Cavernous Sinus Involvement in Pituitary Adenomas

Introduction: The incidence of cavernous sinus (CS) involvement by pituitary adenoms is not well documented. The management of the cavernous component of the tumor is controversial. Here we report our experience with CS involvement in pituitary adenomas and review the long term results following endoscopic resection of pituitary adenomas with CS involvement.

Methods: We retrospectively reviewed the Stanford University Pituitary Adenoma database. Between the years 2007 and 2012, we identified 183 patients who underwent endoscopic resection of pituitary adenomas by the senior author (G.R.H). CS involvement was defined by the presence of tumor within the wall of the sinus or lateral to the medial wall of the sinus.

Results: Out of the 183 tumors, 77% (141/183) were Macroadenomas (>1cm) and 23% (42/183) were Microadenomas (1 cm or less). The median age was 50 years (range: 18–89years). All had pathological confirmation of the diagnosis. The male to female ratio was 1:1.2. Nonfunctional pituitary adenomas represented 60% (110/183) of the tumors. Median follow-up was 36 months (range: 1week - 78 months). We identified 42 (23%) cases of pituitary adenoma with CS involvement. Functional adenomas represented 45% (19/42) of the adenomas with CS involvement. ACTH secreting adenomas had the highest involvement at 42% (8/19) of all functional adenomas involving the CS. The risk of CS involvement was 40% (8/20) for ACTH secreting adenomas, 24% (6/25) for GH secreting adenomas, 19% (5/26) for prolactin secreting adenomas, and 21% (23/110) for non-functional adenomas. Grading the tumors according to the WHO grading for adenoma was not associated with significant difference in the CS involvement. 33% (14/42) of tumors with CS involvement required further treatment, 11 radiation treatments and 3 surgical resections, for residual or progressive disease. Only 3% (4/141) of tumors with no CS involvement required further treatments, 1 radiation treatment and 3 surgical resections, for residual or progressive disease. Neurological and systemic complication rates did not increase in cases with CS involvement.

Conclusion: Involvement of the CS with tumor occurs in one quarter of pituitary adenoma cases. Functional adenomas have higher risk for CS invasion compared with non-functional adenomas, with ACTH secreting adenoma the highest among all groups. The involvement of CS led to further intervention in our patients, which may be explained by the high number of functional adenomas involving the sinus in our group. Endoscopic resection of tumors involving the CS could be safely performed without an increased risk of postoperative neurological complications.