Macroprolactinomas are the most frequent subtype of pituitary adenomas. Their treatment has been improved since the onset of dopamin agonists (DA). Nevertheless, DA can cause a cerebospinal fluid (CSF) leakage by shrinking the tumor and lead to a bacterial meningitis. This complication might have lethal consequences.

We conducted an observational, retrospective study in the Pituitary Unit in Pitié Salpêtrière Hospital. A total of 171 patients with macroprolactinomas (larger diameter greater than 10mm) were included in the study. We compared patients who presented cerebrospinal rhinorrhea and/or meningitis, so-called complicated patients (C group), to patients who presented no complications during their follow-up, so-called uncomplicated patients (UC group): no occurrence of rhinorrhea, meningitis.

Cerebrospinal fluid (CSF) leakage has been found in 5% of patients in our large cohort of macroprolactinoma. Determinants of CSF leakage seems to be : adenoma size with concomitant supra- and infrasellar extension, very high prolactin level (>1000µg/l), cabergoline treatment.

Cerebrospinal rhinorrhea is a rare complication of macroprolactinomas, but potentially lethal because of meningitis risk. Anti-pneumococcal and anti-haemophilus vaccination appears to be appropriate in these patients at the time of introduction of DA, to prevent meningitis.