Synchronous pure epithelioid angiomyolipoma of the kidney and retroperitoneal schwannoma in the same patient on 18F-FDG PET/CT imaging.

A 21-year-old woman was admitted to our hospital after incidental detection of a left renal lesion on ultrasound scan. Abdominal contrast-enhanced CT scan revealed a moderately enhanced lesion in the left kidney and a round mass with slight enhancement in the retroperitoneum. FDG PET/CT imaging was performed for whole-body survey, showing increased tracer accumulation in both the left renal and the retroperitoneal lesions. Left renal cell carcinoma with retroperitoneal metastasis was suspected. Synchronous pure epithelioid angiomyolipoma of the left kidney and retroperitoneal schwannoma were diagnosed by pathology. This case highlights that epithelioid angiomyolipoma should be considered as one of the differential diagnosis in renal lesions with increased FDG uptake.