Medknow Publications on behalf of Indian Cancer Society
Abstract
Synovial sarcoma is uncommonly documented in the pelvis. Rarely, such
cases have dealt with molecular analysis. A 19-year-old boy presented
with pain and swelling in his left lower limb of two months duration.
He developed acute urinary retention four days prior to his hospital
admission, wherein radiological examination unraveled a large soft
tissue mass, displacing his pelvic muscles, along with a lytic lesion
involving his right pubic bone. Biopsy showed a cellular spindle cell
sarcoma, exhibiting hemangiopericytoma-like vascular pattern with focal
necrosis. Immunohistochemistry (IHC) showed positivity for vimentin,
BCL-2, calponin and MIC 2. Cytokeratin (CK) and epithelial membrane
antigen (EMA) were negative. MIB 1 count was 70% (high). P53 was
positive. Diagnosis of a poorly differentiated synovial sarcoma was
offered and confirmed with a positive t(X; 18) SYT-SSX2 translocation.
This case highlights the value of molecular analysis in diagnosis of a
synovial sarcoma at rare sites, especially when IHC results are
equivocal and the biopsy material is limited