胸膜高分化乳头状间皮瘤临床病理观察

Clinicopathological features and differential diagnosis of well-differentiated papillary mesothelioma

目的探讨高分化乳头状间皮瘤的临床病理学特点和鉴别诊断。方法回顾复习1例高分化乳头状间皮瘤的临床资料、组织学形态和免疫组化表型结果。结果患者女性,63岁。间断胸闷、憋气2周。胸腔镜见右胸腔壁层、脏层灰白色弥漫性散在结节,直径0.2～1cm。巨检:淡黄色片状组织2块,总体积2.5cm×1.5cm×0.2cm大小;镜检:肿瘤由乳头状结构组成,乳头表面被覆单层立方上皮样细胞,其中纤维组织和血管轴心构成乳头,其大小和形态较一致。核呈圆形或卵圆形,位于细胞中央,染色质匀细,核仁不明显,无核分裂象;胞质中等量,嗜伊红色。部分乳头表面上皮样细胞呈巢状及片状增生并向间质中相互吻合,形成索状、梁状、腺样和迷路样结构,异型性不明显。免疫组化:mesothelial cell(),vimentin(+),Ki-67阳性细胞约20%。结论高分化乳头状间皮瘤是一种罕见的低度恶性潜能的间皮肿瘤,可被误诊为恶性间皮瘤、孤立性纤维性肿瘤、转移性腺癌、交界性浆液性肿瘤、腺瘤样瘤等肿瘤。

Objective To study the clinicopathologic feature and differential diagnosis of well-differentiated papillary mesothelioma （WDPM）. Methods The clinical data and histological immunohistochemical feature were analyzed in 1 case of WDPM. Results A female, 63-years-old, presented with symptom of chest pain and dyspnea for two weeks. According to thoracoscopy, some grey nodules of 0. 2 - 1 cm in diameter were found and these were diffusely scattered in right viscerals and parietal pleura. Macroscopically, two pieces of light yellow flaplike tissues, 2. 5 cm×1.5 cm×0. 2 cm in size, were presented. Microscopically, the tumor was composed of papillary structures covered with single layer of cuboie epithelioid cells that were in same size and morphology with fiber-vascular cores. The nucleus was circular or oval, centrally-located with fine chromatin, obscure nucleolus without mitosis, and eosin-stained and middle-sized cytoplasm. Part of papillae were covered with hyperplastic epitheloid cells in nests and sheets which anastomosized with each other in the stromal tissue and had sheet, fasciculated, tubular and netieulated patterns. Dysplasia was rather mild. Immunohistochemically, mesothelial cells were positive to vimentin, and the positive rate of Ki67 was 20%. Conclusion WDPM is thought to be a low malignant and uncommon tumor, and it is often misdiagnosed as malignant mesosthelioma, solitary fibrous tumor, metastatic adenocarcinoma, boderline malignant serous tumor and adenomatoid tumor.