Microprolactinomas in males treated by transsphenoidal surgery.

OBJECTIVE: To support the opinion that transsphenoidal surgery can be an effective alternative to medical treatment for microprolactinomas in men.

DESIGN: Clinical study with retrospective data analysis.

PATIENTS AND METHODS: Of 46 men who were operated on for prolactinoma in the Department of Neurosurgery of the University of Vienna General Hospital between 1985 and 2000 a microadenoma was detected 11 times (24%).

RESULTS: Median patient age was 41 years (range 32 to 54 years). Symptoms were of endocrine nature in all patients with erectile dysfunction, infertility and gynaecomastia being the initial complaints and having lasted for a median of 13 months (range 7-68 months). Preoperative median serum prolactin (PRL) was elevated to 120 ng/ml (range 41-1000 ng/ml). Radiography by MRI revealed microadenomas with a median diameter of 8 mm (range 4-10 mm). All patients were operated on via the transsphenoidal approach. Endocrine cure as defined by a serum PRL <25 ng/ml was achieved in 8 of 11 patients (73%) after a median follow-up of 7 years (range 2-13 years). In none of the 3 patients with preoperative serum PRL levels >150 ng/ml was a normoprolactinaemia obtained after surgery: 2 require further dopamine-agonist therapy after surgery, 1 after late follow-up. Surgery and medical treatment could restore potency and libido in all but 1 patient, 2 of 3 patients remain infertile.

CONCLUSION: Prolactinomas in males are potentially curable by surgery if detected at an early stage. They most commonly present with insidious signs and symptoms of endocrine disturbances such as loss of libido, impotence and sterility. We stress the importance of early determination of serum prolactin and high resolution magnetic resonance tomography of the sella in male patients with hyperprolactinaemia as this may prevent the possible progression to larger tumours which are rarely curable by surgery and necessitate life-long medical therapy.