Abstract
Sixty-three pituitary functioning adenomas were analyzed with respect to correlation between the preoperative morphological/endocrinological potentials of the tumor and the postoperative surgical endocrinological'cure rates. There were 38 prolactin, 18 growth hormone and seven ACTH secreting adenomas.
In 38 prolactin secreting adenomas, 16 were microadenomas. A trial of selective total adenomectomy completely preserving the normal pituitary gland was performed in eight cases. The endocrinological cure rate (50%) and the abscence of galactorrhea (50%) were not satisfactory. Attempted complete adenomectomy with a partial hypophysectomy resecting some normal surrounding tissue improved the cure rates to 87%. Large tumors with sella destruction or tumors with a very high preoperative serum prolactin (not always correlated) had poor endocrinological cure rates. The endocrinological cure rate was 30% in the prolactin secreting adenomas with grade III and IV sella turcica (Hardy & Vezina classification). This rate was 40% in the prolactinomas with high preoperative endocrinological potentials (over 500 ng/ml), while it was 80% in the tumors with preoperative serum prolactin of less than 100 ng/ml.
Similar results were obtained in the analysis of growth hormone secreting adenomas. The necessity of postoperative hormonal replacement increased in the larger tumors, 30% in Grades I and II and 50% in Grades III and IV. The hormoral cure rate was 80% in tumors with a preoperative growth hormone level of less than 100 ng/ml and 38% in those with over 100 ng/ml.
The majority of ACTH secreting tumors were microadenomas and had excellent cure rates, 86% in seven cases.
This study strongly suggests that the preoperative morphological/endocrinological potentials are the major factors affecting the postoperative surgical endocrinological cure rates in functioning adenomas. The authors emphasize that the transsphenoidal resection of the pituitary adenomas should be performed while the tumors have low morphological/endocrinological potentials to obtain excellent surgical results.
