Chromogranin as a marker of neuroendocrine cells in cytologic material--an immunocytochemical study.

Cytologic material, including fine-needle aspirations, bronchial brushings, body cavity fluids, and tissue imprints from 39 neuroendocrine and 26 nonneuroendocrine tumors, was stained for chromogranin by the immunoperoxidase technic. Our results suggest that chromogranin is useful in identifying primary as well as metastatic neuroendocrine lesions from a variety of body sites. All lymphoid proliferations and carcinomas, including small-cell anaplastic carcinomas of the lung (oat-cell carcinomas), were negative. Chromogranin appears to be a useful marker in diagnostic cytology. This technic can be applied to routinely prepared cytologic material.