Transurethral en bloc resection of a bladder perivascular epithelioid cell tumor (PEComa): a case report

Abstract

Background: Perivascular epithelioid cell tumor (PEComa) is a mesenchymal tumor with distinct histologic and immunologic features. PEComa originating in the bladder is extremely rare clinically, with only 35 cases reported in the English literature so far. We report the first case of bladder PEComa resection by transurethral en bloc resection of bladder tumor (ERBT). Case presentation: A 66-year-old woman presented to our hospital with an ultrasound finding of a slightly strong echogenic mass of about 1.5×1.3×1.3 cm in size on the posterior wall of the bladder. The patient did not have any clinical symptoms during the disease. The enhanced computed tomography and enhanced magnetic resonance imaging after admission both suggested a well-defined isolated nodular mass on the posterior wall of the bladder with significant enhancement on the enhanced scan. The tumor was successfully and completely resected by ERBT. Postoperative pathological examination and immunohistochemical results confirmed that the mass was bladder PEComa. No tumor recurrence was observed in the six-month postoperative follow-up. Conclusions: Bladder PEComa is an extremely rare mesenchymal tumor of the urinary system. When imaging and cystoscopy revealed a nodular mass with an abundant blood supply in the bladder, PEComa should be included in the differential diagnosis of bladder tumors. Surgical resection is currently the main option for the treatment of bladder PEComa. For solitary, with pedicle, narrow-basal, small-sized bladder PEComa, resection of the tumor by ERBT is safe and feasible.