海綿静脈洞に進展した上咽頭癌の1例

A case with nasopharyngeal carcinoma extending into the cavernous sinus

I．はじめに

　上咽頭癌は，局所の腫瘤形成や頸部リンパ節腫脹などを呈する耳鼻科領域の疾患である．初診時に既に転移巣を有する症例が非常に多く全体の70％以上を占め，これがこの疾患の予後不良の一因ともなっている．このように転移しやすいのにかかわらず，連続性に頭蓋底に浸潤することは，非常に近い部位でありながらまれであるとされている．われわれは，外転神経麻痺を呈した患者の海綿静脈洞病変に対して生検を行うことにより，上咽頭癌の存在が判明した症例を経験した，本例は原発部位に肉眼的には病変が認められないのにかかわらず，既に連続性に頭蓋内への進展を示しており，非常にまれであると考えられた．さらにこの症例に対して，手術と放射線治療を行い，寛解をもたらすことが出来たので文献的考察を加え報告する．

Nasopharyngeal carcinoma is seen frequently in South China, but it is rare in Japan as well as in West-ern countries. We reported a rare case with intracranial extension at the initial presentation.

This 25-year-old Japanese female showed left abducens palsy. MRI revealed an intracavernous mass with homogeneous enhancement connected with the le-sion around the epipharynx through the parapharyn-geal space. The mass enlarged gradually, followed by left trigeminal palsy. An elevation of the titer of serum EBV Ig-G was noted. She was operated on via the sub-temporal approach, which revealed an intracavernous tumor, connected with the infratemporal fossa mass via the enlarged foramen ovale. Histological examination of the surgical specimen revealed lymphoepithelioma. Loc-al irradiation of ⁶⁰Co of 63 Gy was performed on the cavernous and parapharyngeal tumors and they de-creased in size remarkably. However, metastasis to the upper right neck lymphnode occurred, and it was re-moved. Additional irradiation of 45 Gy was performed on her neck. Chemotherapy was not able to be carried out due to leucocytopenia. At present, 2 years after onset, no regrowth of the tumor has been seen.

At initial presentation, intracranial extension of nasopharyngeal carcinoma is very rare. Remission may be obtained by a combination of surgery and irradiation even in cases with metastasis.