Computed Tomography Findings and Preliminary Exploration of Pathological Analysis of Bronchiolar Adenoma

Objective: To summarize and analyze the clinical data, computed tomography (CT) signs, and pathological features of bronchiolar adenoma, and to discuss the diagnostic value of bronchiolar adenoma. Methods: In total, 18 cases of pulmonary nodules diagnosed as bronchiolar adenoma via postoperative pathology from January 2020 to December 2020 were retrospectively collected, and the clinical data, chest CT signs, and postoperative pathological features of pulmonary nodules were analyzed. Results: Among the 18 cases, 16 had no clinical chest symptoms, and 2 had chest pain. The patients were 18~65 years old. The mean age was 51.8 years, and the median age (25％~75％ quantile) was 52 (49~59) years; 7 patients were male (39％), and 11 were females (61％). The average maximum slice diameter of bronchiolar adenoma was 11.1 mm, and the median diameter (25％~75％ quantile) was 8 (6~15) mm. There were 15 cases with lesion distance ≤10 mm from the pleura. CT showed that 8 cases were pure ground-glass nodules (pGGN), 7 cases were part-solid nodules (PSN), and 3 cases had simple cystic space. The mean CT value of bronchiolar adenomas presenting with pGGN was −690.7 HU. The median mean CT value (25％~75％ quantiles) was −717.5 (−722~ −681) HU. A spicule sign at the nodular margin was found in 6 of the 18 cases. Pleural traction around nodules was found in 7 cases, and bronchiectasis occurred in nodules in 5 cases. The postoperative gross pathological diameter of 18 nodules was 9.1 mm, and the median diameter (25％~75％ quantile) was 7 (6~9) mm. Pathological immunohistochemical antibody CK7 was positive in 18 cases; p40, p63, CK5/6, and TTF-1 were positive in 16 cases. Conclusions: Bronchiolar adenoma often occurs in middle-aged and older women. Preoperative CT diagnosis of subpleural nodules around 10 mm could indicate the disease, and immunohistochemical antibody CK7, p40, and other indicators are qualitative methods for diagnosing bronchiolar adenoma.