title: Fine needle aspiration cytology of carcinoid tumors.
abstract: OBJECTIVE
  To define the cytomorphologic features of carcinoid tumor.
  
  
  METHODS
  The study consisted of 19 carcinoid tumors sampled by fine needle aspiration. These included 6 pulmonary carcinoids. 11 intestinal carcinoids and 2 aspirates from a patient with a mediastinal carcinoid. The cytomorphologic features of carcinoid tumor were documented, and, in selected cases, immunocytochemical findings were noted. Additionally, the cytology literature concerning carcinoid tumor was reviewed and summarized.
  
  
  RESULTS
  Morphologically, the carcinoid tumors consisted predominantly of loose groups with a background of single cells. A striking degree of cellular and nuclear monomorphism was seen in all cases. Nuclei were small and round to oval, and all exhibited a characteristic finely granular, evenly distributed chromatin pattern. Cytoplasm was minimal to moderate in amount and finely granular in appearance. Necrosis and prominent nucleoli were not seen. Positive staining was noted in all seven cases in which immunostaining for chromogranin was performed. Neuron-specific enolase was positive in four of five cases.
  
  
  CONCLUSIONS
  The cytomorphologic characteristics of carcinoid tumors are distinctive, and appropriate ancillary studies can assist in confirming the diagnosis.
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, USA.
authors.forename: B T
authors.initials: BT
authors.lastname: Collins
authors.forename: H M
authors.initials: HM
authors.lastname: Cramer
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle / Q000379:methods; D002276:Carcinoid Tumor / Q000473:pathology*; D002466:Cell Nucleolus / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D002843:Chromatin / Q000473:pathology; D003593:Cytoplasm / Q000473:pathology; D005260:Female; D006801:Humans; D007414:Intestinal Neoplasms / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008175:Lung Neoplasms / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008479:Mediastinal Neoplasms / Q000473:pathology*; D008875:Middle Aged; D012186:Retroperitoneal Neoplasms / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D002843:Chromatin