title: Features of benign granular cell tumor on fine needle aspiration.
abstract: OBJECTIVE
  To describe the cytomorphologic features of benign granular cell tumor (GCT) on fine needle aspiration (FNA) biopsy and discuss the differential diagnosis.
  
  
  METHODS
  We reviewed three fine needle aspirates of surgically confirmed benign GCT. Immunocytochemical staining for S-100 was performed on the aspirate smear in one case.
  
  
  RESULTS
  Two GCT were thigh lesions, where lipoma and fibromatosis were the leading clinical diagnosis, and the third was a breast mass clinically suspected to be a fibroadenoma. All FNA specimens were highly cellular and composed of fairly uniform cells with eccentric, round-to-slightly oval nuclei and abundant, finely granular cytoplasm. The cells were fragile, with stripped nuclei in a background of finely granular material. Occasional cells with nuclear pleomorphism and small-but-conspicuous nucleoli were identified. There was no evidence of necrosis or mitotic activity. Rare intranuclear cytoplasmic inclusions were identified in two cases. The granular cells were immunoreactive for S-100 in the case studied.
  
  
  CONCLUSIONS
  Benign GCT has a distinctive cytomorphologic appearance that permits its diagnosis on FNA. High cellularity, occasional cells with nuclear pleomorphism and prominent nucleoli are features that can be present in benign GCT. Mitotic figures and necrosis should be identified before a diagnosis of malignancy is rendered.
authors.affiliation: Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: K
authors.initials: K
authors.lastname: Liu
authors.forename: J F
authors.initials: JF
authors.lastname: Madden
authors.forename: B A
authors.initials: BA
authors.lastname: Olatidoye
authors.forename: L G
authors.initials: LG
authors.lastname: Dodd
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D016586:Granular Cell Tumor / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D012983:Soft Tissue Neoplasms / Q000473:pathology*