Biological Significance of Dedifferentiation of Sarcomas

在回顾了在九州大学医学部病理学第二部门登记的1085例软组织肉瘤的显微镜载玻片和临床总结后，我们选择了27例所谓的“分化”软组织肉瘤（DSTS），定义为高或中度分化肉瘤，含有与恶性纤维组织细胞瘤或纤维肉瘤难以区分的额外间变性区域。其中14例（11%）来自128例脂肪肉瘤，6例（6%）来自105例平滑肌肉瘤，5例（13%）来自39例皮肤外软骨肉瘤，2例（2%）来自98例横纹肌肉瘤。除了临床病理研究，我们进行了免疫组化调查的23例和电子显微镜检查的三个。并与32例原发性恶性纤维组织细胞瘤（MFH）进行了比较。所有肿瘤包含额外的不同的间变性部分MFH在传统的光学显微镜下，超微结构，并在α-l-抗胰凝乳蛋白酶和α-l-抗胰蛋白酶的免疫反应性和蓖麻凝集素和刀豆球蛋白凝集素的凝集素组织化学结果的情况下无法区分。DSTS的间变性成分被认为代表未分化间充质细胞的另一克隆的增殖，所述未分化间充质细胞不能沿着除成纤维细胞样细胞、组织细胞样细胞和肌成纤维细胞以外的任何特定谱系分化沿着。这一概念也支持了原发性MFH是一种原始间叶性肿瘤的观点。根据随访资料，DSTS患者预后不良。27例患者中有19例死于肿瘤。

After reviewing the microscopic slides and clinical summaries of a collection of 1085 cases of soft tissue sarcomas registered at the Second Department of Pathology, Kyushu University Faculty of Medicine, we selected 27 instances of so-called "Differentiated" Soft Tissue Sarcoma (DSTS), defined as well or moderately differentiated sarcoma containing additional anaplastic areas indistiguishable from malignant fibrous histiocytoma or fibrosarcoma. These included 14 (11%) selected from 128 liposarcomas, six (6%) from 105 leiomyosarcomas, five (13%) from 39 extraskeletal chondrosarcomas, and two (2%) from 98 rhabdomyosarcomas. In addition to the clinicopathologic study, we conducted an immunohistochemical survey of 23 cases and an electron microscopic examination of three. The findings were compared with observations of 32 cases of de novo malignant fibrous histiocytoma (MFH). All tumors contained additional distinct anaplastic portions indistinguishable from MFH under conventional light microscopy, ultrastructurally, and in cases of immunoreactivity for alpha-l-antichymotrypsin and alpah-l-antitrypsin and on lectin histochemical findings for ricinus communis agglutinin and concanavalin agglutinin. The anaplastic components of DSTS are presumed to represent the proliferation of another clone of undifferentiated mesenchymal cells that fail to differentiate along any specific lineage other than fibroblast-like cells, histiocyte-like cells, and myofibroblasts. This concept alsoleads to the proposal that de novo MFH is a primitive mesenchymal tumor without any specific differentiation.According to follow-up data, the prognosis of patients with DSTS was ominous. Nineteen of the 27 patients died of the tumor.