Ectopic Thyrotropin-Secreting Tumor in the Nasopharynx Causing Central Hyperthyroidism

Area of Science:

• Endocrinology
• Neurosurgery
• Oncology

Background:

• Thyroid stimulating hormone (TSH)-secreting pituitary tumors (TSH-omas) are rare and challenging to diagnose.
• Ectopic pituitary adenomas present unique diagnostic complexities due to their location and varied hormone secretion profiles.

Observation:

• A 31-year-old man presented with hyperthyroidism (elevated free thyroid hormones, unsuppressed TSH) and elevated follicle-stimulating hormone (FSH).
• Initial investigations, including MRI, did not reveal a pituitary lesion, and TSH-oma was considered unlikely.
• A nasopharyngeal mass was discovered on follow-up MRI, suggesting ectopic pituitary tissue.

Findings:

• Histological examination of the resected nasopharyngeal mass confirmed a plurihormonal pituitary adenoma secreting TSH, growth hormone, luteinizing hormone, and FSH.
• Endoscopic resection led to the normalization of free T4, TSH, and FSH levels within weeks.
• This case underscores the diagnostic difficulties associated with ectopic TSH-secreting pituitary tumors.

Implications:

• Ectopic pituitary adenomas should be considered in the differential diagnosis of hormone imbalances, even with atypical presentations.
• Multidisciplinary approaches involving endocrinology, radiology, and neurosurgery are crucial for accurate diagnosis and management.
• This case expands the understanding of pituitary adenoma heterogeneity and ectopic presentations.