Typical and Atypical Pulmonary Carcinoid Tumor Overdiagnosed as Small-Cell Carcinoma on Biopsy Specimens

• DOI: 10.1097/01.pas.0000149690.75462.29
• Publication Date: 2005-01-11T09:01:09Z
• Authors: Giuseppe Pelosi; Jaime Rodriguez; Giuseppe Viale; Juan Rosai
• Keywords: Chromogranin A; Synaptophysin; Proliferation index

Seven patients with typical or atypical pulmonary carcinoid tumors overdiagnosed as small-cell carcinoma on bronchoscopic biopsies are described. Bronchial from 9 consecutive lung were used control group for histologic and immunohistochemical studies (cytokeratins, chromogranin A, synaptophysin, Ki-67 [MIB-1], TTF-1). The presented either central peripheral lesions composed of tumor cells granular, sometimes coarse chromatin pattern, high levels A/synaptophysin immunoreactivity, low (<20%) (MIB-1) labeling index. stroma contained thin-walled blood vessels. Small-cell carcinomas always showed location, finely dispersed nuclear chromatin, lower A/synaptophysin, (>50%) thick-walled vessels glomeruloid configuration. Judging this study, overdiagnosis in small crushed bronchial remains a significant potential problem worldwide sample hospital settings. Careful evaluation hematoxylin eosin sections the most important tool differential diagnosis, cell proliferation by index emerging our review useful ancillary technique distinction.