Case Report

Large solitary fibrous tumour of the retroperitoneum: a case report and review of the literature

Scottish Medical Journal 58(4) e26–e30 ! The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0036933013508050 scm.sagepub.com

M Orsaria1, S Marzinotto1 and L Mariuzzi2

Abstract Introduction: This report describes an unusual case of a large solitary fibrous tumour (SFT) arising in the retroperitoneum. Case presentation: A 53-year-old woman presented at the Emergency Department with urinary retention and lumbar pain. The urological examination was negative, whereas a presacral retroperitoneal mass was disclosed on ultrasound. The laboratory studies, including tumour markers, were negative. On laparotomy, it was not possible to remove the mass completely due to the difficulty of dissecting it free of the sacrum. Grossly, the fragment had a yellowish-white surface, with areas of necrosis and haemorrhage. On immunohistochemistry, tumour cells were positive for CD34, CD99 and Bcl-2 and negative for CD45, synaptophysin, chromogranin, S100, neuron-specific enolase, CK AE1-AE3, CK7, Wilms’ tumour 1, smooth muscle actin, factor VIII, myogenin, epithelial membrane antigen, thyroid transcription factor-1 and CD117, leading to a diagnosis of SFT. Molecular investigation ruled out synovial sarcoma. Conclusion: Although SFT usually has a favourable prognosis, close follow-up is recommended due to the limited information on its long-term behaviour.

Keywords Solitary fibrous tumour, retroperitoneum, CD34, Bcl-2

Introduction

Case presentation

Solitary fibrous tumour (SFT), also called solitary mesothelioma, benign fibrous mesothelioma or localised fibrous tumour of the pleura, based on histological features and on the fact that it most often arises in the pleura, is an uncommon neoplasm.1 Its histogenesis is controversial, with early studies suggesting a mesothelial or mesenchymal origin of probable fibroblastic type. Recent immunohistochemical and ultrastructural research strongly supports a mesenchymal origin.2 Reports of sporadic cases of SFT at various extrapleural sites, such as mediastinum, pericardium, nasal cavity, peritoneum,3 retroperitoneum4 and liver, have been increasing. Despite the difficulty of diagnosing it, due to its rarity and variable histological features, it is frequently a slow-growing mass with a favourable prognosis. This report describes an unusual, large SFT located in the retroperitoneum.

A 53-year-old woman presented at the Emergency Department of the University Hospital of Udine (Udine, Italy) with urinary retention and bilateral lumbar pain. The clinical urological examination was negative, but a large, not clearly demarcated pelvic mass containing both solid and cystic areas was disclosed on abdominal ultrasound. The pelvic mass was

1 Medical Doctor (MD), Department of Pathology, University Hospital of Udine, Italy 2 Assistant Professor, Department of Pathology, University Hospital of Udine, Italy

Corresponding author: Maria Orsaria, Department of Pathology, Azienda OspedalieroUniversitaria di Udine, Piazzale S. Maria della Misericordia 15, Udine 33100, Italy. Email: [email protected]

Downloaded from scm.sagepub.com at Kungl Tekniska Hogskolan / Royal Institute of Technology on July 2, 2015

Orsaria et al.

e27

not grossly obvious. The patient’s height and weight were 163 cm and 62.5 kg, respectively; her blood pressure was 124/77 mmHg and body temperature was 36.5 C. Laboratory tests were within normal ranges and tumour markers were negative. An abdominal computerised tomography scan showed a presacral retroperitoneal mass measuring 11  11  12 cm with solid and cystic areas, compressing the cervix. A retroperitoneal tumour was diagnosed and scheduled for removal. On laparotomy, a mass of about 12 cm in diameter was seen to press against the sacrum, compressing the cervix and left ureter. Most of the tumour was encapsulated and easily ablated, but a small portion that was in contact with the sacrum could not be dissected free and therefore had to be left in situ.

Investigations Tissues were fixed in buffered formalin, paraffin embedded and routinely processed for histological diagnosis. For immunohistochemistry, the Dako REALTM EnVisionTM Detection System (Glostrup, Denmark), Peroxidase/DAB+, Rabbit/Mouse Code K5007 method was used. The antisera employed are listed in Table 1, together with their source, dilution and antigen retrieval method.

Results The resected specimens and some tissue fragments, labelled as ‘capsule and content of a cystic neoplasm found in the retroperitoneum’, were delivered to the Department of Pathology (University Hospital of Udine). On cross-section, the mass was yellowish, fibrous and multicystic, with areas of focal necrosis and haemorrhage and septa containing coagulated material. Histologically, the tumour had variable cellularity, admixed hyper- and hypocellular areas, consisting of a mixture of haphazard, storiform or short fascicular arrangements of spindle cells, and dense collagen bands with a patternless appearance. The round to spindleshaped tumour cells had scanty cytoplasm with indistinct borders, dispersed chromatin within the vesicular nuclei and seven mitoses per 10 high-power fields. The neoplasm also showed some small, thin vessels with a hemangiopericytoma-like appearance (Figure 1). On immunohistochemistry, tumour cells were positive for CD34, CD99 and Bcl-2 (Figure 2) and negative for CD45, synaptophysin, chromogranin, S-100, neuron-specific enolase (NSE), CK AE1-AE3, CK7, Wilms’ tumour 1 (WT1), smooth muscle actin, factor VIII, myogenin, epithelial membrane antigen (EMA), thyroid transcription factor-1 (TTF-1) and CD117, confirming the initial diagnosis of SFT. A synovial sarcoma was ruled out by polymerase chain reaction,

Table 1. Antibodies employed for immunohistochemistry. Antibody

Clone, source

Dilution

CD34 CD99

QBEnd10, Dako 12E7, Dako

1:100 1:100

Bcl-2

124, Dako

1:100

CD45

2B11 + PD7/26, Dako

1:100

Synaptophysin

SY38, Dako

1:200

Chromogranin A

DAK-A3, Dako

1:200

S100

Polyclonal, Dako

1:1000

NSE

BBS/NC/VI-H14, Dako

1:2000

Cytokeratin Cytokeratin 7

AE1/AE3, Dako OV-TL 12/30, Dako

1:200 1:100

WT1

6F-H2, Dako

1:50

SMA

1A4; Dako

1:200

Factor VIII

F8/86, Dako

1:20

Myogenin

F5D, Dako

1:50

EMA

E29, Dako

1:500

TTF-1

8G7G3/1, Dako

1:50

CD117, c-kit

Polyclonal, Dako

1:100

NSE: neuron-specific enolase; WT1: Wilms’ tumour 1; SMA: smooth muscle actin; EMA: epithelial membrane antigen; TTF-1: thyroid transcription factor-1.

which excluded the presence of SYT-SSX1 or SYT-SSX2 fusion transcript. The postoperative course was uneventful. Increased CA125 levels in the early follow-up period led to a ‘sarcoma-like’ chemotherapy regimen (epirubicin-iphosphamide + GCSF), with the possibility of subsequent radiotherapy to treat the residual sacral neoplasm. A further abdominal ultrasound scan performed in the same period disclosed four hepatic nodules consistent with angioma lesions that were assessed to require follow-up. No evidence of an SFT recurrence was found in the subsequent 24 months.

Discussion SFTs are rare spindle-cell neoplasms found principally in the pleura, with a reported incidence of 2.8 cases per 100,000 registrations at the Mayo Clinic (Rochester, MN, USA).1 Occasionally, they have also been described at other sites, including mediastinum, pericardium, nasal cavity, peritoneum,3 retroperitoneum,4 liver and kidney. SFT was initially thought to derive from the mesothelium1 and was, therefore, called solitary/localised mesothelioma. However, recent electron microscopic and immunohistochemical evidence has defined the fibrous tumours in this category as solitary/localised fibrous tumours derived from the connective tissue located under the mesothelium.2 Most SFTs are large (9 cm), solid, firm, white and well-encapsulated, with a broad size range. Histologically, they have either a patternless

Downloaded from scm.sagepub.com at Kungl Tekniska Hogskolan / Royal Institute of Technology on July 2, 2015

e28

Scottish Medical Journal 58(4)

Figure 1. Photomicrographs of the tumour showing (a) an admixture of oval and spindle cells surrounded by abundant collagen with haphazard, storiform or short fascicular arrangement (hematoxylin-eosin, original magnification  100) and (b) a hemangiopericytoma-like appearance with small vessels (hematoxylin-eosin, original magnification  100). (c) A higher magnification of the image shown in (b) (hematoxylin-eosin, original magnification  200).

appearance, which is more common, or a hemangiopericytoma-like appearance with prominent vascularity. Both patterns were detected in the present case. The main entities to be considered in the differential diagnosis of an SFT are hemangiopericytoma, synovial

Figure 2. The immunophenotype of the tumour characterised by strong cytoplasmic immunoreactivity for (a) CD34 (original magnification  200) and (b) CD99 (original magnification  400); (c) weak cytoplasmic immunoreactivity for Bcl-2 (original magnification  200).

sarcoma, leiomyosarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumour, dedifferentiated liposarcoma, desmoid tumour, cellular angiofibroma, GIST,5 dermatofibrosarcoma protuberans, desmoplastic mesothelioma, spindle-cell thymoma and spindle-cell carcinoma.6,7 Immunohistochemical staining helps establish the diagnosis. In particular, CD34 is considered to be a

Downloaded from scm.sagepub.com at Kungl Tekniska Hogskolan / Royal Institute of Technology on July 2, 2015

Orsaria et al.

e29

positive marker for SFT.8,9 Albeit not specific for this neoplasm, CD34, which is expressed in hematopoietic precursor cells and hemangiopericytes, in conjunction with a lack of expression of other immunohistochemical markers, can help exclude a variety of soft-tissue tumours. In a recent immunohistochemical study of Bcl-2 protein, which suppresses apoptosis and CD34 in SFT, Hasegawa et al.7 found that they were expressed, respectively, in 75% and 100% of extrathoracic SFTs and concluded that combined Bcl-2 and CD34 staining is useful in distinguishing this entity from other spindle-cell neoplasms. The tumour in the present case was immunoreactive for both. Recent studies have shown that loss of CD34 and p53 overexpression is related to a malignant phenotype and to a fatal outcome in patients with pleural SFT. Bcl-2-positive phenotypes have been demonstrated to be associated with a better prognosis in several neoplasms, including SFT.6 SFT is cytogenetically heterogeneous; demonstrable cytogenetic aberrations are uncommon in smaller SFTs, but are found in most SFTs exceeding 10 cm in diameter (trisomy 21 or 8).7 Although SFT is regarded as benign, isolated cases of recurrence and distant metastasis have been reported. England et al.10 described a high (36.8%) incidence of malignancy of pleural SFT, accounting for 82 of 223 cases and proposed that SFTs should be regarded as malignant if one or more of the following histologic features are present: high cellularity with crowded and overlapping nuclei, high mitotic activity and more than four mitotic figures per 10 high-power fields. Several other authors believe that clinical behaviour cannot always be predicted from the morphologic features, emphasising resectability as a reliable prognostic factor.1,6,7,11,12 Morimitsu et al.11 found that most of the extrapleural SFTs they studied behaved in a benign fashion, even those with malignant histological features, demonstrating the difficulty of predicting clinical outcome. Hasegawa et al.7 examined the features of 24 extrathoracic SFTs and reported a similar tendency. Yokoi et al.13 found that tumours with malignant histological features or a fatal outcome showed loss of CD34 expression and high p53 reactivity, suggesting the usefulness of immunohistochemical investigations in the clinical diagnosis of malignant SFTs. Lesions arising in the mediastinum, abdomen, pelvis and retroperitoneum also tend to behave more aggressively than those in the limbs. Metastases are most frequent to lung, bone and liver.14 Although most extrapleural SFTs are associated with a favourable prognosis, surgical excision with clear margins and careful, long-term follow-up are recommended by several authors,7,11 since malignant SFTs have been described.10 The major prognostic factor in

pleural SFTs is not their histological appearance but their resectability.10,15 Re-excision with negative margins is recommended for recurrences of peritoneal SFTs,7,12 while the value of adjuvant chemotherapy or radiation therapy is controversial.12 In the present case, it was not possible to accomplish complete resection because the tumour was not wholly encapsulated and was attached to the sacrum. The patient received ‘sarcoma-like’ chemotherapy (epirubicin-iphosphamide + GCSF) and no evidence of SFT recurrence has been detected at 24 months.

Conclusions An SFT case of the pelvic retroperitoneum was described and the following points should be emphasised: (i) A preoperative diagnosis of SFT is difficult, because clinical symptoms, physical examination and imaging findings are not conclusive; pathological and immunohistochemical examination of the resected tumour is required for the final diagnosis. (ii) SFT of the retroperitoneum is a rare entity. (iii) Immunoreactivity for CD34 and Bcl-2 helps in the differential diagnosis and suggests a favourable outcome.6 (iv) Most SFTs are benign; however, some malignant SFT have been described. (v) The definition of malignancy involves the degree of local invasion, local recurrence and distant metastases. (vi) SFT is regarded as benign or malignant based on histological features that include high cellularity, mitotic activity, pleomorphism, haemorrhage and necrosis.10 (vii) The histological appearance and growth pattern of SFTs are not always good indicators of clinical outcome.10 (viii) The most important prognostic factor is not histological appearance but resectability.10

Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Declaration of conflicting interests None declared.

Author contributions MO collected the data, conceived, designed and drafted the manuscript, revising it critically for important intellectual

Downloaded from scm.sagepub.com at Kungl Tekniska Hogskolan / Royal Institute of Technology on July 2, 2015

e30

Scottish Medical Journal 58(4)

content; and gave final approval of the version to be published. SM and LM conceived the manuscript and participated in its design, revised it critically for important intellectual content and gave the final approval of the version to be published.

References 1. Briselli M, Mark EJ and Dickersin GR. Solitary fibrous tumors of the pleura. Eight new cases and review of 360 cases in the literature. Cancer 1981; 47: 2678–2689. 2. Dervan PA, Tobin B and O’Conner M. Solitary (localized) fibrous mesothelioma. Evidence against mesothelial cell origin. Histopathology 1986; 10: 867–875. 3. Kubota Y, Kawai N, Tozawa K, et al. Solitary fibrous tumor of the peritoneum found in the prevesical space. Urol Int 2000; 65: 53–56. 4. Piazza R, Blandamura S, Zattoni F, et al. Solitary fibrous tumour of the retroperitoneum mimicking a renal mass. Int Urol Nephrol 1996; 28: 751–754. 5. Shidham VB, Chivukula M, Gupta D, et al. Immunohistochemical comparison of gastrointestinal stromal tumor and solitary fibrous tumor. Arch Pathol Lab Med 2002; 126: 1189–1192. 6. Takizawa I, Saito T, Kitamura Y, et al. Primary solitary fibrous tumor (SFT) in the retroperitoneum. Urol Oncol 2008; 26: 254–259. 7. Hasegawa T, Matsuno Y, Shimoda T, et al. Extrathoracic solitary fibrous tumors: their histological variability and potentially aggressive behavior. Hum Pathol 1999; 30: 1464–1473.

8. Cheryl AH and Miettinen M. Solitary fibrous tumor: histological and immunohistochemical spectrum of benign and malignant variants presenting at different sites. Hum Pathol 1995; 26: 440–449. 9. Westra WH, Gerald WL and Rosai J. Solitary fibrous tumor. Consistent CD34 immunoreactivity and occurrence in the orbit. Am J Surg Pathol 1994; 18: 992–998. 10. England DM, Hochholzer L and McCarthy MJ. Localized benign and malignant fibrous tumors of the pleura. A clinicopathologic review of 223 cases. Am J Surg Pathol 1989; 13: 640–658. 11. Morimitsu Y, Nakajima M, Hisaoka M, et al. Extrapleural solitary fibrous tumor: clinicopathologic study of 17 cases and molecular analysis of the p53 pathway. APMIS 2000; 108: 617–625. 12. Vallat-Decouvelaere AV, Dry SM and Fletcher C. Atypical and malignant solitary fibrous tumors in extrathoracic locations: evidence of their comparability to intra-thoracic tumors. Am J Surg Pathol 1998; 22: 1501–1511. 13. Yokoi T, Tsuzuki T, Yatabe Y, et al. Solitary fibrous tumour: significance of p53 and CD34 immunoreactivity in its malignant transformation. Histopathology 1998; 32: 423–432. 14. Fletcher CDM, Unni KK and Mertens F. Pathology and genetics of tumours of soft tissue and bone. WHO classification of tumours. Vol. 5, Lyon: IARC press, 2002. 15. Tanaka M, Sawai H, Okada Y, et al. Malignant solitary fibrous tumor originating from the peritoneum and review of the literature. Med Sci Monit 2006; 12: CS95–CS98.

Downloaded from scm.sagepub.com at Kungl Tekniska Hogskolan / Royal Institute of Technology on July 2, 2015

Large solitary fibrous tumour of the retroperitoneum: a case report and review of the literature.

This report describes an unusual case of a large solitary fibrous tumour (SFT) arising in the retroperitoneum...
543KB Sizes 0 Downloads 0 Views