A large endoscopic pituitary cohort assessing the predictive value of the modified Knosp classification for surgical resection.

Vergeer, Timmermans, Postma and colleagues analyzed 482 patients treated with endoscopic transsphenoidal surgery. Gross-total resection declined progressively with increasing modified Knosp grade, with a marked difference between low-grade disease and cavernous-sinus invasive tumors.

The modified Knosp grade emerged as the strongest independent predictor of complete resection, supporting the practical value of distinguishing 3A, 3B and grade 4 disease for surgical planning and patient counseling.

Why it matters

For pituitary surgery, this paper gives clinically useful numbers to a classification used every day. It strengthens the role of the modified Knosp system not only as a radiological descriptor, but as a preoperative predictor of resectability and a framework for discussing cavernous-sinus invasion and expected extent of resection.

Reference

Vergeer RA, Timmermans JHJ, Postma MR, et al.
The value of the modified Knosp grade in pituitary adenoma surgery.
World Neurosurgery. Published online September 23, 2026.
DOI: 10.1016/j.wneu.2026.125362
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