Small cell carcinoma versus other lung malignancies - Diagnosis by fine-needle aspiration cytology

BACKGROUND. When a diagnosis of small cell carcinoma is reached in a patien t with a lung mass, a surgical treatment approach is no longer considered a nd chemotherapy becomes the treatment of choice. The aim of this study is t o compare the diagnostic accuracy of fine-needle aspiration cytology in the diagnosis of small cell carcinoma with the diagnoses of other lung maligna ncies. The capacity of this technique to distinguish between these two cate gories is assessed. METHODS. Two hundred fifty-nine consecutive transthoracic fine needle aspir ations of lung tissue from 235 patients with histologic diagnosis of malign ancy were reviewed. The aspirates were performed over a 10-year period at t he University of Miami/Jackson Memorial Medical Center, Miami, Florida. Two hundred and forty-two fine-needle aspirations from 221 patients yielded sa tisfactory smears and were included in the study. Fourteen patients were ex cluded. The cytologic diagnoses were classified into 5 categories: 1) small cell carcinoma (18 smears, 7%); 2) other lung malignancies (158 smears, 65 %); 3) suspicious for malignancy (19 smears, 8%); 4) inflammatory process ( 7 smears, 3%); and 5) negative for malignancy (40 smears, 17%). RESULTS. The histologic diagnoses were divided into two groups: small cell carcinomas (29 smears, 12%), and other lung malignancies (213 smears, 88%). The efficiency of fine-needle aspiration cytology in the diagnosis of thes e two groups was 96% versus 88%, respectively, with an equal specificity of 100%, and a sensitivity of 67% versus 81%. Once the diagnosis of malignanc y was established, fine-needle aspiration cytology was found to be highly a ccurate in distinguishing small cell carcinoma from other neoplasms. CONCLUSION. We conclude that fine-needle aspiration cytology of the lung is an accurate diagnostic tool for the diagnosis of lung malignancies and is an excellent technique for distinguishing small cell carcinoma from other m alignant neoplasms. It can be used with confidence to select treatment moda lities and to avoid unnecessary surgeries in patients with lung malignancie s. Cancer (Cancer Cytopathol) 2000;90:279-85. (C) 2000 American Cancer Soci ety.