Bronchial granular-cell tumor. Report of a case with preoperative cytologic diagnosis on bronchial brushings and immunohistochemical studies.

A 42-year-old man presented with a polypoid endobronchial mass of the right apical segmental bronchus. Bronchial brushing smears contained clusters of cells exhibiting abundant diffusely granular cytoplasm with indistinct borders. A cytologic diagnosis of granular-cell tumor was rendered. Histologic examination of the upper right lobectomy specimen provided confirmation. Immunohistochemically, the granular cells strongly reacted with the S-100 protein antibody. This case demonstrates that the cytologic diagnosis of bronchial granular-cell tumor is possible if this lesion is considered in the differential diagnosis of lung tumors.