Adenocarcinoma, Not Otherwise Specified, Arising in Accessory Lacrimal Gland: A Diagnostic Challenge.

Neoplasms arising in accessory lacrimal glands are rare. We describe a 33-year-old man with adenocarcinoma arising in the left lower eyelid accessory lacrimal gland. Microscopic evaluation demonstrated an infiltrative neoplasm composed of mildly to moderately pleomorphic cells with abundant eosinophilic cytoplasm and focal intracytoplasmic vacuoles, arranged predominantly in ductules. Foci of luminal and intracytoplasmic eosinophilic secretory material and occasional mucin were noted. An in situ component was identified in the gland of Wolfring. Though perineural invasion was present, high-grade nuclear features, brisk mitotic activity, and comedonecrosis were not identified. Immunohistochemical studies were notable for immunoreactivity of the tumor cells for CK7, carcinoembryonic antigen, BRST-2, androgen receptors, and HER2/neu (2+). The neoplastic cells were negative for CK20, estrogen and progesterone receptors, S-100, p63, calponin, thyroid transcription factor-1, and prostate-specific antigen. Fluorescence in situ hybridization studies for ETV6 and MAML2 rearrangements and for HER2/neu amplification were negative. Because of the absence of unifying morphologic, immunophenotypic, and molecular genetic findings, the diagnosis of adenocarcinoma, not otherwise specified, was rendered. The patient underwent comprehensive oncologic workup, which was negative for another primary tumor and metastases. He remains disease free with a follow-up of 4 years. This case illustrates the challenges encountered in applying salivary gland tumor classification to the accessory lacrimal gland neoplasm.