Bronchial granular cell tumor with osteopontin and osteonectin expression:A case report

The case of a 52-year-old Japanese man with bronchial granular cell tumors with osteopontin and osteonectin expression is reported here because there have been few investigations of their expression in benign tumors. He was a dmitted because of sudden hematemesis. A bronchoscopic examination revealed a lobulated polypoid tumor located in the left and right bronchi. Histolog ically, most tumor cells had abundant granular eosinophilic cytoplasm and w ere immunoreactive for S-100, neuron-specific enolase (NSE), CD68 and vimen tin. Moreover, osteopontin-positive tumor cells were randomly distributed i n the tumor tissue, but few stromal cells were positive. In contrast, osteo nectin was mainly expressed in the peripheral tumor cells and was also dist ributed in the stromal cells. Blood vessels at the tumor border in which os teonectin-positive tumor cells were distributed, proliferated moderately. T hese results suggest that osteopontin and osteonectin may play a role in th e progression of granular cell tumors and in the interaction between the tu mor and host or angiogenesis around the tumor, respectively.