Endoscopic Extracapsular Resection of Pituitary Adenoma in Cushing’s Disease: A Myth or a Reality?

Introduction: Cushing’s disease is one of the rare neurosurgical conditions, it affects one to two persons per million and it is more common in women. Moreover, diagnosis is usually delayed for up to 6 years, with four times greater mortality risk than general population. It is considered one of the diseases difficult to treat because of the high incidence of postoperative recurrence even after remission. Since 2006, Oldfield et al and other groups have demonstrated a higher rate of remission in patients with Cushing’s disease operated upon by extracapsular resection; however, all of these series were operated microscopically.

Methods: This is a prospective descriptive cohort study, conducted in Ain Shams University Hospitals, between 2012 and 2018. Thirty-six patients presenting with hormonal dysfunction due to pituitary over secretion of ACTH were enrolled in this study. Twenty-seven were newly discovered, whereas the remaining 9 were recurrent and 2 of them received postoperative radiosurgery. All patients were operated upon by endoscopic transsphenoidal extracapsular resection utilizing the adenoma pseudocapsule as a surgical resection plane. Excision biopsies were sent for histopathology. No replacement was given early postoperatively and a nadir serum cortisol level below 1 µg/dL within the initial 48 hours after surgery was considered remission.

Results: Remission was achieved in 91% of patients. The remaining 9% (3 patients) experienced only a reasonable reduction in their cortisol level, one had a cavernous sinus invasion and the other 2 had persistent symptoms with no identifiable tumor on imaging. Early relapse was seen in one patient after initial remission due to a new tumor focus on the contralateral side, seen on follow-up MRI. Intraoperative CSF leak was encountered in 33% of cases, however with appropriate repair none of our patients experienced postoperative leakage. No serious complications were encountered in any of our patients, and only 19% (seven patients) experienced diabetes insipidus that was permanent in only one patient. Length of hospital stay ranged from 2 to 4 days.

Conclusion: Endoscopic transsphenoidal resection utilizing the adenoma pseudocapsule is a safe and effective method for treatment of ACTH secreting pituitary adenomas. Our results indicate that a higher remission rate can be achieved than conventional intracapsular resection.

Fig. 1 (A, B) MRI coronal and sagittal T1WI+C showing a left-side microadenoma. (C) Identification of the pseudocapsule and dissection of the tumor from the normal gland. (D, E) Dissection from the diaphragma and the left cavernous sinus wall. (F) Inspection of the tumor bed. (G = gland, T = tumor, TB = tumor bed).

No conflict of interest has been declared by the author(s).