Unusual findings on fine-needle aspiration cytology of a retroperitoneal mass.

Abstract

A 77-year-old male presented with intermittent abdominal pain. CT scan revealed a 4.7 cm retroperitoneal mass. A subsequent fine-needle aspiration (FNA)with a core biopsy revealed basophilic clumps of acellular homogenous material on Diff Quik stains performed during rapid on site evaluation [Figure 1a]. Pap stain showed greenish round deposits [Figure 1b]