title: A case of ACTH-independent macronodular adrenal hyperplasia associated with multiple endocrine neoplasia type 1.
abstract: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant neoplasia syndrome characterized by the occurrence of tumors in the parathyroid glands, pancreas, and anterior pituitary. Approximately 30-40% of MEN1 patients also have adrenal lesions, such as hyperplasia, benign adenoma, and adrenocortical carcinoma. Most of the cases are hormonally silent. We describe the case of a 60-year-old man with bilateral macronodular adrenal lesions, in addition to parathyroid tumors, multiple insulinomas, and non-functioning pituitary microadenoma. Endocrinological tests revealed subclinical hypercortisolism; midnight cortisol level rose slightly (8.0 µg/dL), although basal plasma ACTH and cortisol levels were within the normal range (19.5 pg/mL and 12.0 µg/dL, respectively). One and 8 mg dexamethasone suppression tests showed cortisol levels of 2.3 and 9.8 µg/dL, respectively. (131)I-adosterol scintigraphy under dexamethasone suppression revealed bilateral adrenal uptake with right-sided predominance. The histological features of the removed right adrenal gland were consistent with ACTH-independent macronodular adrenal hyperplasia (AIMAH): immunoreactivity of 17α-hydroxylase was predominantly observed in the small compact cells, while that of 3β-hydroxysteroid dehydrogenase was exclusively expressed in the large clear cells. The glucose-dependent insulinotropic polypeptide (GIP) receptor was expressed at high levels in compact cells, suggesting that GIP is responsible for the development of AIMAH. Unilateral small adrenal lesions were detected in the patient's 2 children, who also presented with MEN1 symptoms. Genetic abnormalities in the MEN1, p27, and p18 genes were not found, however, the present case may provide a clue to the understanding of the etiology of MEN1 and AIMAH.
authors.affiliation: Department of Endocrinology and Diabetes, Nagoya Ekisaikai Hospital, Nagoya, Japan. myavp@zm.commufa.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Yoshida
authors.forename: Maiko
authors.initials: M
authors.lastname: Hiroi
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Imai
authors.forename: Toyone
authors.initials: T
authors.lastname: Kikumori
authors.forename: Tatsuhito
authors.initials: T
authors.lastname: Himeno
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sasano
authors.forename: Masanobu
authors.initials: M
authors.lastname: Yamada
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Murakami
authors.forename: Sigeo
authors.initials: S
authors.lastname: Nakamura
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Oiso
mesh_terms: D000236:Adenoma / Q000150:complications; D000312:Adrenal Hyperplasia, Congenital / Q000150:complications* / Q000473:pathology; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D003907:Dexamethasone; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000150:complications* / Q000473:pathology; D010282:Parathyroid Neoplasms / Q000150:complications; D010375:Pedigree; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism
chemical_list: D011964:Receptors, Gastrointestinal Hormone; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; C041086:gastric inhibitory polypeptide receptor