Vision Restored – Successful Treatment of a Silent ACTH Pituitary Adenoma Presenting With Apoplexy

A previously healthy 57-year-old man abruptly developed horizontal diplopia and severe frontal headaches. On evaluation in the emergency room, he was found to have sixth cranial nerve palsy. Magnetic resonance imaging (MRI) showed a 3.0 cm x 3.0 cm x 1.5 cm growth with mass effect on the optic nerves and left cavernous sinus invasion, but no extension lateral to the carotid artery.He was prescribed dexamethasone and referred to Emory University Hospital for neurosurgical evaluation. The patient’s hormonal workup was remarkable for central hypogonadism. He had no clinical or biochemical evidence of hypercortisolemia or acromegaly. Neuro-ophthalmological evaluation by Nancy Newman, MD, found a bitemporal hemianopia and sixth nerve palsy. At this point, he was referred to neurosurgeon Nelson Oyesiku, MD, PhD, FACS, who removed the tumor via 3-D endoscopic transsphenoidal surgery. Pathology identified an ACTH-positive pituitary tumor. The patient was discharged on postoperative day three and had an uncomplicated postoperative course.

Headaches remitted immediately following surgery, and diplopia improved progressively over the course of a few weeks. Three months following surgery, he had a normal neuro-ophthalmological evaluation, and MRI showed no residual tumor. His hormonal evaluation remained remarkable only for hypogonadism, which was corrected with testosterone replacement therapy. He has been followed at the Emory Pituitary Center with annual MRI scans for more than three years, during which time there has been no evidence of tumor recurrence.

This case illustrates the importance of timely surgical intervention in patients presenting with acute neurological issues caused by pituitary tumors. The patient’s visual loss related to optic neuropathy from suprasellar tumor expansion completely resolved postoperatively. In addition, the sixth cranial nerve palsy caused by the tumor’s extension into the cavernous sinus also resolved entirely following surgery. Tumors that extend to the cavernous sinus are challenging, but can be completely removed by experienced surgeons. Despite the complexity of the procedure and the size of the invasive tumor, the patient experienced no neurosurgical complications or new endocrine deficits.

Immunohistochemical studies should be performed by experienced neuropathologists on tumor specimens of all patients with pituitary adenomas. In this case, it revealed a silent corticotroph adenoma. This entity is defined as a clinically nonfunctioning pituitary adenoma with positive staining for ACTH, but without clinical or biochemical hypercortisolemia. These tumors are potentially more aggressive than ACTH-negative pituitary adenomas.

Emory Pituitary Center neuroendocrinologist Adriana Ioachimescu, MD, PhD, FACE, conducted an analysis of all silent corticotroph adenomas resected by Dr. Oyesiku over the course of 12 years. These patients were younger compared to those with ACTH-negative nonfunctioning pituitary tumors, and all presented with macroadenomas (larger than 1 cm). Among this same cohort, cavernous sinus invasion and preoperative pituitary hormone deficiencies occurred more frequently in patients with silent corticotroph adenomas than in those with ACTH-negative tumors. Long-term followup with annual imaging and judicious use of adjuvant radiation for recurrent tumors yielded similar outcomes in the two groups. Emory researchers’ findings regarding the largest cohort of silent corticotrop.