Association of an epidermoid tumor with an aneurysm of the anterior communicating artery.

A case of epidermoid tumor enveloping an aneurysm of the anterior communicating artery is reported. Four embryologically similar epithelial tumors of the central nervous system associated with intracranial aneurysms, all craniopharyngiomas, have previously been reported. Theories attempting to relate tumor and aneurysm are discussed. The incidence of aneurysm associated with tumor is difficult to estimate and may be no greater than the probability of their coincidence by chance alone.