Relationship Between Benign Intracranial Tumor Location and the Side of Spontaneous Cerebrospinal Fluid Leak.

AIM: To present cases of spontaneous cerebrospinal fluid (CSF) rhinorrhea and otorrhea, and to conduct a systematic literature review examining the relationship between benign tumor location and the leak side. MATERIAL and METHODS: A PRISMA-based systematic review was conducted to evaluate studies on spontaneous CSF leaks caused by benign intracranial tumors, alongside three newly reported cases. RESULTS: All three cases exhibited CSF leaks ipsilateral to the tumor: Case 1 involved a pituitary ACTH-secreting macroadenoma with rhinorrhea; Case 2, a pineocytoma with hydrocephalus and nasal encephalocele; and Case 3, a petromastoid meningioma with otorrhea. In the systematic literature review, 28 of 125 studies met the inclusion criteria. The median patient age was 42 years, with a male-to-female ratio of 16:12. Macroprolactinoma was the most frequent tumor (25%), primarily located in the sella (46.4%). Tumors were located at the midline (39.3%), right side (35.7%), or left side (25%). The sphenoid sinus was the most common site of CSF leak (39.3%). The leak occurred through the right nostril (39.3%), left nostril (39.3%), both nostrils (10.7%), right ear (7.1%), and both the nostril and ear (3.5%). Hydrocephalus was present in 25% of cases. CONCLUSION: Although our cases demonstrated ipsilateral leaks, the literature review revealed equal rates of left-sided rhinorrhea, even with midline or right-sided tumors, suggesting skull base bone destruction alone does not explain CSF leaks, particularly in benign intracranial tumors outside mastoid involvement. Careful patient history regarding the side of rhinorrhea, comprehensive preoperative imaging, and hydrocephalus evaluation are essential for identifying the leak site and preventing complications, such as recurrent meningitis.