INTRASELLAR PITUITARY TISSUE PRESSURE, TUMOR SIZE AND ENDOCRINE STATUS - AN INTERNATIONAL COMPARISON IN 107 PATIENTS

In a two-centre study, intrasellar pituitary tissue pressure was measu red at transsphenoidal surgery in 107 patients with pituitary adenomas or intrasellar cysts. 'Normal' ISP in patients under anaesthesia with small microadenomas (< 5 mm diameter) or a partial empty sella was 12 +/- 3 mmHg. Raised ISP (> 15 mmHg) was found in 75 % of cases. The hi ghest pressures were recorded in tumours with parasellar invasion (30 +/- 2; p < 0.01) irrespective of size and extension in other direction s. In non-invasive lesions there was no correlation between the level of raised ISP and tumour size. Hypopituitarism and stalk compression s yndrome were both associated with higher ISP than patients with normal pituitary function.