Cytodiagnosis of intracranial metastatic adenoid cystic carcinoma: Spread from a primary tumor in the lacrimal gland.

Adenoid cystic carcinoma (ACC) of the lacrimal gland is a rarely encountered orbital tumor. It invades intracranially more frequently than carcinomas of other glands in the head and neck. A 61-year-old man underwent right orbital exenteration for a tumor in the supraorbital region. He had lost all records and presented to us with a diffuse swelling in the right forehead, six years later. Fine-needle aspiration cytology of the right frontal swelling revealed monomorphic population of small, slightly atypical cells, arranged in multilayered groups with abundant fine intercellular metachromatic substance between cell groups. There were hyaline globules of varying size with attached tumor cells. Cytological diagnosis of metastatic intracranial ACC with a lacrimal gland primary was suggested. Biopsy of the swelling confirmed our cytological diagnosis of ACC with perineural, vascular and lymphatic invasion. Thus, the authors report this case of intracranial metastasis of ACC of the lacrimal gland to remind neurosurgeons planning intervention that this disease shows a tendency to invade intracranially.