Preoperative diagnosis of renal angiomyolipoma with fine needle aspiration cytology: a report of 3 cases

BACKGROUND: Angiomyolipoma is a rare benign neoplasm, commonly involving the kidney. Preoperative diagnosis on fine needle aspiration cytology can confirm the diagnosis, reducing the chances of unnecessary surgery. CASES: We studied cases of renal angiomyolipoma (AML) presenting within 1 year with palpable renal masses confirmed on ultrasound to be of renal origin. Fine needle aspiration cytology (FNAC) smears showed a few cohesive syncytial fragments with adipocytes, spindle cells and isolated single cells with foamy cytoplasm; a diagnosis of AML was made. The diagnosis was confirmed on histopathology, which showed mature adipose tissue, tortuous and thick-walled blood vessels lacking elastic tissue lamina and bundles of smooth muscles that seemed to emanate from the blood vessels. CONCLUSION: A preoperative diagnosis of renal AML is of great importance for correct management. In fact, when the lesion is small and asymptomatic, a conservative approach may be considered. Partial nephrectomy is possible with masses < 5 cm. Preoperative FNAC along with computed tomographic findings and immunocytochemical analysis of FNAC smears with HNB-45 can confirm the diagnosis of AML, thus preventing unindicated nephrectomy.