Hormone-producing Intestinal Tumor Causes Rare Cushing’s Case
In a rare case, a hormone-producing intestinal tumor led to the development of ectopic Cushing’s syndrome in a 50-year-old man, according to a recent report.
The patient’s high cortisol levels — a hallmark of hypercortisolism — normalized after he underwent surgery to remove both adrenal glands, which are responsible for producing the steroid hormone.
Identifying these types of tumors “is important to improve the patient’s prognosis and quality of life,” the researchers wrote.
The report, “Paraneoplastic Cushing Syndrome in Gastrointestinal Neuroendocrine Tumour,” was published in the journal Case Reports in Oncology.
Cushing’s syndrome is characterized by excessive levels of the hormone cortisol. In many cases, this is caused by a tumor in the brain’s pituitary gland that releases high amounts of adrenocorticotropic hormone (ACTH), a hormone that controls cortisol production.
In about 10% of cases — considered rare cases — ACTH is produced and released by an ectopic extra-pituitary neuroendocrine tumor — a hormone-producing tumor found outside the pituitary gland.
In this report, researchers in France described the case of a man who developed Cushing’s syndrome due to a neuroendocrine intestinal tumor.
The patient was treated in the emergency department in Avignon due to an intestinal obstruction caused by a tumor. Tumor tissue analysis revealed it was a neuroendrocine tumor that had already spread to the liver and lymph nodes.
Following further analysis of the tumor’s tissue, physicians classified it as a G1 neuroendrocine tumor, meaning that fewer than two in every 100 cells — or less than 2% of the cells — making up the tumor mass were dividing.
After discussions with the treating team’s physicians, the patient began treatment with a somatostatin analog — a type of medication used to manage the hormonal imbalance that characterizes Cushing’s syndrome.
One year later, CT scans showed his tumor remained stable, but a physical examination revealed signs of fat accumulation in the face, overall swelling, muscle weakness, and wasting — all suggestive of Cushing’s syndrome.
The patient also complained of excessive thirst, insomnia, and balance problems. Also, his levels of chromogranin A (CgA) — a protein released from hormone-producing cells — increased from 55 nanograms per milliliter (ng/ml) to 199 ng/ml.
The clinicians reported that the patient had high levels of cortisol (hypercortisolism) in the morning, which did not drop after a high-dose dexamethasone suppression test (ODST). The ODST is a standard test used to confirm the presence and the specific causes of hypercortisolism.
He was diagnosed with ACTH-dependent Cushing’s syndrome. MRI scans revealed the patient had a normal pituitary gland, without any tumor, confirming the ectopic source of ACTH.
The man received ketoconazole and sandostatin, which lowered his cortisol levels within a month to a normal range. The patient developed secondary diabetes two months later, which was managed effectively with a long-acting, man-made version of human insulin.
However, four months later, and despite the cancer’s stabilization, his cortisol levels increased once again to the levels seen before he started treatment with ketoconazole. His diabetes also became harder to control and his CgA levels increased.
He underwent chemoembolization for his liver metastases — a treatment that delivers a cocktail of chemotherapy medications and a blocking agent into the blood vessel that supplies tumors in the liver. But this procedure had no effects on his cortisol levels.
The patient then underwent bilateral adrenalectomy, which is a surgical procedure to remove both adrenal glands. The surgery resolved the hypercortisolism and stabilized his diabetes.
One month after the surgery, the patient began treatment with everolimus, a medication that interferes with cancer cell proliferation. One year later, CT scans showed his cancer and CgA values had stabilized.
Overall, “identification of this rare cause of ectopic ACTH secretion can be challenging, but aggressive management is critical to prevent or decelerate the acute decompensation of cancer patients and prolong overall survival,” the researchers wrote.