Endoscopic Endonasal Resection of a Thyroid-Stimulating Hormone-Secreting Pituitary Adenoma With Invasion of the Medial Wall of the Cavernous Sinus.

Thyroid-stimulating hormone-secreting adenomas (TSH-oma) are exceptionally rare.1 The primary treatment is surgical resection with radiation and pharmacotherapy postoperatively if subtotal resection, especially with cavernous sinus invasion.2 We present the case of a 29-year-old man with TSH-oma with cavernous sinus medial wall invasion. This is the first documented case with selective resection of the cavernous sinus medial wall to achieve a complete resection and biochemical remission in TSH-oma through endoscopic endonasal approach. The patient had elevated TSH and thyroid hormones with symptoms of weight loss, palpitations, excess sweating, and decreased endurance. MRI revealed a 1.3 × 2.1 × 1.2 cm contrast-enhancing sellar mass with rightward pituitary gland displacement without evidence of cavernous sinus invasion (Knosp 2). The patient consented to procedure/publication. No institutional review board approval needed per institution. We performed standard resection of the firm sellar tumor portion and noted that there was tumor invasion into the left cavernous sinus medial wall dura. The bony opening was expanded to expose the anterior wall of the cavernous sinus, which was opened to identify the cavernous internal carotid artery and the medial wall attachments. The thickened medial wall was completely resected. We achieved a complete tumor resection, and the patient's TSH and thyroid hormone dropped to a desired threshold.3 Tumor stained for GATA3 and PIT1, characterizing the TSH-oma.4,5 Understanding cavernous sinus vascular and ligamentous anatomy allows for safe separation of invaded medial wall dura from the cavernous internal carotid artery,6 allowing for a more complete tumor resection, improving surgical cure rates, and sparing the patient from future radiation and pharmacotherapy.