Synovial sarcoma (SS) is a malignant soft tissue tumour of uncertain histogenesis which is defined by the translocation t(X;18) that produces the fusion oncogenes SYT-SSX. The emergence of transducer-like enhancer of split 1 (TLE1) as a new immunohistochemical (IHC) marker for SS has offered an alternative to pathologists in differentiating SS from other histological mimics, especially in the setting of limited molecular facilities. We investigated the utility of IHC TLE1 expression against histomorphological features and other IHC markers in SS and non-SS tumours. Twenty-six cases of histologically diagnosed SS and 7 non-SS (for which SS was in the differential diagnosis) were subjected to TLE1 IHC staining, which was graded from 0 to 3+. Of the 26 SS cases, 12 each were biphasic and monophasic types and 2 were poorly-differentiated. TLE1 was expressed in 22/26 (84.6%) SS cases, of which 11/12 (91.7%) were biphasic, 10/12 (83.3%) monophasic and 1/2 (50%) poorly-differentiated tumours. Two of 7 (28.6%) non-SS cases were positive for TLE1. Immunopositivity of SS and non-SS cases for EMA were 20/26 (76.9%) and 2/7 (28.6%) respectively and for CK7 were 7/26 (26.9%) and 0/7 (0%) respectively. All cases were negative for CD34. Consistent histomorphological features for SS included mild nuclear pleomorphism, alternating tumour cellularity, fascicular growth pattern and thick ropy stromal collagen. In conclusion, TLE1 is not a stand-alone diagnostic IHC marker for SS. However, in the absence of molecular studies, it can contribute added diagnostic value in combination with morphological evaluation and other IHC markers such as EMA and CD34.
Head and neck synovial sarcoma is rare. We report the case of a 71-year-old man who presented with progressive dysphagia, odynophagia, shortness of breath on exertion and hoarseness of voice. Nasendoscopy revealed a smooth, non-fungating, non-ulcerative mass arising from the left lateral pharyngeal wall. CT showed a well-defined, heterogenous enhancing lesion arising from the left pyriform fossa. Initial biopsy taken was inconclusive and patient underwent a transcervical complete excision of the tumour, where histopathological analysis confirmed the diagnosis of monophasic synovial sarcoma of the left pyriform fossa. This patient also received adjuvant radiotherapy postoperatively and remained disease free 1 year after completion of treatment.
Mycetoma, also commonly referred to as Madura foot, is statistically rare in the United States. However, it is endemic to other parts of the world. It is a pseudotumor characterized by a triad of tumefaction, draining sinuses, and grains. Two types exist, with each caused by different groups of organisms that require different treatment approaches. Therefore, the exact diagnosis and culture of the organism is vital to successful treatment outcomes. Synovial sarcoma, in contrast, is a malignancy much more commonly seen in the United States. It is characterized by a well-circumscribed, often palpable, mass that is usually well delineated on magnetic resonance imaging. It has characteristic histologic and genetic features that help distinguish it from other soft tissue masses. We present a case of a soft tissue mass diagnosed in the United States. The patient had several clinical and radiographic features of synovial sarcoma but the histologic outcome was mycetoma. The case is followed by a review of the published data.
Synovial sarcoma is a rare soft tissue sarcoma of the head and neck region involving the parapharyngeal space. The diagnosis of synovial sarcoma can be very challenging to the pathologists. We present a rare case of parapharyngeal synovial sarcoma in a young female patient who had a two-month history of left cervical intumescent mass at level II. The fine needle aspiration cytology of the mass was proved inconclusive. Transcervical excision of the mass was performed and the first case of parapharyngeal sarcoma was identified in our center by fluorescence in situ hybridization (FISH) technique. Repeat imaging revealed residual tumor. The patient successfully underwent a second excision of the residual tumor and received adjuvant radiotherapy.