虫垂癌の臨床病理学的解析

Clinicopathologic Characterization of the Appendiceal Carcinomas

要旨　1995年～2012年3月の17年間に外科的に切除された虫垂腫瘍19例（低異型度粘液性腫瘍3例，分化型腺癌1例，粘液癌1例，低分化腺癌1例，粘液性囊胞腺癌11例，杯細胞カルチノイド2例）を対象とし，臨床病理学的因子の抽出および粘液形質，ミスマッチ修復遺伝子発現低下を免疫組織学的に検討した．粘液性囊胞腺癌の82％が，MUC2，MUC5AC陽性，胃腸混合型の粘液形質を有していたが，ほかの腫瘍でMUC5AC陽性例は認められなかった．また，ミスマッチ修復遺伝子発現低下を粘液性囊胞腺癌で3例認めた．粘液形質の観点から，粘液性囊胞腺癌はほかの癌あるいは低異型度粘液性腫瘍とは大きく異なった腫瘍である可能性があり，また，粘液性囊胞腺癌の一部はserrated neoplasia pathwayを介した癌化経路を有する可能性が示された．

　We reviewed 19 appendiceal carcinomas（3 low-grade appendiceal neoplasms, 1differented adenocarcinoma, 1mucinous carcinoma, 1poorly differented adenocarcinoma, 11mucinous cystadenocarcinomas and 2goblet cell carcinoids）that had been resected surgically between 1995 and 2012. An immunohistochemical panel of MUCs（mucin core peptides）and CD10 was performed. In addition, decreased expression of DNA mismatch repair protein was analyzed immunohistochemically. The results showed that 9/11（82％）mucinous cystadenocarcinomas had gastrointestinal-mixed phenotype, that is, immunopositive for MUC5AC and MUC2. In contrast, low-grade appendiceal neoplasms, adenocarcinoma, and goblet cell carcinoids were immunonegative for MUC5AC. These results indicate that appendiceal mucinous cystadenomas may be distinct tumors that have gastrointestinal phenotype frequently, and some of these cancers may develop through the serrated neoplasia pathway.