Neonatal adrenal hemorrhage detected antenatally

This report describes two cases of neonatal adrenal mass detected antenatally by routine ultrasound (US) examination of pregnant women. Case 1 was recognized by the fetal US at 31 weeks gestation. The mass, located near the right upper pole of the kidney, was echolucent on US examination. A serial US of the mass showed changes of the internal echoes from a cystic lesion to a mixed lesion, and finally to a hyperechogenic lesion due to a neonatal adrenal hemorrhage (NAH). At 33 days, laparotomy was performed, and the pathological finding revealed an NAH owing to the mass bleeding into the adrenal cyst. Case 2 was also detected by fetal US just before birth. The mass of the right upper pole of the kidney was hyperechogenic on US examination. The baby clinically deteriorated after birth because of hypovolemia owing to NAH. A serial US of the mass showed the change from a hyperechogenic to a cystic lesion. Four months later, the mass spontaneously resolved. From the US spectrum, the mass was diagnosed as NAH. These are the second known cases of NAH detected before birth in Japan.