Spontaneous Cerebrospinal Fluid Leak after Initiation of Dopamine Agonist Therapy in Macroprolactinomas: Two Case Reports and a Literature Review

ABSTRACT Objective To describe 2 spontaneous cerebrospinal fluid (CSF) leaks complicating treatment of macroprolactinoma (MPRL) with dopamine agonist (DA) therapy. Methods We present the 2 cases of spontaneous, DA-related CSF leaks. Prolactin levels were used to assess hyperprolactinemia. Beta-2 transferrin was tested in rhinorrhea fluid, and magnetic resonance imaging was used to assess the sella. Results Case 1 was a 45-year-old woman with a history of MPRL, recently started on bromocriptine at 15 mg/day, presented with clear rhinorrhea, headache, and nuchal rigidity. Magnetic resonance imaging showed a large sellar lesion extending into the cavernous sinuses, posterior sphenoid sinuses, and suprasellar cistern. Computed tomography revealed areas concerning for bony erosion, likely representing leak sites, and the rhinorrhea fluid was positive for beta-2 transferrin, confirming the CSF source. Empiric antibiotics for meningitis were given and she underwent urgent neuroendoscopic, transsphenoidal CSF leak repair and debulking of the pituitary mass. Case 2 was a 55-year-old man with a 10-year history of untreated MPRL who was started on bromocriptine at 5 mg/day 2 weeks prior to admission. He presented with clear rhinorrhea and a metallic taste in his mouth, worse with the Valsalva maneuver. Imaging confirmed clinical suspicion and he was taken for surgery. A high-flow CSF leak was encountered once the tumor was debulked. This was repaired with an abdominal fat pad graft. Both patients developed diabetes insipidus and required postoperative adjuvant DA therapy. Conclusion Spontaneous CSF leaks can complicate medical therapy of large MPRL with underlying skull defects, typically within weeks of initiation of DA. This should prompt clinicians to educate patients about the symptoms of potential CSF rhinorrhea and encourage them to promptly report them.