罕见生长方式的原发性腹膜恶性肿瘤临床病理观察

Primary peritoneal malignant tumor with rare growth pattern: a clinical and pathological investigation

目的探讨2例肠腔内呈内生性生长这一罕见生长方式的原发性腹膜恶性肿瘤的临床病理特点、免疫表型、诊断及鉴别诊断。以提高对这种生长方式的腹膜原发恶性肿瘤的认识。方法对2例肠腔内呈内生性生长的原发性腹膜恶性肿瘤的临床资料、病理形态,免疫组织化学特点进行回顾性分析,并复习相关文献。结果 1例为第二苗勒系统来源高级别浆液性癌,1例为局限性腹膜恶性间皮瘤,2例均有着类似于肠癌的生长方式,突向并部分阻塞肠腔,病灶均为单发的肠腔内内生性肿物,镜下均可见肿物均主要位于浆膜层,累及肌层、黏膜下层及黏膜层,但均未突破浆膜层。第二苗勒系统浆液性癌者呈高级别癌,细胞形态相对单一,免疫组织化学显示:雌激素受体(ER)阳性、配对盒基因8(PAX8)阳性、P16阳性;恶性间皮瘤者细胞呈双向分化,有上皮样型细胞和肉瘤样型细胞组成。免疫组织化学染色显示:广谱细胞角蛋白(AE1/AE3)阳性、钙结合蛋白阳性、波形蛋白阳性、细胞角蛋白5/6(CK5/6)阳性、肾母细胞瘤基因1(WT-1)阳性。结论肠腔内呈内生性生长的局限性腹膜恶性间皮瘤及第二苗勒系统来源的浆液性癌较为罕见,临床表现无特异性,影像学及术中所见均呈单发的肠腔内生性肿物,阻塞部分肠腔,其余盆腹腔未见肿瘤累及,组织形态及免疫组织化学表型无绝对特异性,临床及病理容易误诊。确诊主要依靠病理组织学形态及免疫表型,且需与有类似生长方式、组织学形态及免疫组织化学表达方式的肿瘤相鉴别。

Objective To investigate the clinical and pathological features, immune phenotype, diagnosis, and differential diagnosis of the primary peritoneal malignant tumor with rare growth pattern, which were intestinal en-dogenous growth in 2 cases, and to improve the recognition of the primary peritoneal malignant tumor with rare growth pattern. Methods The clinical data, pathological morphology and immune phenotype of the primary peritoneal malig-nant tumor with intestinal endogenous growth in the 2 cases were retrospectively analyzed, and the related literatures were reviewed. Results The 2 cases included a high grade serous carcinoma（HGSC） originated from the second Müllerian system and a localized peritoneal malignant mesothelioma, which had similar growth pattern of intestinal cancer and partially obstructed the intestine. Microscopically, the lesions were single intestinal endogenous tumor,which were mainly in the serous membrane layer, involving the muscle layer, submucosa and mucous membrane layer,without breaking the serous membrane layer. The cell morphology in the patient with HGSC originated from the sec-ond Müllerian system was relatively simple. The immunohistochemistry showed： positive ER, positive PAX8 and posi-tive P16; the cells in the patient with malignant mesothelioma showed bi-directional differentiation. The immunohistochemical staining showed： positive AE1/AE3, positive calretinin, positive vimentin, positive CK5/6, and positive WT-1.Conclusion The intestinal endogenous growth of the localized peritoneal malignant mesothelioma and the HGSC o-riginated from the second Müllerian system is rare, without specific clinical features. The imaging and intraoperative findings show that the single intestinal endogenous tumor partially obstructs the intestine. However, no tumors and no absolutely specific morphology and immunohistochemical phenotype are found in the rest of the abdominopelvic cavi-ty. Its diagnosis is mainly based on histopathology, morphology and phenotype, and the identification of a similar growth pattern, tumor histology and immunohistochemical expression of tumor.