EXPRESSION OF PROHORMONE CONVERTASE, PC2, IN ADRENOCORTICOTROPIN-PRODUCING THYMIC CARCINOID WITH ELEVATED PLASMA CORTICOTROPIN-RELEASING HORMONE

Citation
N. Kimura et al., EXPRESSION OF PROHORMONE CONVERTASE, PC2, IN ADRENOCORTICOTROPIN-PRODUCING THYMIC CARCINOID WITH ELEVATED PLASMA CORTICOTROPIN-RELEASING HORMONE, The Journal of clinical endocrinology and metabolism, 81(1), 1996, pp. 390-395
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Endocrynology & Metabolism
ISSN journal
0021-972X
Volume
81
Issue
1
Year of publication
1996
Pages
390 - 395
Database
ISI
SICI code
0021-972X(1996)81:1<390:EOPCPI>2.0.ZU;2-K
Abstract
An autopsy case of AGTH-producing thymic carcinoid with Cushing's synd rome is reported. The patient was a 63-yr-old man with multiple bone m etastases from an undetermined primary site. Hyperpigmentation was obs erved at the terminal stage. The plasma levels of ACTH, cortisol, chro mogranin A, and urinary 17-hydroxycorticosteroids were extremely high, and ectopic ACTH-producing neuroendocrine tumor was diagnosed. In add ition, plasma CRH was high. Autopsy revealed that the patient had prim ary thymic carcinoid with extensive metastases. Remarkable hyperplasia of the adrenal cortexes and Crooke's hyaline degeneration of the pitu itary gland were consistent with Gushing's syndrome by ectopic ACTH pr oduction. There were multiple CRH-producing cells without degenerative changes in the hypothalamus. The tumor cells were immunoreactive to A CTH, CRH, and the cleavage enzyme PC2. POMC messenger ribonucleic acid and PC2 messenger ribonucleic acid were detected in the tumor cells b y an in situ hybridization method. Expression of PC2 was considered to induce hyperpigmentation by producing alpha MSH. Despite hypercortiso lism and ectopic production of CRH by the tumor cells, hypothalamic CR H cells were not atrophic. This case is a good example to demonstrate the correlation between CRH and the hypothalamo-pituitary-adrenal axis as well as hyperpigmentation in Gushing's syndrome.