Osteoporosis is 1st sign of Cushing’s disease for teen, case warns
Rare disease found to be cause of weak, brittle bones for boy, 15
For a short and thin teenager in Poland, his case of Cushing’s disease was first seen as osteoporosis, a condition that causes bones to become weak and prone to fracture.
The boy, 15 at the time of diagnosis, did not show other typical symptoms of Cushing’s, including weight gain or obesity — generally considered one of the hallmark symptoms of the rare disorder.
His case led authors to argue that whenever a child presents with bone disease, its potential cause should be sought without disregarding a rare one like Cushing’s.
“The highest incidence of [Cushing’s disease] occurs in children aged 12.3-14.1 years,” the researchers wrote, noting that “growth retardation ([affecting] 63-100%)” of these patients is, along with weight gain and facial changes, among the most common symptoms.
The boy’s case was described in the study, “Osteoporosis as the First Sign of Cushing’s Disease in a Thin 16-Year-Old Boy — A Case Report,” published in the Journal of Clinical Medicine.
Osteoporosis in teen with Cushing’s disease started with back pain
In Cushing’s disease, an excess of cortisol in the body is caused by a pituitary adenoma, a usually non-cancerous tumor that forms in the brain’s pituitary gland. Such tumors lead to a range of symptoms, typically including weight gain, skin changes, and extreme fatigue.
Cushing’s in children often leads to stunted growth — specifically short stature for the child’s age — in addition to most of the symptoms also experienced by adults, such as weight gain. However, the disease rarely occurs in youth; “if it occurs, it is more likely to present in older children,” the researchers wrote.
This report described the case of an adolescent boy who was treated for pain and fractures in his spine as a result of osteoporosis. For some people with Cushing’s, weak bones or fractures may be among the first symptoms of the disease.
The boy, nearly 16, was referred to an osteoporosis clinic due to severe back pain, which had started about six months earlier. The pain began while he was receiving treatment with the steroid deflazacort for liver inflammation, known as autoimmune hepatitis, after contracting COVID-19.
His pain was worse with movement and persisted even after treatment with deflazacort was stopped. Dual-energy X-ray absorptiometry (DXA), a type of scan used to measure bone density, revealed the boy had low bone mass.
He also was thin, and short for his age. When doctors examined his growth chart, “it became evident that the boy experienced growth retardation from the age of 11,” the researchers wrote.
An MRI of the spine revealed multiple fractures. Based on these findings and the low bone mass, a diagnosis of osteoporosis was made. The boy was started on calcium supplements and a form of vitamin D called cholecalciferol to reduce the risk of fractures.
Further testing revealed high cortisol levels during night hours, when they are normally low. After an overnight low-dose dexamethasone suppression test, his cortisol levels remained higher than normal.
Dexamethasone is a man-made steroid that turns off the production of cortisol in healthy people. However, in people with Cushing’s, cortisol levels usually do not drop in response to a low dose of dexamethasone.
Case said to be first with such subtle Cushing’s symptoms
The teen’s cortisol levels dropped after a high-dose dexamethasone suppression test, suggesting the excess cortisol levels might be the result of a pituitary tumor.
To confirm their suspicions, doctors ordered a corticotropin-releasing hormone (CRH) test. CRH instructs the pituitary gland to release adrenocorticotropic hormone (ACTH), which in turn prompts the adrenal glands atop the kidneys to produce cortisol.
The test led to “a four-fold increase in ACTH levels and a two-fold increase in serum [blood] cortisol levels,” the researchers wrote, indicating that Cushing’s disease might be the cause behind the boy’s osteoporosis and stunted growth.
The diagnosis of Cushing’s disease was then confirmed by an invasive test called petrosal sinus sampling, which involves measuring ACTH levels in the veins that drain blood and other fluids from the pituitary gland.
Diagnosis should be pursued until all potential causes of the described symptoms, including the rarest ones, are definitively ruled out — even if the clinical presentation, as in the case of our patient, initially does not point towards the final diagnosis.
An MRI of the pituitary gland showed a poorly demarcated or not clearly defined mass, which was treated by transsphenoidal adenomectomy — a surgery used to remove pituitary tumors.
Despite remission, or symptom disappearance, “the advanced bone age of the child (indicating the completion of the growth process) left limited potential for significant improvement in final growth,” the researchers wrote.
“Due to the diagnosed osteoporosis, chronic supplementation with calcium and cholecalciferol was recommended, along with annual follow-up DXA scans,” the team wrote.
This may be the first reported case of a child with Cushing’s “exhibiting such subtle symptomatology,” according to the researchers, who noted that no such cases had been described in the literature to date.
The team urged that this case, while rare, should serve as a reminder to clinicians to not disregard less common disorders when making a diagnosis.
“Diagnosis should be pursued until all potential causes of the described symptoms, including the rarest ones, are definitively ruled out — even if the clinical presentation, as in the case of our patient, initially does not point towards the final diagnosis,” they concluded.