Abstract：
Ewing sarcoma is an uncommon neoplasm considered in the differential diagnosis of tumors with \"small round cell\" morphology, but its occurrence in the gynecologic tract has only been sporadically documented. Herein, we describe the largest cohort of Ewing sarcoma localized to the female genital tract to date, and emphasize their clinicopathologic resemblance to more common gynecologic neoplasms. Ewing sarcoma (n=21) was retrospectively identified from 5 institutions. The average patient age was 35 (range 6-61) years. Tumor sites included uterus (n=8), cervix (n=4), vulva (n=5), vagina (n=1), broad ligament (n=1), inguinal area (n=1), and pelvis (n=1). Nine of 18 cases in which slides were available for review demonstrated only classic round cell morphology, with the remainder showing a variable combination and prominence of variant ovoid/spindle or epithelioid appearance. Tumors showed diffuse membranous reactivity for CD99 (20/20) and were positive for NKX2.2 (8/8, diffuse) and cyclin D1 (7/7, of which 3/7 were patchy/multifocal and 4/7 were diffuse). They were negative for ER (0/6) and CD10 (0/6). Three cases were initially diagnosed as endometrial stromal sarcomas. EWSR1 rearrangement was confirmed in 20/21 by fluorescence in situ hybridization (n=15) and/or sequencing (n=8). Of the eight tumors that underwent sequencing, 6 harbored FLI1 , 1 ERG, and 1 FEV as the fusion partner. Of 11 patients with available follow-up, 5 died of disease, 1 developed lung metastases and 5 are alive with no evidence of disease. Ewing sarcoma of the gynecologic tract is a rare, aggressive entity that shares some morphologic and immunohistochemical features with other more common gynecologic neoplasms. In addition to the typical round cell appearance, variant spindled/ovoid to epithelioid morphology may also be observed and should prompt consideration of this entity with appropriate immunohistochemical and/or molecular studies.
摘要：
尤文肉瘤是一种罕见的肿瘤，在与“小圆细胞”形态肿瘤的鉴别诊断中考虑，但它在妇科领域的发生仅有零星记录。在这里，我们描述了迄今为止最大的女性生殖道尤因肉瘤队列，并强调其临床病理与更常见的妇科肿瘤相似。回顾性地从5个机构中鉴定出尤文肉瘤（n=21）。患者平均年龄为35岁（6-61岁）。肿瘤部位包括子宫（n=8），子宫颈（n=4），外阴（n=5），阴道（n=1），阔韧带(n=1),腹股沟区（n=1），和骨盆（n=1）。18例幻灯片可供查阅的病例中有9例仅显示经典的圆形细胞形态，其余的显示可变的组合和突出的变体卵形/纺锤形或上皮样外观。肿瘤对CD99（20/20）表现为弥漫性膜反应性，对NKX2.2（8/8，弥漫性）和细胞周期蛋白D1（7/7，其中3/7为斑片状/多灶性，4/7为弥漫性）阳性。ER(0/6)和CD10(0/6)阴性。3例最初诊断为子宫内膜间质肉瘤。通过荧光原位杂交(n=15)和/或测序(n=8)在20/21中确认EWSR1重排。在接受测序的八个肿瘤中，6个有FLI1，1个ERG，和1FEV作为聚变伙伴。在11名获得随访的患者中，5死于疾病，1例发生肺转移，5例存活，无疾病迹象。妇科尤因肉瘤是一种罕见的，侵袭性实体，与其他更常见的妇科肿瘤具有一些形态学和免疫组织化学特征。除了典型的圆形细胞外观，也可观察到梭状/卵形至上皮样形态的变异,并应提示通过适当的免疫组织化学和/或分子研究来考虑该实体.
