Papillary meningioma arising from the confluens sinuum with multidirectional extension through venous sinuses.

Successful removal of a meningioma arising from the confluens sinuum is described. This tumor extended multidirectionally through the venous sinuses (superior sagittal sinus, bilateral transverse sinuses, straight sinus, and occipital sinus) and protruded like a club in nodular pattern from the left inner surface of the confluens sinuum into the left occipital lobe. The tumor was completely removed via a bilateral large parieto-occipito-suboccipital craniotomy. Angiographically, unusual venous drainage from the vein of Galen into the superior sagittal sinus was demonstrated. Histologically, this tumor was a papillary meningioma characterized by two types of papillary structure in many areas.