[Pituitary adenoma with widespread extrasellar extension (chief topographo-anatomic features)]

A group of hypophyseal adenomas with extensive extrasellar spread (179 patients) is distinguished and the main topographo-anatomical characteristics of the tumors are determined. The most important characteristics are a large size of the adenoma and growth in many directions with involvement of several structures of the skull and brain. Frequent (up to 70%) invasive growth is typical of such hypophyseal adenomas irrespective of the histological structure. Multiple anastomoses form between the vessels of the tumor and the vascular networks of all anatomical structures with which the tumor comes in contact. These tumors are always separated from the brain matter by the pia. mater. The invasive character of the growth of hypophyseal adenomas makes their radical removal less possible. Maximum effect of surgery may be expected in demarcated growth of the hypophyseal adenoma, including cases with its extensive extrasellar spread.