy, and it showed an extensive tumor mass at the base of the skull extending to the margin of the nasopharynx and inferiorly to the pharynx. The patient was referred to aheadand-neck oncologic surgeon who, in conjunction with a neurosurgeon, performed a craniofacial resection of the right temporomandibular joint, including a right parotidectomy, supramyohyoid radical neck dissection, hemimandibulectomy, and partial right temporal bone resection (Fig 6). Immediate repair was performed with a split cranial bone graft and flap of pericranium. One month postoperatively the patient had a Stuphylococcus aureus infection, which responded to incision and drainage, vancomycin, and cefotaxime. During this admission, routine radiographs revealed extensive me&static disease in both lung fields and the right femoral head. He was treated
Report of Case A 57-year-old man was referred in June of 1990 by his dentist for right-sided temporomandibular joint pain with a 3-month history of not being able to occlude his teeth on the right side. He stated that as the pain increased his bite appeared to worsen; he graded the pain as 8 on a IO-point visual analog scale. He denied a history of trauma, bruxism, or clenching habits, and had not had occlusal appliance therapy or any other form of nonsurgical care. His medical history was noncontributory except for hypertension, for which he was being treated. Examination revealed an interincisal opening of 30 mm, with a 4-mm right deviation and 8-mm right and left lateral excursion. There was no noise heard in either joint, but there appeared to be a slight swelling in the right preauricular area.
* In private practice, Bedford, TX; Associate Baylor college bf Dentistry, Dallas, TX. t Pathologist. Harris HEB Hospital. Bedford. $ Surgica~Odcologist,Medical ‘City’Hospital; Address correspondence and reprint requests Central Dr, Bedford, TX 76021.
Clinical Professor, TX. Dallas, TX. to Dr White: 2 12 I
0 1992 American Association of Oral and Maxillofacial Surgeons 0278-2391/92/5011-0016$3.00/O
1227
1228
SYNOVIAL SARCOMA OF THE TMJ
FIGURE I. Transcranial radiograph showing normal bony architecture and anterior displacement of mandibular condyle.
with Cytoxan (Bristol-Myers,Evansville,IN) and Adriamycin (Adria Laboratories, Dublin, OH), and subsequently underwent 39 Gy of radiation therapy to the right base of the skull and 26 Gy to the right ilium. Fifteen months after the diagnosis had been made. the patient died of the disease.
Discussion Synovial sarcoma is most commonly found in adolescents and young adults between the ages of 15 and 40; 90% of the tumors are found in patients under the age of 50. Males appear to be slightly more susceptible than females, with reported ratios of 1.2: 1. There is no particular racial predilection.4
FJGURE 2. Magnetic resonance image, 2-D multislice T. proton density in oblique sag&al plane, demonstrating anterior position of the condyle and a soft-tissue mass posterior to it. Cine images demonstrated no translation of the condyle.
FIGURE 3. Photomicrograph of the spindle-cell component of the lesion. This region is suggestive of a storifonn pattern (hematoxylineosin stain, original magnification X 100).
The chief complaint of most patients is a painful, deep-seated mass or swelling, which may be accompanied by some limited range of motion. However, severe functional disturbances are not customary. The preoperative duration of symptoms is highly variable and is most commonly 2 to 4 years, although cases have been evaluated for as long as 20 years with a diagnosis of bursitis, synovitis, or arthritis. Trauma does not appear to be a predisposing factor. Intraarticular synovial sarcoma comprises less than 5% of all cases. The most common site is in the vicinity of the knee. In studies from the Armed Forces Institute of Pathology (AFIP), 83% of the cases were located in the extremities, 9% in the head and neck, and 8.1% in the region of the trunk.4 The majority of the cases in the head and neck appear to originate in the paravertebral connective-tissue spaces, and present as solitary, retropharyngeal or
FIGURE 4. Photomicrograph of the biphasic nature of the synovial sarcoma with plump, spindle-shaped cells and glandlike spaces lined by cuboidal to low columnar epithelioid cells (hematoxylin-eosin stain, original magnification X 100).
WHITE, MAKAR, AND STECKLER
parapharyngeal masses. Attie et al in 19’70reported the 1 lth case of cervical synovial sarcoma.’ In 1982 Shmookler et al reported 11 new cases of orofacial synovial sarcoma from the files of AFIP, which included four from the cheek region, two from the parotid region, three from the tonsillar region, and one from the submental region.6 Moore and Berke in 1987 reported five new cases of synovial sarcoma of the cheek and pharynx.7 Mitcherling et al reported the 25th case of synovial sarcoma of the neck in 1976.8 Dieckmann’ reported a case of primary synovial sarcoma of the temporomandibular joint in 1972, and DelBalso” reported an additional case of temporomandibular joint involvement in 1982. Most synovial sarcomas present radiographically as round or oval masses of moderate density, which are usually located in proximity to a large joint. One third of these present with multiple small and spotty radiopacities. The adjacent underlying bone generally tends to be uninvolved; however, in 10% to 15% of the cases superficial bone erosion may be present. The gross findings are indicative of the tumor’s rate of growth. Slow-growing lesions are usually well circumscribed and surrounded by a pseudocapsule. Most of the tumors are firmly attached to surrounding tendons, tendon sheaths, or the exterior wall of the joint capsule. Poorly differentiated tumors appear to be fiiable, with multiple areas of hemorrhage and necrosis. Histologically, the tumor is composed of two morphologically different types of cells that form the characteristic biphasic pattern: epithelioid cells, which resemble those of a carcinoma, and spindle-shaped cells, which resemble the fibroblasts of a fibrosarcoma. The epithelioid cells are characterized by large, round or oval, vesicular nuclei and pale-staining cytoplasm with discrete cellular borders. These cells are cuboidal to tall columnar and are arranged in solid cords, whorls, or nests, or border irregular pseudoglandular or cyst-
FIGURE 5. Higher magnification of Figure 4 shows the distinct glandlike spaces and intraluminal contents (hematoxylin-eosin stain, original magnification X400).
1229
FIGURE 6. Gross specimen of resected condyle with tumor mass in anterior synovial pouch. Resected disc resulted from the original biopsy.
like spaces that may contain granular or homogenous eosinophilic secretions. The most abundant component of this tumor is the fibrous-appearing tissue, which consists mostly of welloriented, plump, spindle-shaped cells with scant and indistinct cytoplasm and oval, dark-staining nuclei. Generally, the cells form solid, compact masses that are indistinguishable from a fibrosarcoma except for the absence of a well-defined herringbone pattern. Mitotic figures occur in both the epithelioid and spindleshaped cells, but generally only the more aggressive tumors exhibit more than two mitotic figures per highpower field. Monophasic fibrous synovial sarcoma is also a relatively uncommon neoplasm that does not differ in clinical presentation from the biphasic type. The monophasic epithelioid synovial sarcoma apparently also exists, but is extremely difficult to diagnose and can be mistaken for many metastatic and adnexal celltype carcinomas. Fortunately, purely epithelioid forms of this sarcoma are rare, and a biphasic pattern usually can be found. The recommended treatment consists of radical surgical excision followed by radiotherapy using highdosage cobalt or electron-beam radiation. Although the effectiveness of chemotherapeutic agents has not been proved, multidrug chemotherapy has been used in an attempt to prevent distant metastasis.
1230
ARTERIOVENOUS
Even with extremely aggressive treatment, the prognosis of synovial sarcoma is poor; Syear survival rates range from 36% to 5 l%, and lo-year survival rates range from 11.2% to 30%. There does not appear to be any relationship between microscopic type and survival rate. Metastatic lesions occur in almost half of the cases: the lung is the most prevalent site (94%) followed by regional lymph nodes and bone.
761 6. Shmookler
7.
9.
I. Smith LW: Synoviomata. Am J Pathol 3:355, I927 2. Knox LC: Synovial sarcoma: Report ofthree cases. Am J Cancer 28:461, 1936
OF MANDIBLE
3. Stuer J: Eine Ungenwoehnliche Geschwulst der Ellhogengelenksgegend. Inaug Diss Wuerzburg I893 4. Enzinger FM, Weiss SW: Soft Tissue Tumors, Synovial Sarcoma. St Louis, MO, Mosby, 1988, pp 659-688 5. Attie JN, Steckler RM, Platt N: Cervical synovial sarcoma, in Cancer, vol 25. Philadelphia, PA. Lippincott, 1970, pp 758-
8.
References
MALFORMATION
IO.
BM, Enzinger FM, Brannon RB: Oral facial synovial sarcoma. Cancer 50:269-276, 1982 Moore DM. Berke GS: Synovial sarcoma of the head and neck. Arch Otolaryngol Head Neck Surg 113:31 I-313, 1987 Mitcherling JJ, Collins EM, Tomich CE, et al: Synovial sarcoma of the neck: Report of case. Oral Surg 34:64-69. I976 Dieckmann J: Malignant synovioma of the temporomandibular joint. Deutsche Zahnaerztl Zeit 27:853-857. 1972 DelBalso AM, Pyatt RS, Busch RF. et al: Synovial cell sarcoma of the temporomandibular joint. Arch Otolaryngol 108:520522. 1982
J OralMaxillofacSurg 50:1230-1233.
1992
Recurrent Arteriovenous Malformation of the Mandible: A Case Report MUSTAFA AND J.M. SYMINGTON,
6. ABOUZGIA, BDS,* BDS, MSc, PHD, FDSRCS
Congenital arteriovenous malformations (AVMs) are vascular maldevelopments characterized by the presence of abnormal channels joining the arterial to the venous circulation without the interposition of a normal capillary bed; they usually have a high flow. Acquired arteriovenous fistulas are caused by injury. They commonly are single and involve a previously normal circulatory system. These anomalies enlarge by hemodynamic mechanisms rather than by cellular hyperplasia. Intrabony AVMs of the mandible are considered very rare. In their review of the literature, Gallagher et
Received from the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Toronto, and The Toronto Hospital, Toronto, Ontario, Canada. * Senior Resident. t Professor and Department Head. Address correspondence and reprint requests to Dr Symington: Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University ofToronto, 124 Edward St, Toronto, Ontario, M5G lG6 Canada. 0 1992 American 0278-2391/92/501
Association l-001
of Oral and Maxillofacial
7$3.00/O
Surgeons
(ENG)t
al’ found 124 published cases. Various treatment methods were described; of these, the most favorable technique was embolization, followed by resection. Radical surgical excision is reported to have good results, especially with smaller lesions. However, longterm follow-up usually is not reported. Rappaport and Rappaport2 believe that many communicating microfistulae coexist with a major fistula. They also believe that no treatment will effect a cure. While this is somewhat overstated, the principle is important in assessing treatment outcome. In the majority of AVMs, the communications between arteries and veins can be microscopic in size, leading to uncertainty about the anatomical extent of the lesion and resulting in inadequate surgical resections.2-6 Nonfunctioning microfistulae, with no blood flow, probably exist in the tissues surrounding an AVM.2-5 These microfistulae are not demonstrable by angiography.‘,* Coleman and Hoopesg believe that many of the shunts do not show on angiography, but changes in the peripheral resistance allow the shunts to open. Figure 1 represents a summary of the speculated events related to the mechanism of recurrence in congenital arteriovenous malformation.
