Hashimoto H, Tsuneyoshi M, Daimaru Y, Enjoji M
Acta Pathol Jpn. 1985 Sep;35(5):1087-98.
This clinicopathologic study concerns 8 cases of extraskeletal Ewing's sarcoma, including electron-microscopic examination of one case. In three patients, autopsy was done. The age of the patients ranged from 12 to 31 years with a median of 16 years. The tumors mainly arose in the soft tissues of the trunk (4 cases) and the lower extremity (3 cases). Histologically, they were made up of closely packed uniform, small cells, arranged in sheets separated by strands of fibrovascular stroma. The tumor cells had round to oval nuclei with finely dispersed chromatin and scanty ill-defined cytoplasm almost invariably containing a fair amount of diastase-digested PAS-positive material. Ultrastructurally, the tumor cells were composed principally of undifferentiated mesenchymal cells, and contained prominent pools of glycogen in the cytoplasm. Aggregates of intermediate filaments were seen in a perinuclear location. These light- and electron-microscopic findings are indistinguishable from those of Ewing's sarcoma of the bone. Differential points from other soft-tissue small round cell sarcomas such as malignant neuroepithelioma (peripheral neuroblastoma), embryonal or alveolar rhabdomyosarcoma were briefly discussed.
本临床病理研究涉及8例骨外尤文肉瘤，其中1例进行了电子显微镜检查。3例患者进行了尸检。患者年龄为12至31岁，中位数为16岁。肿瘤主要发生于躯干软组织（4例）和下肢（3例）。组织学上，肿瘤由紧密排列的形态一致的小细胞构成，呈片状排列，其间有纤维血管间质束分隔。肿瘤细胞核呈圆形至椭圆形，染色质细腻分散，细胞质稀少且界限不清，几乎总是含有相当数量的淀粉酶消化后PAS阳性物质。超微结构上，肿瘤细胞主要由未分化的间充质细胞组成，细胞质内有明显的糖原池。在核周可见中间丝聚集。这些光镜和电镜表现与骨尤文肉瘤难以区分。文中简要讨论了与其他软组织小圆细胞肉瘤如恶性神经上皮瘤（外周神经母细胞瘤）、胚胎性或肺泡状横纹肌肉瘤的鉴别要点。
