结肠肝样腺癌临床病理分析

Clinicopathological features of hepatoid adenocarcinoma of colon

目的探讨结、直肠肝样腺癌(HAC)的临床病理特点、诊断和鉴别诊断要点以及治疗和预后。方法报道1例发生于乙状结肠的肝样腺癌,观察其组织形态特点及免疫组化结果,并结合相关文献复习,总结该类肿瘤的临床病理特点及预后。结果患者男性,31岁。乙状结肠隆起型肿物,大小4 cm×3 cm×2.5 cm。镜下见低分化腺癌,肿瘤全部为肝样分化区域,无典型腺癌区域;瘤细胞在肠壁内弥漫浸润性生长,大部分区域呈实性片状分布,细胞中等大小,分化差,异型性明显,胞质淡嗜伊红色,部分核呈空泡状,核仁明显,似幼稚的肝细胞,可见瘤巨细胞;部分区域瘤细胞排列呈梁索样,细胞多角形,胞质嗜酸性,核仁明显,似肝细胞癌,胞质内外可见散在分布、数量不多、大小不一的圆形或卵圆形淡嗜酸性均质半透明体;局部瘤细胞分化极差,核分裂象多见,局灶>20个/HPF,局灶见假菊形团样结构;肿瘤间质局部血管丰富,可见坏死及广泛脉管内癌栓,并见脂肪变性。免疫组化:肿瘤细胞CK及CK18(+),vimentin、SALL4部分(+),GPC-3灶状(+),GATA-3、Villin小灶(+);CK20、CDX-2、p504S、PSA、CK7、PAX-8、CD56、Syn、CgA、Dog-1、CD117、S-100、CD30、Desmin、Myo-D1、TFE-3、SMA、Melan-A、Calretinin、D2-40、WT-1、HMB45、h-caldesmon、Hepatocyte、FIL-1、hCG及AFP(-);LCA(-,淋巴细胞+),CD34(-,血管+),CD31(-,血管+);Ki-67阳性指数25%。特殊染色:肿瘤细胞PAS(+)。最终诊断:乙状结肠肝样腺癌。结论结、直肠肝样腺癌是一种罕见类型的腺癌,是结、直肠腺癌中的一种特殊亚型,具有独特的组织形态特点,免疫组化有助于明确诊断及与转移性肝细胞癌、卵巢肝细胞样癌、肝细胞型卵黄囊瘤及胎儿型胃肠道腺癌等鉴别。该肿瘤转移及复发率高,预后差,应手术扩大切除并进行必要的区域淋巴结清扫,术后放、化疗效果不明确。目前对该病认识不足,易误诊,需加强对该病的认识。

Objective To investigate the clinicopathological features,diagnosis,differential diagnosis,treatment and prognosis of colorectal hepatoid adenocarcinoma(HAC).Methods A case of hepatoid adenocarcinoma in sigmoid colon was reported.The histological features and immunohistochemical results were observed.The clinicopathological features and prognosis of this type of adenocarcinoma were summarized by reviewing the relevant literature.Results The patient was a 31-year-old male.The size of sigmoid protuberant mass was 4×3×2.5 cm.Microscopically,there were poorly differentiated adenocarcinomas,which were hepatoid-like and no typical adenocarcinomas.Tumor cells grew diffusely in the intestinal wall,most of which were solid and patchy distribution.The cells were medium-sized,poorly differentiated,with obvious atypia,light eosinophilic red cytoplasm,vacuoles in some nuclei,obvious nucleoli.In some areas,the tumor cells were arranged in a trabecular pattern,with polygonal cells,eosinophilic cytoplasm and prominent nucleoli,resembling hepatocellular carcinoma,and scattered round or oval light eosinophilic translucent bodies with small number and different sizes were seen inside and outside the cytoplasm.Most of the tumors had more than 20 mitotic figures per HPF and pseudorosette-like structures.There were abundant blood vessels in the stroma of the tumors,necrosis and extensive intravascular tumor thrombus,and steatosis.Immunohistochemical staining showed that tumor cells were positive for CK and CK18;partially positive for vimentin,SALL4,GPC-3,GATA-3 and villin;but negative for CK20,CDX-2,p504S,PSA,CK7,PAX-8,CD56,Syn,CgA,Dog-1,CD117,S-100,CD30,Desmin,Myo-D1,TFE-3,SMA,Melan-A,Calretinin,D2-40,WT-1,HMB45,h-caldesmon,Hepatocyte,FIL-1,hCG,AFP,LCA,CD34 and CD31.The positive index of Ki-67 was 25%.Special staining showed PAS(+)of tumor cells.Final diagnosis was hepatoid adenocarcinoma of sigmoid colon.Conclusion Colorectal hepatoid adenocarcinoma is a rare type of adenocarcinoma.It is a special subtype of colorectal adenocarcinoma.It has unique histomorphological characteristics.Immunohistochemistry is helpful in definite diagnosis and differentiation from metastatic hepatocellular carcinoma,ovarian hepatocellular carcinoma,hepatocellular yolk sac tumor and fetal gastrointestinal adenocarcinoma.Because of its high metastasis and recurrence rate and poor prognosis,extensive resection and necessary regional lymph node dissection should be performed.The effect of radiotherapy and chemotherapy after operation is not clear.At present,the knowledge of this disease is insufficient and easy to be misdiagnosed.It is necessary to strengthen the understanding of this disease.