Pulmonary neuroendocrine tumors: Study of 90 cases focusing on clinicopathological characteristics, immunophenotype, preoperative biopsy, and frozen section diagnoses

Abstract

Pulmonary neuroendocrine tumors have a prognostic spectrum including typical carcinoid (TC), atypical carcinoid (AC), small cell carcinoma (SCLC), and large cell neuroendocrine carcinoma (LCNEC). We conducted a retrospective study to compare their clinicopathological characteristics, immunophenotype, preoperative biopsy and frozen section diagnoses, and prognosis. Ninety cases of surgically treated pulmonary neuroendocrine tumors were studied. Immunohistochemical studies were performed using antibodies to chromogranin A, synaptophysin, and CD56. The preoperative biopsy and frozen section diagnoses were reviewed. The 5-year survival rates for TC, AC, SCLC, and LCNEC were 96.6%, 66.7%, 42.4%, and 38.0%, respectively. T stage and pleural status correlated with outcome of SCLC and LCNEC, but N-stage and overall TNM stage did not. In preoperative biopsy, accurate diagnosis was achieved in 5 of 11 TC, 2 of 4 AC, 6 of 15 SCLC, and 0 of 5 LCNEC cases. Using frozen sections, accurate diagnosis was achieved in 8 of 12 TC, 2 of 11 SCLC, and 0 of 11 LCNEC cases. LCNEC was the most difficult to diagnose using either preoperative biopsy or frozen sections. T stage and pleural status can predict outcome of SCLC and LCNEC.