ACINIC CELL-CARCINOMA OF THE LACRIMAL GLAND

An 18-year-old woman underwent exenteration of the right orbit for tum or recurrence 3 years subsequent to external-beam irradiation for a la crimal gland tumor diagnosed as an ''adenocarcinoma.'' Light microscop y of the exenteration specimen revealed an acinic cell carcinoma of th e lacrimal gland, with a predominant microcystic (latticelike) pattern of growth. Cytoplasmic vacuoles and the secretion within the microcys ts stained positive with periodic acid-Schiff with and without or-amyl ase, alcian blue (at a pH of 2.5), mucicarmine, and colloidal iron wit h and without hyaluronidase. This histochemical staining for epithelia l mucins supports the theory that the lacrimal gland, although serous in type, may also function as a modified mucus gland. There was cytopl asmic immunopositivity for keratin (CAM 5.2, KAE 1-3); immunostaining for vasoactive intestinal polypeptide was negative. Electron microscop y disclosed undifferentiated features of intercalated duct cells. We s peculate that the lack of immunoreactivity for vasoactive intestinal p olypeptide may be correlated with the predominantly undifferentiated i ntercalated duct cell features observed ultrastructurally.