PubMed · 16149518
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
Yoshihiko Yamada, Hisahiko Sekihara. 2005. [Corticosterone].. https://pubmed.ncbi.nlm.nih.gov/16149518/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Thymic carcinoid in multiple endocrine neoplasia type 1 (MEN 1) is previously reported as a non-ACTH producing tumor. The present case is a 39-year-old man with mortal outcome from thymic carcinoid and Cushing's syndrome with high plasma ACTH. The symptom was first observed at age 29 and was relieved after extended thymectomy, with reduction of ACTH level. The tumor was positive for ACTH, Grimelius silver staining and Chromogranin A. The finding of primary hyperparathyroidism, pituitary adenoma, and a novel germline nonsense mutation (W423X) established the diagnosis of MEN 1. Cushing's syndrome due to ACTH producing thymic carcinoid should be also considered as one phenotype of the MEN 1 spectrum.
The ectopic ACTH syndrome (EAS) caused by thymic carcinoid is rare and its diagnosis remains a challenge to the endocrinologist. Here are six cases of EAS with a typical Cushing habitus accompanied by hyperpigmentation and hypokalemia. For all six patients, the high dose (8 mg) dexamethasone suppression test (HDDST) showed lack of suppression, computed tomography (CT) scanning documented anterior mediastinal masses, and the mediastenal tumors removed were confirmed as ACTH secreting thymic carcinoids by positive ACTH and NSE staining. Our data indicate that HDDST chest radiologic imaging and other laboratory examinations will greatly assist in diagnosing the thymic carcinoid-induced EAS at an earlier stage, which will significantly improve the long-term survival of the patient.
In 1990, a 55-yr-old woman was admitted to the Medical Department of our hospital for severe hypercortisolism complicated by secondary diabetes mellitus and serious hypokalemia. Although inferior petrosal sinus sampling did not show any significant difference between central and peripheral ACTH concentration, suggesting an ectopic source of ACTH secretion, diagnostic imaging was negative and Cushing's disease due to hyperplasia of the pituitary intermediate lobe was suspected. Medical treatment with bromocriptine and cyproheptadine led to a rapid and stabile normalization of adrenal function, so that after two months cyproheptadine was stopped and bromocriptine was tapered to a smaller dose. An attempt to discontinue medical treatment, carried out 3 yr later, was followed by a quick increase of ACTH and cortisol levels, which were normalized by the resumption of the bromocriptine. Adrenal function remained normal until 1994 when hypercortisolism relapsed despite the treatment. Chest radiography and computed tomography (CT) scan detected a 6 mm nodule in the middle lobe of the lung which proved to be a neuroendocrine tumor, with immunohistochemical positivity for ACTH. Nests of neuroendocrine cells (tumorlets) were also demonstrated in the surrounding lung tissue. After the lobectomy, the patient recovered completely from Cushing's syndrome and no symptoms and/or signs of recurrence have been observed over the subsequent follow-up period. Although cyclical spontaneous Cushing's syndrome could not be excluded, there was strong evidence that medical treatment with bromocriptine might have played a key role in long-lasting remission. To our knowledge, this is the second case described in literature of Cushing's syndrome caused by neuroendocrine lung tumor responsive to bromocriptine.