非典型脂肪瘤/高分化脂肪肉瘤和去分化脂肪肉瘤的特征性分子特征是源自染色体 12q13-15 的扩增序列，包括 MDM2 原癌基因 (MDM2)。由于非典型脂肪瘤/分化良好的脂肪肉瘤进展为更具侵袭性的去分化脂肪肉瘤可能对患者的预后产生不利影响，因此评估后者的程度可能很重要。 调查临床病理特征（包括肿瘤大小）之间的相关性，修改了国家癌症防治中心联盟 (FNCCLCC) 的分级、分子数据和 123 例手术切除的 MDM2 扩增脂肪肉瘤的结果。对病理报告和临床记录进行了审查。使用对数秩检验来比较生存趋势，并进行单变量逻辑回归来识别与不良事件（远处转移和/或死亡）相关的变量，从中导出P值以构建多元回归模型。单变量分析、去分化成分的最大单一维度、获得 12 号染色体的细胞百分比、有丝分裂计数以及 3 级改良 FNCLLC 的存在与不良事件相关。在多变量分析中，去分化成分的最大单一维度（比值比：1.169；95% CI：1.053, 1.299；P = .003），以及更高的有丝分裂计数（比值比：1.133；95% CI：1.037, 1.237） ; P = .006) 与不良事件相关。当前局部复发状态、总体最大肿瘤尺寸、总体肿瘤体积、MDM2 拷贝数或 MDM2 与 12 号染色体着丝粒探针比率与不良结果之间没有统计学显着关联。根据去分化成分的大小对去分化脂肪肉瘤进行分期可以更好地预测结果。©​​ 2024 美国病理学家学院。

The characteristic molecular signature for both atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma is amplified sequences derived from chromosome 12q13-15, including MDM2 proto-oncogene (MDM2). As the progression of atypical lipomatous tumor/well-differentiated liposarcoma to the more aggressive dedifferentiated liposarcoma has the potential to adversely affect patient outcomes, the extent of the latter component might be important to evaluate.To investigate the correlation between clinicopathologic characteristics, including tumor size, modified Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade, molecular data, and outcomes in 123 surgically resected MDM2-amplified liposarcomas.Pathology reports and clinical records were reviewed. A log-rank test was used to compare the survival trends, and univariate logistic regression was performed to identify variables associated with adverse events (distant metastasis and/or death), from which the P value was derived to construct a multivariate regression model.In univariate analysis, the largest single dimension of the dedifferentiated component, the percentage of cells with gain of chromosome 12, mitotic count, and the presence of modified FNCLLC grade 3 were associated with adverse events. In multivariate analysis, the largest single dimension of the dedifferentiated component (odds ratio: 1.169; 95% CI: 1.053, 1.299; P = .003), and a higher mitotic count (odds ratio: 1.133; 95% CI: 1.037, 1.237; P = .006) were correlated with adverse events. There was no statistically significant association between current local recurrence status, overall largest tumor dimension, overall tumor volume, MDM2 copy number, or MDM2 to chromosome 12 centromere probe ratio and adverse outcomes.Staging dedifferentiated liposarcoma based on the size of the dedifferentiated component better predicts the outcome.© 2024 College of American Pathologists.