Transsphenoidal surgery for microprolactinomas

Introduction: Prolactin-producing pituitary adenomas are still managed controversially. In general, medical treatment with dopamine agonists is to date in most centres accepted as the treatment of first choice for both micro- and macroprolactinomas and usually leads to tumour shrinkage and normalisation of prolactin levels. However, neurosurgical intervention is reported to be an alternative treatment to achieve biochemical cure in microprolactinomas. The goal of this study was to analyse the early postoperative outcome of transsphenoidal surgery for prolactinomas.

Patients and methods: Between 1.3.2004 and 30.6.2006 13 female patients harbouring microprolactinomas underwent surgery (mean age 28.4 years). In all cases, a transsphenoidal approach was used. Assessment of the pituitary function was performed preoperatively, one week and three months postoperatively. In addition, thin collimation MRI was performed before and 3 months after surgery.

Results: The indications of surgery were: patient's preference 6/13 (46.1%), resistance to dopamine agonists 4/13 (30.7%) and intolerance of dopamine agonists due to side effects 3/13 (23.2%). Remission rates in respect to normalisation of serum prolactin at 3, 6 and 12 months were 84.6%, 92.3% and 92.3% (11/13, 12/13 and 12/13). In the case with persistent hyperprolactinaemia the preoperative prolactin level was unusually high (364 ng/ml) and invasion of the medial wall of the cavernous sinus was documented. There were no permanent postoperative complications, especially no deterioration of pituitary function. The mean duration of hospitalisation was found to be 2.5 days and the mean total cost of treatment was 7742 Euro.

Conclusion: Surgical treatment of microprolactinomas is an alternative to long-term medical treatment for (1) high cure rate, (2) low risk and (3) cost efficacy.