Nappi O, Ritter J H, Pettinato G, Wick M R
Department of Pathology, Benevento General Hospital, Italy.
Semin Diagn Pathol. 1995 Aug;12(3):221-32.
The tumor designated by Stout and Murray as "hemangiopericytoma" (HPC) more than 50 years ago continues to represent a source of uncertainty and disagreement among pathologists. In particular, questions exist regarding the synonymity of a hemangiopericytomatous growth pattern--defined by a monomorphic population of compact polygonal or bluntly fusiform cells and a branching stromal vascular pattern with a "staghorn" configuration--and the presence of a reproducible biological entity. It has been shown repeatedly that these same histologic features may be observed at least focally in a diversity of neoplasms, including "true" hemangiopericytomas, synovial sarcomas, mesenchymal chondrosarcomas, infantile fibrosarcomas, malignant fibrous histiocytomas, malignant peripheral nerve sheath tumors, leiomyosarcomas, endometrial stromal sarcomas, solitary fibrous tumors, myofibromas, malignant mesotheliomas, thymomas, sarcomatoid carcinomas, malignant melanomas, and "phosphaturic mesenchymal tumors." Despite their potential sharing of the microscopic attributes in question, such neoplasms have individualistic clinical features and can also be distinguished from one another by specialized pathologic analyses. HPC is "defined" in that context by reactivity for vimentin, with or without CD34 and CD57, but it lacks other immunodeterminants of epithelial, neural, and myogenous differentiation. Paradoxically, this phenotype is indeed associated with the presence of myogenous-type cytoplasmic filaments in ultrastructural evaluations of HPC. Other lesions that may resemble "true" HPC--but which possess dissimilar subcellular and clinical characteristics--include solitary fibrous tumors, hemangiopericytomalike tumors of the sinonasal tract, and "infantile (congenital) hemangiopericytomas." Such observations suggest that the hemangiopericytoma is both a pathologic entity and a morphological pattern, and they emphasize the utility of adjuvant pathologic studies in this diagnostic context.
50多年前，被斯托特和默里命名为“血管外皮细胞瘤”（HPC）的肿瘤，至今仍是病理学家们存在不确定性和分歧的根源。特别是，关于血管外皮细胞瘤样生长模式（由紧密排列的多边形或钝梭形单一形态细胞群以及具有“鹿角”构型的分支间质血管模式所定义）与可重复性生物实体的存在之间的同义性问题依然存在。反复研究表明，至少在局灶性病变中，多种肿瘤都可能出现这些相同的组织学特征，包括“真性”血管外皮细胞瘤、滑膜肉瘤、间叶性软骨肉瘤、婴儿纤维肉瘤、恶性纤维组织细胞瘤、恶性外周神经鞘瘤、平滑肌肉瘤、子宫内膜间质肉瘤、孤立性纤维瘤、肌纤维瘤、恶性间皮瘤、胸腺瘤、肉瘤样癌、恶性黑色素瘤以及“伴高磷血症的间叶性肿瘤”。尽管这些肿瘤可能具有上述共同的微观特征，但它们具有各自独特的临床特点，并且也可以通过专门的病理分析相互区分。在这种情况下，HPC通过波形蛋白反应性来“定义”，可伴有或不伴有CD34和CD57，但它缺乏上皮、神经和肌源性分化的其他免疫标志物。矛盾的是，在HPC的超微结构评估中，这种表型确实与肌源性细胞质细丝的存在相关。其他可能类似于 “真性” HPC，但具有不同亚细胞和临床特征的病变包括孤立性纤维瘤、鼻窦血管外皮细胞瘤样肿瘤以及“婴儿（先天性）血管外皮细胞瘤”。这些观察结果表明，血管外皮细胞瘤既是一种病理实体，也是一种形态学模式，并且它们强调了在这种诊断背景下辅助病理研究的实用性。
