Alveolar adenoma is an isolated, well-defined peripheral lung tumor that originates from type II alveolar cells. The tumor consists of a network of simple, low-cubic, epithelium-coated lacunae with varying amounts of fine and inconspicuous-to-thick spindle cells that sometimes contain mucus sample matrix. Few cases of alveolar adenoma have been reported. These tumors are usually detected by imaging examinations where the alveolar adenoma typically presents as a peripheral, solitary cystic nodule in the lung. The presentation may mimic that of other types of lung tumors, consequently leading to difficulties in the differential diagnosis of this condition. Thus, accurate diagnosis of alveolar adenoma is based on a combination of pathological sections and immunohistochemistry. This study describes an alveolar adenoma in a 59-year-old female patient. Chest X-ray imaging and chest computed tomography identified malignant lesions in the right upper lobe. The patient subsequently underwent a thoracoscopic right upper lobectomy. The diagnosis of alveolar adenoma was confirmed after pathological examination of the excised postoperative tissue. The disease course was stable, and there was no recurrence of pulmonary lesions during 3 years of postoperative patient follow-up. Herein, we report the case of a patient with benign alveolar adenoma with poor imaging and pathological results.
Keywords: Alveolar adenoma; benign; peripheral lung tumor; poor imaging; pulmonary lesions; pulmonary nodules.