Hindawi Publishing Corporation Case Reports in Medicine Volume 2009, Article ID 916891, 4 pages doi:10.1155/2009/916891 Case Report Two Adults with Adrenal Myelolipoma and 21-Hydroxylase Deﬁciency Ingrid Nermoen,1, 2 Ivar Følling,1, 2 Kjetil Vegge,3 Arne Larmo,3 Bjørn Gunnar Nedrebø,4 Eystein Sverre Husebye,4, 5 and Kristian Løva˚s4, 5 1 Department of Endocrinology, Akershus University Hospital, 1478 Lørenskog, Norway 2 Institute of Medicine, Faculty Division Akershus University Hospital, University of Oslo, 1478 Lørenskog, Norway 3 Department of Radiology, Akershus University Hospital, 1478 Lørenskog, Norway 4 Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway 5 Institute of Medicine, University of Bergen, 5021 Bergen, Norway Correspondence should be addressed to Ingrid Nermoen, ingrid.nermoen@ahus.no Received 21 April 2009; Accepted 20 July 2009 Recommended by Paul Kaplowitz We present incidentally discovered adrenal myelolipomas in two adult males with untreated congenital adrenal hyperplasia (CAH). The patients had simple virilizing form of CAH due to mutations in the CYP21 gene coding for 21-hydroxylase; one was heterozygous for the I172N mutation and the other compound heterozygous for the I172N and I2splice mutations. The masses were not removed since myelolipomas are considered benign tumors, and the tumor size did not increase during four- and nine- year observation periods. An adrenal myelolipoma is an important exception to the rule that large tumours should be removed. Untreated CAH with prolonged excessive ACTH stimulation might contribute to the growth of adrenal masses. CAH should be considered as a diﬀerential diagnosis of patients with adrenal masses or adrenal myelolipomas. Copyright © 2009 Ingrid Nermoen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. Introduction Adrenal incidentalomas are common; the challenge is to rule out malignancy or excess hormone secretion [1]. Myelolipo- mas are benign endocrine inactive tumors composed of adrenal, adipose, and myeloid tissue, representing 1.5%–9% of adrenal incidentalomas; the radiological characteristic is round, sharp-demarcated lesion with negative attenuation values because of its high fat content [2–5]. Large adrenal masses should usually be removed, but myelolipomas usually do not need resection. However, many of the reported cases were diagnosed after adrenalectomy. Rarely, myelolipomas have been associated with hormone excess syndromes, such as congenital adrenal hyperplasia (CAH) [6–10]. We here report two cases, which illustrate that large adrenal myelolipomas need not to be surgically removed and that CAH must be considered in patients with adrenal inciden- talomas. 2. Case Report 1 In 1999 a 50-year-old man presented with a right adrenal mass 5.7 × 5.1 × 1.9 cm. Medical history revealed precocius puberty at age 4, and he was diagnosed with “Morbus Glan- dulae Suprarenalis” when he was 9. Urinary 17-ketosteroids were found elevated, but suppressible with dexamethasone. He was treated with cortisone acetate 12.5 mg thrice daily from age 9, but at 18 he stopped the medication, after which he felt that his general wellbeing is improving. After this time he was lost to follow-up. At the age of 37 he underwent radioiodine treatment for thyrotoxicosis. He was otherwise healthy, working full time, and was the father of one child. In spite of radioiodine treatment he felt he had persistent goitre, and his general practitioner referred him to a cervical CT, which due to his short stature included the upper abdomen. Pronounced bilateral adrenal hyperplasia and a 5.7 cm in diameter tumor described as a typical adrenal