三叉神経に沿って頭蓋外に進展した頭蓋内原発悪性リンパ腫の1例

Perineural Spreading along the Trigeminal Nerve in a Patient with Primary Intracranial Malignant Lymphoma : a case report

I．はじめに

　頭蓋内原発悪性リンパ腫が頭蓋外へ転移，進展することは稀な病態であり，報告例も少ない．一方，nasopharyngeal tumorが脳神経に沿って進展し，頭蓋底孔を経由して頭蓋内に侵入するperi-neural tumorは耳鼻咽喉科領域では必ずしも稀ではないが，逆に頭蓋内から頭蓋外に進展したperineural tumorは報告例も少なく，稀な病態と思われる．今回われわれは頭蓋内原発悪性リンパ腫がMeckel's caveに再発した後，三叉神経の3枝に沿って頭蓋外に進展し，各々の末梢部にて腫瘤を形成した稀な1例を経験したので，若干の文献的考察を加え報告する．

We report a rare primary intracranial malignant lymphoma which spread along the trigeminal nerve through the skull base foramen. The patient was a 50-year-old woman, who was diagnosed as having a primary intracranial malignant lymphoma in the right temporal lobe and had undergone an operation and radiation 5 years previously. The tumor was reduced in size and no recurrent tumor could be detected for 5 years. The patient complained of left face swelling and CT scan revealed a large mass in the pterygopala-tine fossa. MRI revealed the recurrent tumor in the left Meckel's cave with extension into the cavernous sinus. The tumor extended through the foramen ovale into the pterygopalatine fossa, through the superior orbital fissure into the orbital cavity and through the infraorbital fossa into the face subcutaneously. Biop-sy of the subcutaneous tumor was carried out and the pathological diagnosis was malignant lymphoma, B cell type, which was identical with the initial tumor. MRI revealed the enlarged trigeminal nerve and 3D-CT revealed the enlargement of the infraorbital fossa and the foramen ovale. We suspected that primary intracranial malignant lymphoma had recurred in the left Meckel's cave and the tumor had spread along the peripheral three divisions of the trigeminal nerve. Perineural spreading along the trigeminal nerve pas-sing through the skull base in patients with nasopharyngeal carcinoma is not rare, but this rarely occurs in the case of intracranial tumors.