Multiloculated renal cyst

A rare benign renal tumor characterized by a typically unilateral, solitary, multiloculated cystic mass consisting of small, non-communicating cysts with flat, cuboidal, or hobnail epithelial lining, separated by fibrous septa which may have an ovarian stroma-like appearance or be paucicellular. The tumor is surrounded by a thick fibrous capsule and does not contain solid areas or necrosis. Patients may be asymptomatic or present with a palpable abdominal mass and/or abdominal or flank pain. Age distribution is bimodal, the typical age of onset being either below five or between 40 and 70 years of age.