Recovery of hypopituitarism after neurosurgical treatment of pituitary adenomas

Surgery is the treatment of choice for many pituitary tumors; pituitary fun ction may suffer after operation, but relief of pressure on the normal pitu itary may also favor postoperative recovery of hypopituitarism. The aim of this study was to investigate the frequency of new appearance and recovery of hypopituitarism after neurosurgery and try to identify features associat ed with it. Pre- and postoperative anterior pituitary functions were invest igated in 234 patients with pituitary adenomas (56 nonfunctioning, 71 PRL-s ecreting, 66 GH-secreting, 39 ACTH-secreting, 1 LH/FSH-secreting, and 1 TSH -secreting tumor). Eighty-eight new postoperative pituitary hypofunctions a ppeared in 52 patients (12 NF, 14 PRL-secreting, 15 GH-secreting, 10 ACTH-s ecreting, and 1 LW/FSH-secreting adenomas). They corresponded to 27% ACTH d eficiencies tin 29 of the 107 patients with normal preoperative ACTH in who m postoperative evaluation was complete!, 14.5% (15 of 103) new GH deficien cies, 10.5% (15 of 143; P < 0.0005, significantly less than ACTH deficiency ) new TSH deficiencies, 16.5% (20 of 121) new gonadotropin deficiencies, an d 13% (9 of 71) new PRL deficiencies. Preoperatively, 93 were deficient in at least 1 pituitary hormone; after surgery, 45 (48%) recovered between 1 a nd 3 hormones. The 2 patients with LH/FSH- and TSH-secreting macroadenomas did not recover pituitary function. Factors associated with a higher probab ility of postoperative pituitary function recovery were: no tumor rests on postoperative pituitary imaging (P = 0.001) and no neurosurgical (P = 0.001 ) or pathological evidence (P = 0.049) of an invasive nature. Tumor size di d not differ significantly between those who did and those who did not reco ver pituitary function after surgery. Even if clear hypofunction is observed at initial work-up, patients should be reassessed after surgery without substitution therapy, because practical ly half the preoperative pituitary hormone deficiencies recover postoperati vely, eliminating the need for life-long substitution therapy.