LAUSR

BACKGROUND Nonsteroidal androgen receptor blockers like flutamide have been described as an adjuvant treatment for preoperative shrinkage of extensive juvenile nasopharyngeal angiofibroma. We present a case of cerebrospinal fluid (CSF) leak due to flutamide-induced tumor shrinkage. CASE REPORT A 15-year-old male with a prior diagnosis of juvenile nasopharyngeal angiofibroma stage IIIB on preoperative flutamide for 3.5 weeks presented with altered sensorium, meningeal signs, and clear watery nasal discharge consistent with CSF leak. Computed tomogram of the head revealed air in the ventricle and repeat contrast-enhanced magnetic resonance imaging showed significant tumor shrinkage in the area of the anterior skull base. This patient had an atypical pattern of tumor extension into the anterior skull base through the roof of posterior ethmoid and sphenoid sinus, which are inherently weak areas of the skull base, thereby predisposing the CSF leak on tumor shrinkage. CONCLUSION CSF leak is a rare complication following flutamide therapy, especially if large areas of the anterior skull base are involved.