Ocular Microcystic Adnexal Carcinoma With High-Grade Features: A Case Report With Orbital Exenteration.

An 81-year-old man with a history of multiple skin cancers presented with a change to a longstanding lesion. Biopsy confirmed microcystic adnexal carcinoma. The lesion was excised with clear margins. Over the course of 5 years, the tumor recurred four times in the periorbital and orbital area. Histopathology showed progressively poorer differentiation, with increasing mitotic activity and decreasing ductular differentiation. Next-generation sequencing testing demonstrated a Tier III variant of unknown significance in ARID1A and was otherwise negative for gene mutations and fusions in a panel of 141 cancer-related genes. Orbital invasion necessitated exenteration 5 years after initial presentation and adjuvant radiation was used to decrease the risk of recurrence. The patient subsequently experienced metastasis to the parotid and regional lymph nodes. Seven and a half years after initial presentation, the patient is clear of disease and on regular follow-up.