A Case of acromegaly associated with subclinical Cushing's disease.
A 54-year-old man with type 2 diabetes was referred to our hospital for endocrine evaluation of acromegaly. Physical examination showed typical acromegalic features without Cushingoid features. Magnetic resonance imaging of the brain revealed the presence of a pituitary macroadenoma. Basal plasma levels of GH and insulin-like growth factor-I under fasting hyperglycemia (202 mg/dl) were markedly elevated. Plasma GH levels paradoxically increased after stimulation with TRH and LH-RH, and decreased after bromocriptine and octreotide administration. Endocrine examination of the hypothalamo-pituitary-adrenal (HPA) axis showed a lack of circadian rhythm of ACTH and cortisol, non-suppressibility to low-dose (1 mg), but suppressibility to high-dose (8 mg) dexamethasone, and normal response to CRH stimulation. The tumor resected by transsphenoidal surgery was histopathologically consistent with the diagnosis of eosinophilic adenoma: positive immunoreactivities of GH, PRL and ACTH were demonstrated, but negative immunoreactivities of prohormone convertase (PC) 1/3 by immunohistochemical method. After surgery, plasma GH and IGF-I levels decreased along with normalization of HPA axis. Metabolic co-morbidities such as diabetes and hypertension disappeared after removal of the pituitary tumor. This is a very rare case of GH-producing pituitary adenoma causing typical acromegaly with concomitant production of ACTH causing subclinical Cushing's disease.
Tsuchiya
Kyoichiro
K
Department of Clinical and Molecular Endocrinology, Tokyo Medical and Dental University Graduate School, Yushima, Tokyo, Japan.
Ohta
Kazuki
K
Yoshimoto
Takanobu
T
Doi
Masaru
M
Izumiyama
Hajime
H
Hirata
Yukio
Y
D000172:Acromegaly / Q000097:blood / Q000150:complications* / Q000601:surgery; D000236:Adenoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D000324:Adrenocorticotropic Hormone / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D047748:Pituitary ACTH Hypersecretion / Q000097:blood / Q000150:complications* / Q000601:surgery; D010901:Pituitary Function Tests; D011859:Radiography
D019382:Human Growth Hormone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone