Whipple's disease involving the mesenteric lymph nodes diagnosed by fine-needle aspiration.

Although it traditionally presents with signs and symptoms of small intestine involvement, such as diarrhea and malabsorption, Whipple's disease (WD) can involve many other organs. Typically, WD diagnosis is established by biopsy of the small intestine. A case of WD, established by duodenal biopsy, in a 36-yr-old male is presented. This patient developed mesenteric lymphadenopathy, prompting computerized-tomography guided fine-needle aspiration (FNA), which showed typical features of WD. Electron microscopy (EM) studies confirmed the diagnosis. To our knowledge, this is the first reported case of lymph-node involvement in WD diagnosed by FNA biopsy.