Department of Diagnostic Pathology, Chiba University Graduate School of Medicine,1-8-1 Inohana, Chuo-ku, Chiba, Japan.
Am J Surg Pathol. 2013 May;37(5):772-9. doi: 10.1097/PAS.0b013e31828e5168.
Adamantinoma-like Ewing family tumor (EFT) is a rare subset of EFTs showing mixed features of Ewing sarcoma and adamantinoma of the long bones. All currently reported cases of the adamantinoma-like type have been associated with bone. Recently, a unique type of EFT was reported showing complex epithelial differentiation associated with the vagus nerve. Here we describe another unique type of EFT arising in the soft tissue of the neck associated with the vagus nerve. An 11-year-old girl presented to our hospital with a neck tumor on her right side. Surgical resection was performed, and histopathologic examination demonstrated a high-grade malignant neoplasm. The tumor was composed of sheets of small round proliferating cells, basaloid tumor nests with marked squamous differentiation, biphasic growth pattern with epithelioid tumor nests, and spindle cell proliferation. Immunohistochemically, the tumor cells showed diffuse expression of CD99 and FLI-1. In addition, small round cells and basaloid/squamoid components were immunoreactive for AE1/AE3, CAM5.2, cytokeratin 5/6, high-molecular weight keratin, p63, and p40 (ΔNp63). Reverse transcription polymerase chain reaction and direct sequencing analysis revealed that the tumor harbored a t(11;22) translocation, involving EWSR1 and FLI-1, which are characteristic of EFTs. According to these findings, our case has characteristics of both a subset of adamantinoma-like EFT and EFT with complex epithelial differentiation. We suggest that EFT with complex epithelial differentiation is in a common spectrum with the adamantinoma-like type and that adamantinoma-like EFTs can arise in soft tissue, leading to difficulty in differential diagnosis with malignant epithelial tumors.
类似于造釉细胞瘤的尤文家族肿瘤（EFT）是一种罕见的尤文肉瘤，其混合了 Ewing 肉瘤和长骨造釉细胞瘤的特征。所有目前报道的造釉细胞瘤样病例均与骨有关。最近，报道了一种独特类型的 EFT，其表现出与迷走神经相关的复杂上皮分化。在此，我们描述了另一种发生在迷走神经附近的颈部软组织中的独特类型的 EFT。一名 11 岁女孩因右侧颈部肿瘤就诊于我院。行手术切除，组织病理学检查显示为高级别恶性肿瘤。肿瘤由小圆形增生细胞片、具有明显鳞状分化的基底细胞瘤巢、上皮样肿瘤巢的双相生长模式和梭形细胞增生组成。免疫组织化学染色显示肿瘤细胞弥漫表达 CD99 和 FLI-1。此外，小圆细胞和基底样/鳞状成分免疫反应性表达 AE1/AE3、CAM5.2、细胞角蛋白 5/6、高分子量角蛋白、p63 和 p40（ΔNp63）。逆转录聚合酶链反应和直接测序分析显示肿瘤存在 t(11;22)易位，涉及 EWSR1 和 FLI-1，这是 EFT 的特征。根据这些发现，我们的病例既有类似于造釉细胞瘤的 EFT 子集的特征，也有复杂上皮分化的 EFT 特征。我们认为具有复杂上皮分化的 EFT 与造釉细胞瘤样类型具有共同的特征，并且造釉细胞瘤样 EFT 可发生在软组织中，导致与恶性上皮肿瘤的鉴别诊断困难。
