[A case of adrenal myelolipoma associated with adrenogenital syndrome]

Myelolipoma is a benign non-functioning tumor, and the number of documented cases is increasing in recent years. We report a case of adrenal myelolipoma associated with adrenogenital syndrome. A 65-year-old woman presented with a complaint of abdominal discomfort. CT showed a mass with abundant fatty density in the left adrenal gland suggesting myelolipoma. She was small and thin. External genitalia had a female appearance, but showed type III abnormality in Prader's classification with clitoral hypertrophy. She had a history of primary amenorrhea. Endocrinological examination revealed marked increase in the 17 alpha-hydroxyprogesterone (or 17-OHP) and pregnanetriol levels. On the basis of clinical features and laboratory values, simple virilizing type congenital adrenal hyperplasia due to 21-hydroxylase deficiency was made. The left adrenal tumor was surgically removed and histologically proved to be myelolipoma. Tumor-uninvolved adrenal area adjacent to myelolipoma showed adrenocortical hyperplasia. To our knowledge, this is the first reported case of adrenal myelolipoma to be associated with congenital adrenal hyperplasia, due to 21-hydroxylase deficiency in Japan. The etiology of myelolipoma remains to be not clarified but our case suggests involvement of endocrine disorder in the development of this tumor.