Rare thymus tumor causes Cushing’s syndrome in UK case
Study underscores importance of early recognition, coordinated care
A malignant tumor of the thymus, a small organ in the upper chest that plays a critical role in the immune system, was identified as the cause of Cushing’s syndrome in a 43-year-old man, according to a recent U.K. case report.
After surgery to remove the thymus, the condition was successfully managed through complete removal of a recurrent tumor in the chest cavity, followed by targeted radiotherapy to help prevent the tumor from returning.
The case underscores the importance of early recognition and coordinated care “in order to facilitate timely initiation of multimodal management such as surgery and radiotherapy,” the researchers wrote.
“Although the data is limited by the rarity of the disease, existing studies suggest that a multidisciplinary, patient-specific approach, including surgery and radiotherapy, offers the best chance of long-term survival,” they added.
The study, “Complete surgical resection of cortisol secreting neuroendocrine thymic tumour: a case report,” was published in the Journal of Cardiothoracic Surgery.
Initial symptoms lead to discovery of tumor
Cushing’s syndrome occurs when the body is exposed to high levels of the hormone cortisol for a long time. In most cases, this happens due to a tumor in the pituitary gland that produces excessive amounts of adrenocorticotropic hormone (ACTH), which triggers excessive cortisol production. This specific form of the condition is known as Cushing’s disease.
Less frequently, the syndrome is caused by ACTH-producing tumors in other parts of the body, where it’s called ectopic Cushing’s. When this abnormal hormone production comes from a malignant tumor, it is referred to as paraneoplastic Cushing’s syndrome.
One uncommon source of this condition are thymus tumors. These tumors are extremely rare — affecting about one in five million people — and in around half of cases, they can cause Cushing’s syndrome through ectopic ACTH production, according to the researchers.
The thymus is a small organ located just behind the breastbone and in front of the heart. It’s part of the immune system and plays an important role during childhood and adolescence by helping develop T-cells, a type of white blood cell that fights infections.
In this report, the researchers described the case of a previously healthy 43-year-old man who went to the hospital after developing Cushing’s syndrome symptoms — including rapid weight gain, high blood pressure, and skin changes.
Tests revealed his condition was caused by a 56-millimeter malignant tumor in his thymus. He underwent robotic thymectomy, a minimally invasive surgery to remove the gland.
Follow-up scans, however, revealed the tumor had come back in the chest cavity, near the heart and major blood vessels. It was close to the nerve that controls breathing and had invaded the lining around the heart (the pericardium).
Because of the tumor’s location and its close proximity to the heart, doctors recommended a second surgery involving both heart and chest surgeons. The man underwent an open-chest procedure in which surgeons completely removed the recurrent tumor and part of the pericardium, along with a small section of the right lung.
Because the tumor was so close to nearby tissue, the man received targeted radiotherapy after surgery to make sure no tumor cells were left behind and reduce the risk of tumor recurrence.
“Although paraneoplastic syndromes such as Cushing’s syndrome are rare manifestations of thymic [hormone-producing] tumours and can result in challenging diagnoses, it is vital to have a high index of suspicion towards ectopic ACTH secretion in order to facilitate timely initiation of multimodal disease management for these patients including surgery and radiotherapy,” the researchers wrote.
They added that surgical management offers “the greatest prognosis in terms of overall survival and disease-free survival”, while adjuvant radiotherapy can help prevent recurrence when the tumor lies close to other tissues.
About the Author
