Tumors of the gasserian ganglion are of considerable interest because of their rare occurrence, and because of the difficulty in diagnosis. In many of the cases reported, there seems to be no sharp differentiation between those primary to the ganglion and those of the adjacent region, involving the ganglion coincidently. Few, if any, cases reported can be said to have originated within the ganglion itself, but rather in its sheath or the neighboring dura. Hellsten 1 believes that the ganglionic tissue possesses a peculiar resistance to tumor invasion, a fact that is further borne out by the lack of tumor involvement of the spinal ganglions, which is so seldom found. Frazier 2 discusses in detail this unusual condition. At the time Frazier wrote, only fourteen tumors had been exposed at operation, the first being in 1895, by Krogius. Of these fourteen, ten were inoperable. Since that time, Henneberg3 has