Case Report: Adenocarcinoma of the Lacrimal Gland Presenting as an Abduction Deficit.

SIGNIFICANCE: It is imperative to follow the clinical guidelines for abduction deficits to ensure prompt diagnosis of potentially serious etiologies and monitor only those in which a microvascular etiology is most likely. This case reports highlights a rare diagnosis of a malignant tumor of the lacrimal gland presenting as an abduction deficit.

PURPOSE: Tumors of the lacrimal gland can cause abduction deficits, which may mimic an abducens nerve palsy. Abducens nerve palsies are often encountered by optometrists. This case report highlights the appropriate workup of an abduction deficit and reviews the literature of adenocarcinoma not otherwise specified.

CASE REPORT: A 67-year-old white man was transferred to the optometry clinic with a presumed ischemic abducens palsy. He was found to have an isolated left abduction deficit without vascular risk factors that prompted neuroimaging revealing a mass of the lacrimal gland. After an en bloc resection, a diagnosis of adenocarcinoma not otherwise specified was made. The patient underwent aggressive surgical exenteration followed by radiation.

CONCLUSIONS: Using the guidelines for evaluation of an abduction deficit, this serious malignancy was diagnosed. An adenocarcinoma not otherwise specified of the lacrimal gland is rare, and there are limited data on its clinical course, prognosis, and treatment. Recurrence and metastases occur at high rates; therefore, prompt diagnosis and aggressive intervention are crucial.