Discrepancy between magnetic resonance imaging and cranial nerve neuropathies associated with the involvement of diffuse large B-cell lymphoma（DLBL）.

An 83-year-old female developed diffuse large B-cell lymphoma（DLBL） of the left nasal cavity. Complete remission was achieved after two courses of Rituximab and CHOP（R-CHOP） . During the fourth course of R-CHOP, sensory disturbance and palsy of the left face developed. Left trigeminal nerve swelling was observed in magnetic resonance imaging（MRI） followed by double vision in the left eye, and MRI revealed swelling of both trigeminal nerves but not of the abducens nerve. Although the swelling of the trigeminal nerves and the double vision subside after administration of prednisolone, the palsy of the left face persisted. Two months after the fourth course of R-CHOP, symptoms of the palsy of the left face progressed and palsy of the right face, double vision, and palsy of the left facialis nerve developed. Then,blepharoptosis of the right eye developed and palsy of the right oculomotorius nerve was observed. MRI showed the presence of trigeminal nerve and oculomotorius nerve swelling but no swelling of the other cranial nerves. Furthermore, skin eruption developed around the left eye.Cytology of this lesion revealed the invasion of lymphoma cells