Abstract：
EWSR1::POU2AF3 (COLCA2) sarcomas are a recently identified group of undifferentiated round/spindle cell neoplasms with a predilection for the head and neck region. Herein, we report our experience with 8 cases, occurring in 5 men and 3 women (age range, 37-74 years; median, 60 years). Tumors involved the head/neck (4 cases), and one each the thigh, thoracic wall, fibula, and lung. Seven patients received multimodal therapy; 1 patient was treated only with surgery. Clinical follow-up (8 patients; range, 4-122 months; median, 32 months) showed 5 patients with metastases (often multifocal, with a latency ranging from 7 to 119 months), and 3 of them also with local recurrence. The median local recurrence-free and metastasis-free survival rates were 24 months and 29 months, respectively. Of the 8 patients, 1 died of an unknown cause, 4 were alive with metastatic disease, 1 was alive with unresectable local disease, and 2 were without disease. The tumors were composed of 2 morphologic subgroups: (1) relatively bland tumors consisting of spindled to stellate cells with varying cellularity and fibromyxoid stroma (2 cases) and (2) overtly malignant tumors composed of nests of \"neuroendocrine-appearing\" round cells surrounded by spindled cells (6 cases). Individual cases in the second group showed glandular, osteogenic, or rhabdomyoblastic differentiation. Immunohistochemical results included CD56 (4/4 cases), GFAP (5/8), SATB2 (4/6), keratin (AE1/AE3) (5/8), and S100 protein (4/7). RNA sequencing identified EWSR1::POU2AF3 gene fusion in all cases. EWSR1 gene rearrangement was confirmed by fluorescence in situ hybridization in 5 cases. Our findings confirm the head/neck predilection and aggressive clinical behavior of EWSR1::POU2AF3 sarcomas and widen the morphologic spectrum of these rare lesions to include relatively bland spindle cell tumors and tumors with divergent differentiation.
摘要：
EWSR1：：POU2AF3：（COLCA2）肉瘤是最近发现的一组未分化的圆形/梭形细胞肿瘤，对头颈部区域有好感。在这里，我们报告了我们8例的经验，发生在5名男性和3名女性（年龄范围：37-74岁；中位数60岁）。肿瘤累及头颈部（4例），大腿各一个，胸壁,腓骨和肺。7名患者接受了多模式治疗，一名患者仅接受手术治疗。临床随访（8例；范围4-122个月；中位数：32个月）显示5例转移患者（通常为多灶性，延迟范围为7-119个月)，其中3例伴有局部复发。中位无局部复发和无转移生存率分别为24个月和29个月。分别。在这8名患者中,1人死于不明原因,4人患有转移性疾病，1例有不可切除的局部疾病，2例无疾病。肿瘤由2个形态学亚组组成：1）相对温和的肿瘤，由具有不同细胞组成的星状细胞和纤维黏液样基质（2例）和2）明显的恶性肿瘤，由“神经内分泌出现的圆形细胞包围的巢状细胞（6例）。第2组个别病例呈腺体，成骨或横纹肌母细胞分化。免疫组织化学结果包括：CD56（4/4例），GFAP(5/8)SATB2(4/6),角蛋白（AE1/AE3）（5/8）和S100蛋白（4/7）。RNA测序在所有情况下鉴定了EWSR1::POU2AF3基因融合。5例经FISH证实EWSR1基因重排。我们的发现证实了EWSR1::POU2AF3肉瘤的头颈部好感和侵袭性临床行为，并扩大了这些罕见病变的形态范围，包括相对温和的梭形细胞肿瘤和分化不同的肿瘤。
