title: A Tumour in Disguise in the Right Palm- Monophasic Synovial Sarcoma.
abstract: Synovial sarcoma is one of the poorly differentiated malignant soft tissue tumour occuring commonly among young adults in the extremities. We report a 50-year-old female presenting with a soft tissue mass in the right palm. On examination, a single firm and non tender swelling was noticed adjacent to the thenar muscles. Radiology suggested a benign soft tissue lesion. The swelling, clinically thought to be a lipoma, was excised and sent for histopathological examination. Microscopy showed a highly cellular tumour arranged in nests, cords and pseudo glandular pattern separated by dense fibrocollagenous tissue. An interesting and baffling finding was the presence of a distinct mucin vacuole in many of the tumour cells. A diagnosis of soft tissue sarcoma with epithelial features was considered and a panel of immunohistochemical stains done. Tumour cells showed strong positivity for cytokeratin 7, vimentin, EMA & Bcl2. CD 99 and S100 were focally positive. CD 34 and CEA were negative. In view of the above microscopic and immunohistochemical findings, a diagnosis of monophasic synovial sarcoma of epithelial type was rendered. This case is being documented for the rare morphological appearance of mucin vacuoles in a monophasic epithelial type synovial sarcoma.
authors.affiliation: Post Graduate, Department of Pathology, Sri Ramachandra Medical College and Research Institute , Chennai, India .
authors.forename: Vasugi Gramani
authors.initials: VG
authors.lastname: Arumugam
authors.affiliation: Professor, Department of Pathology, Sri Ramachandra Medical College , Chennai, India .
authors.forename: Sandhya
authors.initials: S
authors.lastname: Sundaram
authors.affiliation: Professor, Department of Oncology, Sri Ramachandra Medical College and Research Institute , Chennai, India .
authors.forename: Anita
authors.initials: A
authors.lastname: Ramesh
authors.affiliation: Professor, Department of Pathology, Sri Ramachandra Medical College and Research Institute , Chennai, India .
authors.forename: Prathiba
authors.initials: P
authors.lastname: Duvuru
authors.affiliation: Associate Professor, Department of Orthopedics, Sri Ramachandra Medical College , Chennai, India .
authors.forename: Srinivasa
authors.initials: S
authors.lastname: Rajappa
keywords: Epithelial type; Malignant soft tissue tumour; Mucin vacuoles