Primary acinic cell carcinoma of the lung with psammoma bodies: A case report and review of literature

Salivary gland-type tumors are rare in the lung. Primary acinic cell carcinoma of the lung is extremely rare. Here, we report a case of primary acinic cell carcinoma of the lung with prominent psammoma bodies. A 31-year-old man came to our hospital with a tumor in the basal segment of the lower lobe of the right lung. The tumor tissue displayed solid, acinar, or microcystic structures at different regions. A large amount of psammoma bodies were scattered in more than half of the tumor. The majority of the tumor cells were round or polygonal in shape, with abundant acidophilic granular or vacuolated cytoplasm. The results of tumor tissue tests were positive for periodic acid Schiff (PAS), broad-spectrum cytokeratin, and cytokeratin 7 staining, but negative for P63, TTF-1, CD56, synaptophysin, HMB45, and PR staining. Based on the clinical information, histological features, and the immunohistochemical staining profile, the tumor was diagnosed as a primary acinic cell carcinoma of the lung. This is the first report of primary acinic cell carcinoma with prominent psammoma bodies in the lung.