Related Experiment Videos
Hyperthyroidism caused by an ectopic TSH-secreting pituitary tumor
1Division of Endocrinology, Sinai Hospital of Baltimore, Maryland 21215, USA.
Summary
A rare ectopic pituitary tumor secreting thyroid-stimulating hormone (TSH) was discovered in a patient with persistent hyperthyroidism despite treatment. Surgical removal normalized hormone levels, highlighting this unusual cause of TSH elevation.
Area of Science:
- Endocrinology
- Oncology
- Neurosurgery
Background:
- Graves' disease management can lead to hypothyroidism.
- Persistent elevated thyroid-stimulating hormone (TSH) with normal or high thyroid hormones suggests TSH resistance or a TSH-secreting pituitary tumor.
Observation:
- A 45-year-old woman with a history of Graves' disease developed hypothyroidism after radioiodine therapy.
- Despite thyroxine replacement, she exhibited persistently elevated TSH levels with a high TSH alpha-subunit ratio, initially suggesting a pituitary tumor.
- A normal CT scan of the sella turcica did not reveal a pituitary adenoma.
Findings:
- An ectopic pituitary tumor in the nasopharynx was identified during an unrelated examination.
- Histological and immunohistochemical analysis confirmed the mass as a TSH-secreting pituitary tumor.
- Surgical resection of the nasopharyngeal tumor normalized TSH and alpha-subunit levels.
Implications:
- This case represents the first reported instance of an ectopic TSH-secreting pituitary tumor.
- Ectopic pituitary tumors should be considered in the differential diagnosis of unexplained TSH elevation.
- Advances in imaging and histology are crucial for diagnosing rare endocrine disorders.