Fine-needle aspiration findings in idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (IRF) is an inflammatory and fibrosing process that can be complicated by periureteral encasement, ureteral obstru ction, and subsequent renal failure if left untreated. Unfortunately treatm ent is often delayed die to the nonspecific nature of the presenting signs and symptoms. Clinical, radiologic, and microscopic findings in IRF, if exa mined independently are all nonspecific for its diagnosis. Rendering a diag nosis of IRF by fine-needle aspiration (FNA) requires supportive clinical a nd radiologic data and systematic evaluation of entities in the differentia l diagnosis. Herein we report 2 cases of IRF diagnosed by FNA with subsequent histologic confirmation. Smears prepared from the aspirates revealed a combination of inflammatory cells and fibrous tissue. The inflammatory: component was com prised of a mixture of lymphocytes, plasma cells, and rare eosinophils and mast cells. These 2 cases represent, to our knowledge, only the second repo rt of IRF diagnosed by FNA. (C) 1999 Wiley-Liss, Inc.