Microsurgical anatomy of the diaphragma sellae and its role in directing the pattern of growth of pituitary adenomas.

Abstract

To evaluate the anatomic aspects of the diaphragma sellae and its potential role in directing the growth of a pituitary adenoma. Twenty cadaveric heads were dissected and measurements were taken at the level of the diaphragma sellae. The diaphragma sellae is composed of two layers of dura mater. There is a remarkable variation in the morphology of the diaphragm opening. The average anteroposterior distance of the opening was 7.26 mm (range, 3.4-10.7 mm) and the average lateral-to-lateral distance was 7.33 mm (range, 2.8-14.1 mm). The variability in the diameter of the opening of the diaphragma sellae could explain the growth of pituitary tumors toward the cavernous sinus or toward the suprasellar region.