Meningitis as a presentation of macroprolactinoma.

BACKGROUND: Cerebrospinal fluid (CSF) rhinorrhea and consecutive meningitis are well recognised clinical features of macroprolactinomas invading the skull base and are mainly observed under a dopamine-agonist therapy regimen. To our knowledge, a clinical case of primary meningitis due to an untreated macroprolactinoma, without any history of rhinorrhea, has not been reported previously in the English literature. CASE REPORT: A 64-year-old patient presented with acute meningitis. He had no prior episode of CSF rhinorrhea. Neuroradiological imaging revealed a pituitary tumour with invasion and destruction of the skull base. Massive hyperprolactinaemia was proof of a prolactinoma. The patient underwent transsphenoidal adenomectomy. The skull base defect was sealed with a fascia lata graft. In the postoperative course, no further episode of meningitis and no CSF rhinorrhea occurred. The invasive residual tumour was successfully treated with cabergoline.
CONCLUSION: Macroprolactinomas can present with meningitis without any prior history of CSF rhinorrhea. Surgical repair of the skull base defect is the treatment of choice in order to prevent further episodes of meningitis. Pituitary tumours should be considered as a cause of otherwise unexplained meningitis.