Bronchiolar adenoma with diffuse pulmonary nodules: a extremely rare case report and review of literature

Background Bronchiolar adenoma(BA) is a recently recognized, rare tumor of the bronchioles. It can be divided into proximal and distal types according to the proportion of mucinous and ciliated cells on the luminal surface. BA is often misdiagnosed because it has similar ultrasonographic, gross and histological presentations as other diseases. Here, we report a rare case of BA characterized by many fused nodules. Case presentation A 68-year-old woman attended the Tianjin Taida Hospital surgical Clinic mainly because of "intermittent cough for >1 month". Chest computed tomography (CT) showed multiple solid nodules in the upper and lower left lung. The nodules had irregular outlines, with a maximum diameter of 65 mm. A double needle lung biopsy specimen was removed guided by ultrasound under local anesthesia. Histologically, the biopsy specimen was finally diagnosed as the distal type of BA. Conclusion BA with diffuse pulmonary nodules is rare. Diagnosis of BA needs comprehensive analysis of imaging, gross specimen analysis, histopathology, and immunohistochemical staining to make a correct diagnosis and avoid misdiagnosis. There are few studies on prognosis, which needs close follow-up and more data accumulation.