The CT and PET/CT manifestations of primary pulmonary adenoid cystic carcinoma

Objective: To investigate The CT and PET/CT features of primary pulmonary adenoid cystic carcinoma. Methods: CT findings of 17 patients (with PET/CT findings of 5 cases) pathologically proven with primary pulmonary adenoid cystic carcinoma were analyzed retrospectively. Results: It was classified to central type (n = 15), peripheral type (n = 2). Of the 15 cases of central type of ACC, there were intraluminal (2 cases), intra- and extraluminal extension (9 cases), and infiltrative wall thickening (4 cases) lesions. The peripheral type manifested as lobulated, without specula. Except the infiltrative wall thickening lesions, all of them appeared as homogenous low or moderately density with smooth margin on plain CT and slightly or moderately enhancement on contrast enhanced CT scan. Necrosis was found in 2 cases. The maximum SUV of tumors ranged from 2.5 to 8.7 (5.96 ± 2.38). Obstructive pneumonia and atelectasis were found in 8 cases, mediastinum and hilum lymph node metastasis were found in 4 cases, intrapulmonary metastasis in 1 case. Conclusion: The primary pulmonary adenoid cystic carcinoma is a rare tumor arise in lung, its CT manifestations have some characteristic, most of them manifested as intra-and extraluminal extension or infiltrative wall thickening lesions. Therefore, helical CT with multiplanar reconstructions provides precise information about the sizes, the growth patterns and the extent of the tumor, which is important for the diagnosis and treatment. (authors)