Rare Case of Adrenal Cushing’s With Unrelated Thyroid Tumor

Screening for endocrine disorders, such as Cushing’s syndrome, is particularly important in patients who have tumors in hormone-producing endocrine glands, such as the thyroid.

This was the take-home message of a recent case report study that described the case of a woman with thyroid cancer who also had Cushing’s driven by the presence of a benign adrenal tumor.

The study, “The occurrence of Adrenocorticotropic hormone-independent Cushing’s syndrome in a woman with the history of papillary thyroid carcinoma: a case report,” was published in the Journal of Medical Case Reports.

In people with Cushing’s syndrome, the levels of the hormone cortisol are excessively high. This may result from prolonged exposure to high-dose corticosteroids, or by the presence of a tumor that produces high amounts of adrenocorticotrophic hormone (ACTH), which controls cortisol production.

About 10% of Cushing’s cases are ACTH-independent and are associated with tumors in the adrenal glands, which sit atop the kidneys and are responsible for cortisol production.

The thyroid is a butterfly-shaped gland in the neck; it controls many aspects of the body’s metabolism.

Thyroid papillary cancer accounts for 85% of all thyroid cancers, placing it as one of the most common types of endocrine cancers. Yet, few cases have been reported in the literature describing the coexistence of thyroid papillary cancer and ACTH-independent Cushing’s.

Researchers in Iran described the case of a 33-year-old woman with a history of papillary thyroid cancer who developed Cushing’s due to a benign adrenal tumor. 

The patient underwent a total thyroidectomy (surgical removal of the thyroid gland) and received iodine 131 to treat her thyroid papillary cancer. Over the course of three years, she gradually developed weakness, a round “moon face”, and gained weight around the abdomen (central obesity), all key features of Cushing’s. 

In the six months prior to her hospital admission, the patient experienced mood swings and ceased having regular menstrual cycles. In addition to thyroid replacement therapies, she was receiving medications to control her high blood pressure and mood issues.  

At the time of admission, she had high blood pressure, excessive facial and body hair growth, purple stretch marks on her abdomen, and mild muscle weakness in her legs.

A diagnosis of Cushing’s syndrome was confirmed when her cortisol levels remained high after a low-dose dexamethasone test. This test measures the levels of cortisol in the blood after patients take dexamethasone, a corticosteroid that normally blocks its production.

At the same time, and because her ACTH levels were low, she ended up being diagnosed with ACTH-independent Cushing’s syndrome. 

A computed tomography scan then revealed the patient had a tumor on her right adrenal gland. She underwent adrenalectomy (adrenal gland removal surgery) and was treated with daily injections of 100 mg of hydrocortisone and oral prednisolone at a daily dose of 5 mg.

Tissue examination of the tumor extracted during surgery confirmed it was  benign and made up mainly of fatty tissue, with no signs of bleeding or tissue necrosis (death).

Within four months, most of her symptoms had partially resolved, including weight gain and irregular menstruation.

According to study’s authors, this was one of the rare cases in which thyroid cancer was found in a patient with unrelated Cushing’s syndrome.

“ACTH-independent Cushing’s syndrome due to adrenal tumor and papillary thyroid cancer occur sporadically. The co-occurrence of two endocrine tumors with different origins is rare,” they wrote.

“It is recommended that the occurrence of other endocrine neoplasms [tumors] be considered when an endocrine tumor is diagnosed,” the investigators concluded.