Sonographic Detection of Accessory Adrenal Tissue in Neonates.

Objectives-The purpose of this study was to describe the incidence and appearance of accessory adrenal tissue in neonates, as diagnosed by high-resolution sonography, and increase the awareness of this entity. Methods-We examined the adrenal glands in 153 neonates referred for renal and urinary tract sonography at our institution between January 2014 and January 2015. All kidneys and adrenal glands, except for ectopic kidneys, were scanned with the neonate prone and a linear array transducer with frequency of 11 or 14 MHz. Results-In 9 neonates (5.9%), sonography showed a round, well-defined structure adjacent to the adrenal gland with a hyperechoic center and hypoechoic periphery, similar to the echogenicity of the normal adrenal medulla and cortex, respectively. The largest diameter of the structure measured 2.9 to 4.5 mm. On follow-up studies, which were available for 7 neonates, the structure was not evident, and the suprarenal area was normal. Conclusions-Accessory adrenal tissue can be identified in the suprarenal area in neonates with high-resolution sonography. Radiologists and sonographers caring for neonates should be aware of this finding and not confuse it with disease.