Primary adenoid cystic carcinoma of the lung: A case report and literature review

Primary adenoid cystic carcinoma (ACC) of the lung is an unusual thoracic neoplasm with slow growing and low-grade malignancy. Usually, it is diagnosed at a higher clinical stage and is difficult to resect due to its central location. Herein, we report a 56-year-old man with hemoptysis associated with dyspnea and weight loss lasting for one month. Bronchial fibroscopy highlighted a budding nodular tumor in the left main bronchus. The patient underwent a left pneumonectomy with mediastinal lymphadenomectomy. Microscopic examination showed tumor cells infiltrating the bronchial wall and the cartilage and concluded to an ACC of the left bronchus. Ear, nose, and throat examination as well as cervico-facial magnetic resonance imaging were performed to search a primary salivary gland tumor and were returned without abnormalities. The tumor was classified as a primary ACC of the left bronchus without lymph node metastasis. To avoid their misdiagnosis, ACCs of the lung should be well known by the pathologist and surgeons. Their pathological features may be misleading and referring to a benign lesion, however, the presence of cribriform foci and infiltrative pattern are very suggestive. Although, indolent and slow growing tumor, long-term recurrences are quite frequent, especially in case of unclear surgical margin.