A Rare Presentation of Alveolar Soft Part Sarcoma in the Bladder.

Alveolar soft part sarcoma (ASPS) is a rare and distinctive subtype of soft tissue sarcoma accounting for <1% of all sarcomas. Characterized by the t(X;17)(p11;q25) translocation, it typically affects the extremities in younger individuals. This case report presents a bladder ASPS in a 45-year-old woman, a rare occurrence, developing as a second primary malignancy following breast cancer treatment. Histopathological analysis, immunohistochemistry and molecular diagnostics confirmed the diagnosis. The patient underwent partial cystectomy with clear surgical margins and remained recurrence-free 38 months post-resection. This report highlights the diagnostic challenges, therapeutic strategies, and the importance of long-term surveillance for bladder ASPS.