Department of Pathology and Laboratory Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
Mod Pathol. 2013 Sep;26(9):1204-10. doi: 10.1038/modpathol.2013.65. Epub 2013 Apr 19.
Myxoid and round cell liposarcomas constitute approximately one-third of all liposarcomas, a relatively common group of fat-derived soft tissue sarcomas. The histomorphology is a continuum between highly differentiated myxoid and poorly differentiated round cell components. The gold standard of diagnosis is dependent on histomorphology and/or identification of t(12;16)(q13;p11) translocation by cytogenetics or demonstration of DDIT3 rearrangements by fluorescence in situ hybridization. There are currently no diagnostic immunohistochemical stains available. The broad range of myxoid neoplasms in the differential diagnosis includes a variety of sarcomas. Given the notable differences in disease biology among myxoid neoplasms, which range from benign to aggressive, an accurate diagnosis is imperative for proper treatment and prognostication. Prompted by our recent study showing frequent expression of the cancer testis antigen NY-ESO-1 in myxoid and round cell liposarcomas, we sought to evaluate the utility of NY-ESO-1 as an immunohistochemical marker for myxoid and round cell liposarcoma among mesenchymal myxoid neoplasms within the differential diagnosis. Formalin-fixed, paraffin-embedded blocks were obtained for the following mesenchymal myxoid neoplasms (n=138): myxoid and round cell liposarcoma (n=38); well-differentiated liposarcoma (n=12); lipoma (n=20; 4 with myxoid change); extra-cardiac soft tissue myxoma (n=39); extraskeletal myxoid chondrosarcoma (n=12); myxofibrosarcoma (n=10: 5 low grade, 2 intermediate grade, 3 high grade); and low-grade fibromyxoid sarcoma (n=7). Utilizing standard immunohistochemistry protocols, full sections were stained with NY-ESO-1 (clone E978), and staining was assessed for intensity (1-2+), percentage of tumor positivity, and location. In all, 36/38 (95%) of the myxoid and round cell liposarcomas demonstrated NY-ESO-1 immunoreactivity. The majority of the positive cases (34/36; 94%) showed strong, homogenous staining (>50% tumor positivity), and two cases (6%) showed weak (1+ intensity), patchy staining (20-30% tumor positivity). Immunoreactivity was predominantly cytoplasmic. All the other neoplasms evaluated were negative for NY-ESO-1. NY-ESO-1 appears to be a sensitive and a specific marker for myxoid and round cell liposarcoma among mesenchymal myxoid neoplasms. The assessment of NY-ESO-1 expression by immunohistochemistry in the appropriate setting provides a cheaper, faster, and more accessible confirmatory test.
黏液样和圆形细胞脂肪肉瘤约占所有脂肪肉瘤的三分之一，是一种相对常见的脂肪源性软组织肉瘤。组织形态学是高度分化的黏液样和低度分化的圆形细胞成分之间的连续体。诊断的金标准依赖于组织形态学和/或细胞遗传学中 12；16(q13;p11)易位的识别或通过荧光原位杂交显示 DDIT3 重排。目前尚无诊断免疫组织化学染色可用。在鉴别诊断中，广泛的黏液样肿瘤包括各种肉瘤。鉴于黏液样肿瘤的疾病生物学差异显著，从良性到侵袭性不等，准确的诊断对于正确的治疗和预后至关重要。鉴于我们最近的研究表明，在黏液样和圆形细胞脂肪肉瘤中经常表达癌症睾丸抗原 NY-ESO-1，我们试图评估 NY-ESO-1 作为黏液样和圆形细胞脂肪肉瘤在鉴别诊断中的间叶性黏液样肿瘤中的免疫组织化学标志物的效用。为以下间叶性黏液样肿瘤获得福尔马林固定、石蜡包埋块（n=138）：黏液样和圆形细胞脂肪肉瘤（n=38）；高分化脂肪肉瘤（n=12）；脂肪瘤（n=20；4 例有黏液样改变）；心脏外软组织黏液瘤（n=39）；骨外黏液样软骨肉瘤（n=12）；黏液纤维肉瘤（n=10：5 级低分化，2 级中级，3 级高级）；和低度纤维黏液样肉瘤（n=7）。使用标准免疫组织化学方案，对 NY-ESO-1（克隆 E978）进行全切片染色，并评估染色强度（1-2+）、肿瘤阳性百分比和位置。总共，38 例黏液样和圆形细胞脂肪肉瘤中的 36 例（95%）显示 NY-ESO-1 免疫反应性。大多数阳性病例（34/36；94%）显示强、均匀染色（>50%肿瘤阳性），2 例（6%）显示弱阳性（1+强度）、斑片状染色（20-30%肿瘤阳性）。免疫反应性主要为细胞质。评估的所有其他肿瘤均为 NY-ESO-1 阴性。NY-ESO-1 似乎是间叶性黏液样肿瘤中黏液样和圆形细胞脂肪肉瘤的一种敏感且特异的标志物。在适当的环境下通过免疫组织化学评估 NY-ESO-1 的表达提供了一种更便宜、更快、更容易获得的确认性测试。
