Spontaneous cerebrospinal fluid rhinorrhea indirectly caused by brain tumor--report of two cases and review of the literature.

Two cases of nontraumatic cerebrospinal fluid rhinorrhea were presumed to be an indirect manifesta tion of brain tumor. One patient had a parietal convexity meningioma and the other a cerebello pontine angle neurinoma. Following excision of the tumors these patients spontaneously developed cerebrospinal fluid rhinorrhea, which disappeared after the repair of fistulas at the base of the frontal fossa. In such cases the rhinorrhea may be caused by fragility of certain structures as a consequence of long-standing increased intracranial pressure due to brain tumor.