Endoscopic Extracapsular Resection of an Adrenocorticotropic Hormone–Secreting Macroadenoma with Selective Resection of the Medial Cavernous Sinus Wall

Abstract

Biochemical remission of adrenocorticotropic hormone (ACTH)-secreting macroadenomas can be challenging to achieve.1,2 Staying outside the adenoma pseudocapsule is an important technique to achieve gross total resection.1-3 Dural invasion is an important recognized factor that can prevent biochemical remission. In particular, invasion of the medial wall of the cavernous sinus has been implicated as an important determinant in remission and/or recurrence of ACTH-secreting macroadenoma.4,5 A 27-year-old patient presented with severe clinical features and biochemical workup consistent with ACTH-dependent hypercortisolism. Urinary free cortisol was nearly 10 times the upper limit of normal, and prolactin and insulin-like growth factor 1 were moderately elevated at 405 ng/mL and 577 ng/mL, respectively. Magnetic resonance imaging of the brain revealed a 2.4-cm pituitary macroadenoma contacting the left medial wall of the cavernous sinus (CS) and a compressed pituitary gland covering the right medial wall CS. The video demonstrates the technique for resection of the macroadenoma using a pseudocapsular technique with intermittent controlled central debulking to soften the tumor. The tumor had significant adherence to the left medial CS wall, and therefore the left CS was opened from a lateral-to-medial approach. Care must be taken to identify parasellar ligaments and watch for the inferior hypophyseal artery.1-3 The medial wall CS specimen revealed focal invasion of adenoma cells. The tumor stained for ACTH, prolactin, and growth hormone, and Ki-67 index was 1%. The patient went into biochemical remission postoperatively and had significant improvement in preoperative symptoms.