Immunocytochemical Evaluation of Large Cell Neuroendocrine Carcinoma of the Lung

OBJECTIVE To examine whether immunocytochemistry can distinguish pulmonary large cell neuroendocrine carcinoma (LCNEC) among non-small cell lung cancers (NSCLCs). STUDY DESIGN Tumor touch imprint cytologic specimens of 109 lung cancers were studied. Immunocytochemistry was done using a total of 8 primary antibodies: chromogranin A, synaptophysin, neural cell adhesion molecule, neuron specific enolase, CK34betaE12, thyroid transcription factor-1, cytokeratin 18 and E-cadherin. RESULTS If 2 or 3 antibodies of chromogranin A, synaptophysin and neural cell adhesion molecule were stained positive and CK34betaE12 was not stained, pulmonary LCNEC can be selected accurately among other NSCLCs with 100% sensitivity and 100% specificity. CONCLUSION This study reveals that immunocytochemistry can help distinguish LCNEC of the lung from other NSCLCs.