title: Fine needle aspiration cytology of atypical carcinoid of the lung.
abstract: The cytologic features of eight atypical carcinoid tumors of the lung, as observed in fine needle aspiration (FNA) specimens, are described in detail. They were compared with 21 pulmonary squamous-cell carcinomas, 16 adenocarcinomas, 5 small-cell undifferentiated carcinomas, 3 large-cell undifferentiated carcinomas and 1 typical carcinoid tumor. Atypical carcinoid tumor was easily distinguished from the other pulmonary neoplasms in most instances. Only two poorly differentiated squamous-cell carcinomas (one of which had atypical carcinoid as a component) and one small-cell undifferentiated carcinoma had similar cytologic features. One atypical carcinoid also had cytologic features similar to small-cell undifferentiated carcinoma. Because atypical carcinoid and small-cell undifferentiated carcinoma, at times, may be difficult to separate in FNA specimens, surgical resection of all stage I neoplasms with cytologic features evocative of either neoplasm is recommended.
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002276:Carcinoid Tumor / Q000473:pathology*; D018288:Carcinoma, Small Cell / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged