Liposarcoma is the most common soft tissue sarcoma in adults; however, accurate diagnosis often depends on the use of ancillary molecular testing which can be time consuming and expensive. Myxoid/round cell liposarcoma may be a diagnostic challenge due to the morphologic similarities with other nonadipocytic sarcomas with round cell morphology. Immunohistochemistry may be a helpful adjunct to appropriately triage cases for molecular testing. Perilipin 1 (PLIN1) and perilipin 2 (adipophilin) (PLIN2) are intracellular proteins involved in lipid droplet formation, which we hypothesized may be useful as immunohistochemical markers for liposarcoma. Using archival tumor tissue, we assessed pattern of PLIN1 and PLIN2 expression in 46 adipocytic tumors and 36 nonadipocytic sarcomas. PLIN1 was expressed in 88% of liposarcomas, including 100% of myxoid/round cell liposarcomas, and did not have any expression in nonadipocytic sarcomas. PLIN1 was not expressed in dedifferentiated liposarcoma. Although PLIN2 demonstrates increased sensitivity for liposarcoma, including expression in dedifferentiated liposarcoma, it is not specific for adipocytic differentiation and is expressed in other nonadipocytic sarcomas. Furthermore, PLIN2 is not expressed in lipoma-like well-differentiated liposarcoma, and as such has limited diagnostic utility.

中文翻译：

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Perilipin 在脂肪肉瘤中的应用

脂肪肉瘤是成人中最常见的软组织肉瘤。然而，准确的诊断通常取决于辅助分子检测的使用，这种检测既费时又费钱。由于与其他具有圆形细胞形态的非脂肪细胞肉瘤的形态学相似性，粘液样/圆形细胞脂肪肉瘤可能是一个诊断挑战。免疫组织化学可能是对分子检测进行适当分类的有用辅助手段。Perilipin 1 (PLIN1) 和perilipin 2 (adipophilin) (PLIN2) 是参与脂滴形成的细胞内蛋白，我们假设它们可用作脂肪肉瘤的免疫组织化学标志物。使用档案肿瘤组织，我们评估了 46 个脂肪细胞肿瘤和 36 个非脂肪细胞肉瘤中 PLIN1 和 PLIN2 的表达模式。PLIN1 在 88% 的脂肪肉瘤中表达，包括 100% 的粘液样/圆形细胞脂肪肉瘤，并且在非脂肪细胞肉瘤中没有任何表达。PLIN1 在去分化脂肪肉瘤中不表达。尽管 PLIN2 显示出对脂肪肉瘤的敏感性增加，包括在去分化脂肪肉瘤中的表达，但它对脂肪细胞分化没有特异性，并且在其他非脂肪细胞肉瘤中表达。此外，PLIN2 在脂肪瘤样分化良好的脂肪肉瘤中不表达，因此诊断效用有限。它对脂肪细胞分化没有特异性，在其他非脂肪细胞肉瘤中表达。此外，PLIN2 在脂肪瘤样分化良好的脂肪肉瘤中不表达，因此诊断效用有限。它对脂肪细胞分化没有特异性，在其他非脂肪细胞肉瘤中表达。此外，PLIN2 在脂肪瘤样分化良好的脂肪肉瘤中不表达，因此诊断效用有限。