Cerebrospinal Fluid Rhinorrhea Following Medical Treatment for an Invasive Macroprolactinoma.

*Correspondence to: Thiti Snabboon MD, Excellence Center in Diabetes, Hormone and Metabolism, BhumiSirimangalanusorn Bldg., 4C Fl., Division of Endocrinology and Metabolism, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Rama IV Road, Patumwan, Bangkok 10330, Thailand, E-mail: thiti.s@chula.ac.th A 38-year-old woman presented with a onemonth history of intermittent watery nasal discharge. Six months prior, she has been diagnosed with an invasive macroprolactinoma from her galactorrhea concurring with a prolactin (PRL) level of 2,715 ng/ mL. A magnetic resonance image (MRI) demonstrated a sellar lesion extending into the base of the skull (Fig. 1A). The tumor responded to bromocriptine 10 mg/d; her PRL level has dropped to 2.5 ng/mL and her 3-month follow-up MRI study has shown a dramatic decrease in the tumor size (Fig. 1B). Cerebrospinal fluid (CSF) rhinorrhea was diagnosed with a highresolution computerized tomography (HRCT) showing bony destruction of the floor of the sphenoid sinus (Fig. 1C). CSF rhinorrhea is an uncommon but well-recognized complication of head trauma or transsphenoidal surgery. However, CSF rhinorrhea following dopamine agonist (DA) therapy for prolactinoma is quite rare. It is presumed that the DA treatment results in tumor regression and then unplugs the eroded area at the base of the skull. The leakage is typically presented within the first month of treatment. This complication may lead to serious conditions including meningitis or brain abscess; however, the role of prophylactic antibiotics remains controversial. An investigation to differentiate CSF fluid from other types of nasal discharge is β-2 transferrin or β-trace protein test. HRCT should be performed to localize the bony defect. Contrast-enhanced imaging or radionuclide cisternography is considered in selected cases. Discontinuation of DA therapy followed by a surgical intervention to repair the skull base defect and simultaneous tumor removal are proposed as a treatment strategy. 1300