Sarcoma sinovial renal primario: presentación de un caso con estudio molecular

Synovial sarcoma (SS) of the kidney was first reported by Argani et al. in 2000. We report a case of a renal monophasic SS of intermediate grade in 42-year-old man with a solid-cystic, well-circumscribed, 6 cm renal mass containing a solid nodule of 1.5 cm. Partial nephrectomy was performed. The tumour was characterized by monomorphic spindle cells and cysts lined by trapped «hobnail» epithelial cells. Sections showed focal infiltration of perinephric fat surrounding the solid nodule. Spindle cells expressed CD99, BCL2, EMA and SMA and were negative for S-100, CD34, oestrogen and progesterone receptors, desmin and WT1. The “hobnail epithelium” expressed CD10, PAX8, PAX2, EMA, CKAE1-AE3, CK7 and CK19, confirming its non-neoplastic and renal identity. FISH was performed and t(X;18) translocation, specific of SS, was demonstrated. The patient received 4 cycles of adjuvant chemotherapy and is alive without evidence of disease 9 months after surgery.