Cabergoline-Induced Pneumocephalus Following Treatment for Giant Invasive Macroprolactinoma Presenting With Spontaneous Cerebrospinal Fluid Rhinorrhea

Cerebrospinal fluid (CSF) rhinorrhea is rarely reported as the first presenting feature of giant invasive macroprolactinomas. Cerebrospinal fluid rhinorrhea is usually reported as a complication of trauma, neurosurgical, and skull-based procedures (such as pituitary surgery or radiations), and less frequently after medical treatment with dopamine agonists (DAs) for macroprolactinomas. This phenomenon results from fistula creation that communicates between the subarachnoid space and the nasal cavity. Meanwhile, pneumocephalus is another well-recognized complication after transsphenoidal surgery for pituitary macroadenomas. This entity may present with nausea, vomiting, headache, dizziness, and more seriously with seizures and/ or a decreased level of consciousness if tension pneumocephalus develops. Case reports about the occurrence of spontaneous pneumocephalus after medical treatment with DAs without prior surgical interventions are scarce in the literature. Our index case is a young man who was recently diagnosed with a giant invasive prolactin-secreting pituitary macroadenoma with skull base destruction. A few months before this diagnosis, he presented with spontaneous CSF rhinorrhea with no history of previous medical or surgical treatment. In this case report, we report an uncommon presentation for giant invasive macroprolactinoma with a CSF leak treated with cabergoline that was subsequently complicated by meningitis and pneumocephalus. This is a very rare complication of cabergoline therapy, which occurred approximately 1 month after treatment initiation.