An immortalized cell culture from a malignant mixed tumor of the lacrimal gland.

Tumor cells from a malignant mixed tumor of the lacrimal gland were maintained in tissue culture for more than 55 generations. Comparative immunohistochemical analysis was performed on whole tumor sections and on the tumor cell culture to define the origin of the cells in culture. The cultured cells expressed cytokeratin, smooth-muscle actin, S-100 protein, and vimentin and were negative for glial fibrillary acidic protein. Tumor sections expressed cytokeratin but were negative for muscle-specific actin, vimentin, and glial fibrillary acidic protein. Through tissue culture studies of salivary gland epithelial neoplasias, which are very similar to lacrimal gland epithelial neoplasias, pluripotential stem cells have been identified. Similar tissue culture analysis of lacrimal gland epithelial neoplasms can be a valuable tool for studying the origin of these uncommon tumors.