Sonographic appearances of adrenal schwannomas.

Abstract

To evaluate the sonographic ultrasound (US) appearances of adrenal gland schwannomas. This was a retrospective analysis of 15 cases of schwannomas involving the adrenal gland. The following US features were assessed: size, border, echogenicity, homogeneity, intralesional cystic necrosis, presence of septa, intralesional calcification, posterior acoustic enhancement and blood supply. Of the 15 tumors, seven (46.7%) were located on the left side, and the remaining eight (53.3%) on the right side. The most frequent US appearance of adrenal schwannoma was a single, well-defined and isoechoic mass. The internal echotexture was homogeneous in 2 cases, and heterogeneous in 13 cases, with intralesional cystic areas (n = 11), septa (n = 10) or calcifications (n = 6). Posterior acoustic enhancement was seen in 12 of the 15 cases (80%). On color Doppler US, 86.7% (13/15) of the lesions did not show any vascularity. Adrenal schwannomas usually present on US as well-defined isoechoic masses often with posterior acoustic enhancement, cystic necrosis with septa and poor blood supply. These appearances should suggest the diagnosis of adrenal schwannomas. Nevertheless, additional information from laboratory tests and CT or MR imaging may be required to avoid unnecessary surgery.