Macronodular congenital adrenal hyperplasia in an adult with female pseudohermaphroditism.

We report a case of previously undiagnosed congenital adrenal hyperplasia presenting with virilisation in a 59-year-old woman. Biochemical analysis revealed C-21 hydroxylase deficiency. CT demonstrated adrenal hyperplasia and a 3.8-cm adrenal nodule, raising the possibility of the development of an autonomous adrenal adenoma or carcinoma. The adrenal nodule regressed significantly with oral replacement steroid therapy over the next 30 months, indicating it to be an ACTH-dependent hyperplastic nodule and thus avoiding the need for biopsy or surgical excision. Macronodular adrenal hyperplasia should be considered in the differential diagnosis of a patient presenting with virilisation and an adrenal mass.