Dacryoadenoma. A unique tumor of the conjunctival epithelium.

For 15 years, a 48-year-old woman had been aware of a pinkish translucent inferior epibulbar mass toward the fornix that was stationary in size. Light microscopic evaluation of the excised specimen showed that it was a gland-forming benign tumor. It originated from the surface epithelium by the downward invagination of tubular formations that underwent secondary and tertiary ramifications. The surface epithelium overlying the mass was not normal conjunctival squamous epithelium, but it was a modification in the form of a superficial layer of columnar to cuboidal cells surmounting several nuclei similar to the cells lining the subepithelial lumen-forming units. Electron microscopy showed that both the surface and tumor epithelium contained apical lacrimal-type zymogen granules and basilar whorls of rough-surfaced endoplasmic reticulum. Scattered myoepithelial cells were associated with the acinar-type epithelium of the tumor, and there were goblet cells intermixed. Neither light nor electron microscopy disclosed the presence of true ducts. The authors conclude that the lesion was a benign proliferation of lacrimal secretory-type cells and suggest the term "dacryoadenoma" for this previously undescribed entity.