CT imaging features of bronchiolar adenoma / 中华放射学杂志

ABSTRACT

Objective:To investigate the CT characteristics of bronchiolar adenoma (BA) in order to improve the understanding of the disease and to increase the accuracy of preoperative diagnosis.Methods:The clinical, imaging and pathological data of 69 patients with BA confirmed by surgical resection and pathology at Cancer Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences from December 2018 to November 2020 were retrospectively reviewed. The type, the location and the size of the lesions, the distance from the lesion to the adjacent pleura, as well as the morphological characteristics including lobulation, spiculation, bubble lucency and pleural indentation were analyzed and recorded. The follow-up CT data were also reviewed.Results:Among 69 BAs, pre-operation chest CT displayed visible lesion in 25 cases, and showed negative in 44 cases. According to the lesion density, the 25 BAs on CT images were classified into solid type ( n=8), ground-glass type ( n=8), cystic type ( n=6) and cyst type ( n=3). There were 15 lesions in the right lung (1 in the upper, 2 in the middle and 12 in the lower lobe) and 10 lesions in the left lung (5 in the upper and 5 in the lower lobe). Ten lesions were found adjacent to the pleura. As for the other 15 cases, the distance between the lesion and the adjacent pleura was (10±7) mm. Calcification was displayed in one cystic type BA case. The maximum diameter of 25 BAs were 4.4-30.3 mm, with the median value of 9.6 mm. The lobulation, spiculation, bubble lucency, and pleural indentation of lesions were detected in 20, 11, 12, and 6 cases. In total there were 11 patients received the preoperative follow-up CT, and 4 cases showed enlargement in diameter (including 2 cases of solid type, 1 of ground-glass type and 1 of cystic type). The growth rate was 0.43-2.14 mm/year, with the median value of 1.67 mm/year. Imaging signs including spiculation ( n=1), bubble lucency ( n=1) and lobulation ( n=1) were newly discovered on the preoperative follow-up CT. Postoperative follow-up CT was performed in 13 cases, without any recurrence or metastasis found. Conclusions:CT imaging features of BA usually display as a single pulmonary solid or ground-glass nodule, and also can be presented as cystic or cyst type in several cases. Lesions can appear the lobulation, spiculation and bubble lucency, with calcification rarely found. A few of BA cases can enlarge during follow-up.