Adenoid cystic carcinoma of the labium oris with rare metastasis to the pleural cavity.

A 57-year-old Southeast Asian woman with a remote history of adenoid cystic carcinoma (ACC) of the right labium superius oris (upper lip) presented to the hospital with vague epigastric pain. On workup, she was found to have multiple pleural nodules. Histopathology confirmed the diagnosis of metastatic ACC. After 8 months of active surveillance, evidence of disease progression was found and the patient was started on pembrolizumab. Follow-up after starting pembrolizumab showed stable disease with no significant side effects.