ACTH-producing Lung Tumors Hard to Detect, But May Be Cured with Surgery

Ectopic Cushing’s syndrome can be challenging to diagnose, especially when it comes identifying the problem source. But appropriate hormone management protocols, used in combination with advanced imaging methods, may help physicians identify ectopic ACTH-producing tumors.

The findings in a case report of a young man with ectopic Cushing’s syndrome were published in the International Journal of Surgery Case Reports, under the title “Case report: Ectopic Cushing’s syndrome in a young male with hidden lung carcinoid tumor.”

Cushing’s syndrome is caused by high amounts of glucocoticosteroids in the blood. The most common cause is a malfunction of the glands that produce these hormones. In some cases, however, the disease may be caused by tumors elsewhere in the body that have the ability to produce adrenocorticotropic hormone (ACTH).

In half of all Cushing’s patients, ectopic ACTH is produced by small lung cell carcinomas or lung carcinoids (a type of slow-growing lung cancer). But some tumors in the thymus and pancreas also have been found to produce ACTH.

Researchers at Damascus University Hospital in Syria presented the case of a 26-year-old man who had ectopic Cushing’s syndrome due to lung carcinoids.

The patient presented with increased appetite and rapid weight gain for more than a year. These were associated with headache, fatigue, proximal muscle weakness, and easy bruising. He had no family history of hormonal disorder.

Based on the initial physical and symptom evaluation, the clinical team suspected Cushing’s syndrome. Blood analysis revealed high levels of cortisol and ACTH hormones, which supported the diagnosis.

Administration of dexamethasone, a treatment used to inhibit the production of glucocoticosteroids by the pituitary gland, reduced cortisol levels within normal range, but not ACTH levels. This led to the diagnosis of ectopic Cushing’s syndrome.

The next step was to identify the tumor causing the syndrome. The team conducted imaging studies of the brain, chest, and abdomen, but found no tumor.

Because ectopic ACTH is commonly produced by lung cancers, the team then analyzed the patient’s lungs. Again, they failed to detect a tumor.

The patient was discharged with prescription of 200 mg of Nizoral (ketoconazole) once-daily, calcium, and vitamin D. After three months of treatment, he remained stable, with no evidence of symptom improvement.

At this point, the team decided to surgically remove both adrenal glands in an attempt to reduce the hormone levels. Treatment with prednisolone 5 mg and fludrocortisone 0.1 mg once daily was initiated, along with calcium and vitamin D.

Eighteen months later, the patient’s condition worsened and he required hospitalization.

Imaging tests targeting the neck, chest, and abdomen were conducted again. This time, physicians detected a 2 cm mass in the middle lobe of the right lung, which was removed surgically. Detailed analysis of the small tumor confirmed that it was the source of the excessive ACTH.

“ACTH secreting tumors can be very hard to detect,” the researchers stated. “Initial failed localization is common in ectopic ACTH syndrome and it is usually due to carcinoid.”

Cases where the ectopic ACTH production is caused by a carcinoid tumor can be challenging to diagnose because tumors are small and relatively slow-growing. Imaging data is often hard to analyze and the tumors can be confused with pulmonary vessels, the researchers explained.

“In such cases we should first aim to lower blood cortisol medically or through bilateral adrenalectomy to avoid Cushing’s complications,” which should then “be followed up through imaging studies (CT, MRI, scintigraphy or PET) to detect the tumor and resect it, which is the definitive treatment of these patients,” the researchers concluded.

From https://cushingsdiseasenews.com/2017/12/12/case-report-ectopic-acth-producing-lung-tumors-can-hard-detect/

Food-dependent Cushing syndrome: a new entity of organic hypercorticism

Matejka G, et al. Rev Med Interne. 1996.

Abstract

Diagnosis of Cushing’s syndrome is quite difficult in endocrinology. Spontaneous Cushing’s syndrome is usually divided into two subgroups, one which is dependent on corticotropin (ACTH) and another one which is not.

In the first class are Cushing’s disease, the ectopic corticotropin syndrome and the rare ectopic corticotropin-releasing hormone (CRH) syndrome; these ACTH-dependent Cushing’s syndrome have usually diffusely enlarged adrenal glands.

In the second class are cortisol producing unilateral adrenocortical adenomas or carcinomas, and the recent Cushing’s syndrome with food dependent periodic hormonogenesis.

This food dependent Cushing’s syndrome is an ACTH-independent Cushing’s syndrome with multinodular enlargement of both adrenal glands. Pathogenesis is an aberrant adrenal sensitivity to physiologic secretion of gastric inhibitory peptide (GIP). Ectopic expression of GIP receptors on adrenal cells involve pathologic food induced cortisol secretion.

Food dependent Cushing’s syndrome is a new cause of Cushing’s syndrome. Food induced cortisol secretion may have to be explored in the ACTH-independent Cushing’s syndrome.

PMID

8758532 [PubMed – indexed for MEDLINE]

Full text

Full text from provider (Elsevier Science) Article in French.

From http://www.ncbi.nlm.nih.gov/m/pubmed/8758532/

Biography of a Food-Dependent Cushing’s patient

Small cell carcinoma of the vagina causing Cushing’s syndrome by ectopic production and secretion of ACTH

Hope found this interesting info for us:

Small cell carcinoma of the vagina causing Cushing’s syndrome by ectopic production and secretion of ACTH: a case report.

K M Colleran, M R Burge, L A Crooks, R I Dorin

Department of Medicine, Albuquerque VA Medical Center and University of New Mexico School of Medicine, 87108, USA.

BACKGROUND: Small cell carcinomas of pulmonary or extrapulmonary origin are neuroendocrine tumors classically associated with ectopic hormone production, particularly ACTH secretion resulting in Cushing’s syndrome. However, ectopic Cushing’s syndrome has not previously been reported in the setting of small cell carcinoma of the vagina.

METHODS: A primary vaginal tumor with hepatic metastases was evaluated with light microscopy. Serum cortisol and plasma ACTH levels were evaluated by radioimmunoassay and immunoradiometric assay, respectively, during a standard high-dose (8 mg) overnight dexamethasone suppression test.

RESULTS: Vaginal small cell carcinoma with hepatic metastases was demonstrated. Electrolyte abnormalities, elevated cortisol and ACTH levels, and failure to suppress ACTH secretion during high-dose dexamethasone administration confirmed the diagnosis of ectopic ACTH syndrome.

CONCLUSIONS: This case report establishes a clinical association between vaginal small cell carcinoma and ectopic Cushing’s syndrome, confirming the neuroendocrine potential of this malignancy and features common to small cell neoplasms originating in other sites.

More information and citations here: http://lib.bioinfo.pl/pmid:9190988

 

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