This case report details an unusual presentation of primary adenoid cystic carcinoma (ACC) of the lung in a 50-year-old male patient. The patient presented with a large cystic mass occupying the entire left hemithorax, diagnosed via imaging and biopsy. The tumor's size and radiological appearance are uncommon, and the review of existing literature highlights the challenges in diagnosis and treatment of this rare malignancy. The patient's advanced stage (T4N3M1a) necessitated palliative chemotherapy.
