Horseshoe kidney presenting as a retroperitoneal mass - Report of a case diagnosed by fine needle aspiration cytology

BACKGROUND: Horseshoe kidney is a renal congenital anomaly. It is the resul t of the fusion of either upper or lower poles of both kidneys, appearing a s a horseshoe-shaped structure. This anomaly is very frequent: it can be fo und in about 1 of every 50-1,000 autopsies). CASE: Computed tomography performed routinely after pancreatitis in a 37-ye ar-old female showed a retroperitoneal mass of uncertain origin. Fine needl e aspiration cytology (FNAC) smears evidenced normal renal tissue. Urograph y confirmed the diagnosis of horseshoe kidney. CONCLUSION: This is the first reported case of house shoe kidney diagnosed by FNAC. If demonstrates the utility of FNAC for diagnosis of retroperitone al masses, especially if they are asymptomatic.