虫垂病変の臨床―腹膜偽粘液腫の診断および治療方針

Diagnosis and Treatment of Pseudomyxoma Peritonei

要旨　腹膜偽粘液腫はまれな疾患で，典型的には低異型度虫垂粘液癌が穿孔し，腹腔内に多量の粘液が貯留する．血行性・リンパ行性転移を来すことはまれだが，放置すると次第に進行し，致死的となる．病理学的にも臨床的にもlow-gradeとhigh-gradeに分類されることが多いが，その生物学的悪性度は広い幅を有する．虫垂粘液腫瘤の非穿破例においては，診断と治療を兼ねた早期の切除が望まれる．腹膜偽粘液腫に対しては，腹膜切除を伴う完全減量切除と術中腹腔内温熱化学療法の組み合わせが，今や標準治療として確立している．わが国においても今後，センター化による症例の蓄積を図ることにより，病態のさらなる解明と治療成績の向上が望まれる．

　Pseudomyxoma peritonei is a rare clinical entity characterized by mucinous ascites that most commonly originates from a low-grade mucinous adenocarcinoma of the appendix. It is progressive and can be fatal if untreated ; however, bloodborne or nodal metastasis is uncommon. The behavior of mucinous tumors suggests that they are, at best, a borderline malignancy with a spectrum of pathology ranging from indolent to aggressive mucinous adenocarcinoma. Because tumors limited to the appendiceal wall can be cured by complete excision, it generally considered appropriate to classify them as adenomas and early removal should be recommended. Tumors with extra-appendiceal neoplastic epithelium are classified as mucinous adenocarcinomas and subcategorized as low- or high-grade. Complete cytoreduction combined with hyperthermic intraperitoneal chemotherapy is now considered the standard of care, despite its associated morbidity.