Identification of oncocytic lesions of salivary glands by anti-mitochondrial immunohistochemistry.

AIMS: To evaluate the immunohistochemistry using an anti-mitochondria antibody in the investigation of various oncocytic lesions of the salivary glands.

METHODS AND

RESULTS

Ten cases of adenolymphoma (Warthin's tumour) and one case each of benign oncocytoma and oncocytic carcinoma of the salivary glands were examined. Normal salivary glands were also tested. They were investigated immunohistochemically using mouse monoclonal antibody against human mitochondria. In normal salivary glands, epithelial cells of the striated ducts showed a thick linear immunoreactivity, which corresponded well to the intracytoplasmic distribution pattern of mitochondria. In addition, a small number of swollen epithelial cells showing an intense, finely granular immunoreactivity in the cytoplasm were scattered in the ductal system and acini ('oncocytic metaplasia'). Almost all neoplastic cells involved in adenolymphoma, benign oncocytoma, and oncocytic carcinoma showed an intense, finely granular immunoreactivity in the cytoplasm.

CONCLUSIONS

Immunohistochemistry using the anti-mitochondria antibody proved to be a highly sensitive and specific method for light microscopic identification of mitochondria and superior to routine H & E or PTAH stain especially in the detection of isolated oncocytic cells.