Adrenal cortical adenoma in the spinal canal of an 8-year-old girl.

An ectopic adrenal cortical adenoma containing high levels of androstenedione but without clinically detectable virilizing effects was found in the spinal intradural space of an 8-year-old girl. The tumor, which was located at the L2 level, manifested itself clinically by a short history of bilateral leg pain. It was well encapsulated; therefore, total surgical removal was accomplished. The light microscopic appearance of the tumor was typical of adenomatous adrenal cortical tissue. Ultrastructurally, it also showed characteristic features of steroid-producing tumors, including very abundant smooth endoplasmic reticulum and giant mitochondria with tubulovesicular and circular cristae. Frozen tissue analyzed by radioimmunoassay was found to contain almost 20 times the normal tissue level of androstenedione. There was no elevation of cortisol or aldosterone levels in the tumor. Postoperative magnetic resonance imaging (MRI) scan of the retroperitoneum showed no abnormalities in the patient's adrenal glands. Serum androstenedione levels were normal. We postulate that the adenoma developed from congenital ectopic rests of intraspinal adrenal tissue. Although ectopic occurrence of adrenal cortical tissue has been recorded in other areas, neither such rests nor tumors developing from them have been previously reported within the spinal canal.