Primary retroperitoneal perivascular epithelioid cell neoplasm: A case report.

Perivascular epithelioid cell neoplasm (PEComa) is a rare type of tumor, and primary retroperitoneal PEComa is rarer still. The present report discusses the case of a 51-year-old woman who was admitted to hospital following stiffness and discomfort in the upper right abdomen for longer than one month. Computed tomography identified a soft tissue mass in the rear right kidney, accompanied by clear cystic degeneration and bleeding. The borderline between the mass and the right kidney was not distinct. An enhanced scan revealed that the solid section of the mass was progressively enhanced. Following excision of the mass and the affected right kidney, the patient was pathologically diagnosed with retroperitoneal PEComa involving the right kidney. Short-term reexamination did not detect any recurrence.