Alveolar adenoma combined with multifocal cysts: case report and literature review.

Alveolar adenoma is an extremely rare and benign pulmonary neoplasm; it is always asymptomatic and is usually detected incidentally on routine chest X-radiography. Typically on imaging examinations, alveolar adenoma exhibits as a peripheral, solitary, cystic nodule in the lung, which may easily imitate other lung lesions, consequently leading to difficulties in the differential diagnosis of this condition. Surgical resection is the primary treatment option. The diagnosis of alveolar adenoma is mainly based on postoperative histopathology, with features of proliferative type 2 alveolar epithelial cells and septal mesenchyme. The present case was a 60-year-old woman with alveolar adenoma, combined with systemic mutifocal cystic lesions. She underwent surgery following the obvious enlargement of this mass and a cystic nodule 7 cm in maximum diameter was resected. Postoperative histopathology confirmed a diagnosis of alveolar adenoma; her prognosis was favourable. In addition to reporting a rare case of alveolar adenoma coexisting with multifocal cysts, the English-language literature was reviewed for similar cases of alveolar adenoma.