CSF Rhinorrhea: An Early Complication of Dopamine-Sensitive Macroprolactinoma

Abstract

Objective: Cerebral spinal fluid (CSF) leak is a known surgical complication of invasive macroprolactinomas. Case reports suggest this complication can occur with dopamine agonist treatment alone.Methods: We present clinical features, imaging, and biochemical characteristics of one such case of an invasive macroprolactinoma complicated with early CSF leak.Results: A 35-year-old obese male presented with weight gain of over 100 pounds within the last year and absent morning tumescence. Laboratory evaluation was notable for elevated total prolactin (PRL) (4,655 ng/mL) and low total testosterone (24 ng/dL). Magnetic resonance imaging (MRI) revealed a large pituitary adenoma (4.2 × 2.5 × 3.5 cm) extending into the cavernous and sphenoid sinuses, partially eroding the sphenoid bone. Dopamine agonist, cabergoline 250 μg twice/week was started. After two doses, the patient developed CSF rhinorrhea and was hospitalized. Adenoma was smaller in size (4.1 × 1.9 × 3.3 cm), and total PRL declined to 824 ng/mL. An endoscopic subtotal resection of adenoma with CSF leak repair was performed. Treatment with cabergoline was continued, resulting in complete resolution of CSF leak within a few days. Two months later, cabergoline dose was increased to 500 μg twice a week as adenoma size remained unchanged. One month later, MRI showed regression of the pituitary tumor with cystic changes. Serum PRL level substantially declined (total PRL, 102 ng/mL).Conclusion: Clinicians should be highly observant of and educate patients about CSF rhinorrhea as potential early consequence of medical therapy of macroprolactinoma to avoid misdiagnosis and fatal sequelae of this complication.Abbreviations: CSF cerebral spinal fluid; DA dopamine agonist; MRI magnetic resonance imaging; PRL prolactin