title: Peripheral small-cell carcinoma of the lung resembling carcinoid tumor. A clinical and pathologic study of 14 cases.
abstract: We studied 14 small-cell, epithelial tumors of the lung with histologic features intermediate between typical carcinoid tumor and undifferentiated small-cell carcinoma. All of the tumors arose in the periphery of the lung beyond a segmental bronchus and were excised. Histologically, three of the tumors were low grade and 11 were high grade. The low-grade tumors had an organoid pattern comprising more than half of the area examined histologically, less than five mitoses per 10 high-power fields, individual cell necrosis, and nuclear pleomorphism of less than half of the cells. The high-grade tumors had the opposite characteristics. Distinction of these peripheral tumors from typical carcinoid tumors and from undifferentiated small-cell carcinomas is established after excision and cannot be made reliably on the findings of a transbronchial or needle biopsy. Prognosis was worse than that for typical carcinoid tumors but better than that for undifferentiated small-cell carcinomas.
authors.forename: E J
authors.initials: EJ
authors.lastname: Mark
authors.forename: J F
authors.initials: JF
authors.lastname: Ramirez
mesh_terms: D002276:Carcinoid Tumor / Q000473:pathology*; D018288:Carcinoma, Small Cell / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged