原发性小肠腺癌38例临床病理特征分析

Clinicopathologic characteristics of 38 cases of small bowel adenocarcinoma

目的探讨原发性小肠腺癌(small bowel adenocarcinoma,SBA)的临床病理学特征及预后。方法收集北京大学第三医院1999~2020年诊断的38例SBA(壶腹癌除外)的临床病理相关资料,对患者进行随访并复习相关文献。结果38例患者中男性20例,女性18例;年龄28~87岁,中位年龄57.5岁。临床表现为间断性腹痛伴进行性加重(55.2%)、腹胀和呕吐(31.0%)、便血/黑便(13.8%)和乏力(6.9%);位于十二指肠11例(28.9%),空肠17例(44.7%),回肠10例(26.3%);肿瘤大体呈溃疡型或隆起型,仅1例(4%)呈浸润性生长;3例(7.9%)高分化,18例(47.4%)中分化,17例(44.7%)低分化(其中伴有黏液分化4例,伴神经内分泌分化1例,肝样腺癌1例);Ⅰ~Ⅱ期肿瘤21例(58.3%),Ⅲ~Ⅳ期肿瘤15例(41.7%),2例分期不详。16例行错配修复蛋白(mismatch repair protein,MMRP)免疫组化检测,缺失率为25%(4/16)。4例行基因突变检测,1例存在NRAS和PIK3CA突变,1例存在KRAS突变,其余2例未检出突变。15例患者获得随访资料,随访时间7~192个月,中位随访时间22.5个月,其中2例分别于术后17个月和24个月内死亡。结论SBA临床表现缺乏特异性,组织学类型与结直肠癌相似,但具有比结直肠癌更高的MMRP缺失率。该组SBA病例发生于空肠者最多见,患者均无炎症性肠病或乳糜泻病史,不排除与样本量较少有关,有待扩大样本进一步探究。

Purpose To investigate the clinicopathologic features and prognosis of small bowel adenocarcinoma(SBA).Methods A series of 38 cases of SBA diagnosed during 1999 to 2020 at the Third Hospital of Peking University,Beijing,China was collected.Follow-up information was collected and the related literatures were reviewed.Results The series included 20 males and 18 females with ages ranging from 27 to 87 years old(median,57.5 years old).The main clinical symptoms were intermittent abdominal pain with progressive exacerbation(55.2%),abdominal distension and vomiting(31.0%),bloody stool/melena(13.8%)and fatigue(6.9%).Eleven of 38 tumors were located in the duodenum(28.9%),17 in jejunum(44.7%)and 10 in ileum(26.3%).Grossly,the tumors were described as ulcerative or protuberant pattern,only one(4%)tumor showed appearance of diffusely infiltrative type.Microscopically,3 cases(7.9%)were well-differentiated adenocarcinoma,18 cases(47.4%)were moderately differentiated and 17 cases(44.7%)were poorly differentiated(4 cases with mucinous differentiation,1 with neuroendocrine differentiation,1 case was hepatoid adenocarcinoma).Twenty-one cases(58.3%)were in stageⅠ-Ⅱ,15 cases(41.7%)in stageⅢ-Ⅳ,and in 2 cases,the stage information was unavailable.Immunohistochemistry(IHC)for mismatch repair(MMR)proteins was performed in 16 cases,4 cases showed MMR protein deficient.Four cases received KRAS,NRAS,PIK3CA and BRAF mutation analysis,1 of which had NRAS and PIK3CA mutations and 1 had KRAS mutation.Fifteen patients were followed up for 7 to 192 months,and the median follow-up time was 22.5 months.Two patients died of the disease in 17 and 24 months after operation,respectively.Conclusion SBA is a rare tumor lacking of clinical specificity,and histologically similar to colorectal carcinoma but with a higher rate of MMR protein deficiency.Different from the literature reports,in our series,most of the SBAs occurred in the jejunum,without history of Crohn disease or celiac disease.One probable reason maybe the insufficient samples,therefore further studies are needed to confirm these findings.