Renal angiomyolipoma, a diagnostic dilemma: a case report.

Angiomyolipomas are the most common benign mesenchymal tumours of the kidney. Most of the angiomyolipomas in adults are asymptomatic and discovered incidentally. We report a case in a symptomatic 55 yrs old male who had a huge retroperitoneal mass abdomen and in whom diagnosis and organ of origin remained unclear until operation and histopathological study was performed. Radiological and fine needle aspiration cytology (FNAC) report of a malignant retroperitoneal tumour was given, but histological examination of the respective tumorous mass showed a benign renal tumour - angiomyolipoma. Our emphasis by reporting this case is to make cytopathologists and radiologists aware of such kind of diagnostic pitfall encountered while reporting retroperitoneal masses.