Hyalinizing Clear Cell Carcinoma of the Bronchus.

Hyalinizing clear cell carcinoma (HCCC) is an uncommon low-grade minor salivary gland neoplasm that usually arises in the head and neck region. We report a 55-year-old man who presented with a 2.5 cm lung mass that was partially obstructing the right bronchus intermedius. The tumor consisted of cords and nests of clear and eosinophilic cells in a hyalinized stromal background. The neoplastic cells expressed cytokeratin (CK) 7, CK 5/6, high-molecular weight cytokeratin (34BE12), p63 and p40, while TTF-1, napsin A, CK20, S100, smooth muscle actin, synaptophysin and chromogranin were negative. Mucicarmine stain also was negative in the lesional cells. Fluorescence in situ hybridization using break apart probes revealed rearrangement of the Ewing Sarcoma Breakpoint Region 1 gene locus. The morphologic, immunophenotypic and cytogenetic findings confirmed the diagnosis of HCCC, most likely of bronchial submucosal gland origin. To our knowledge, only two other reports of primary pulmonary HCCC are available in English literature.