Characteristics and diagnostic value of CT and MRI in adrenocortical carcinoma: a study of 39 cases

Objective: To analyze CT and MRI imaging features of adrenocortical carcinoma (ACC). Methods: A retrospective analysis was conducted on the CT, MRI plain and contrast-enhanced imaging manifestations and clinical data of 39 ACC patients,and all were confirmed by surgery and pathological examination. The imaging features with significant diagnostic value for ACC were summarized, and the value of two imaging techniques for the diagnosis of ACC was explored. Results: Fourteen patients underwent both CT and MRI plain and enhanced examinations, while 22 patients underwent CT plain and enhanced examinations, and 3 patients underwent MRI examination only. Among the 39 ACC patients, 38 tumors were unilateral (19 on the left and 19 on the right), and 1 tumor was bilateral; twenty-three cases of tumors were lobulated, while 16 cases were quasi circular; the diameter of the tumor ranged from 4.0 to 17.3 cm. In CT and MRI examinations, intralesional hemorrhage was found in 47.2% and 82.4% of cases; thickened and tortuous tumor vasculature were found in 91.7% and 50% of cases; irregular capsule was found in 77.8% and 82.4% of cases. All tumors showed heterogeneous enhancement, and most of the solid components of the tumor showed moderate enhancement; a small number of cases showed calcification, involvement of surrounding organs and blood vessels, retroperitoneal lymph nodes, and distant metastasis. Among the 14 cases who completed both CT and MRI plain and enhanced examinations, 6 and 12 cases with hemorrhage of tumor, 12 and 6 cases with tumor vasculature, and 9 and 12 cases with capsule irregularities, were found respectively. Conclusions: The manifestations of CT and MRI have certain characteristics in ACC patients. Most ACCs tend to be large (diameter more than 4 cm), lobulated, and tumor vasculature, with areas of hemorrhage and necrosis, capsule irregularities, and heterogeneous enhancement. CT has advantages in evaluating tumor vasculature over MRI, while MRI has advantages in displaying intralesional hemorrhage over CT.