腹腔及腹膜后脂肪肉瘤CT影像、病理及免疫组化特征分析及研究进展

CT Imaging, Pathological and Immunohistochemical Features of Abdominal and Retroperitoneal Liposarcoma and Research Progress

摘要: 目的：分析腹腔及腹膜后脂肪肉瘤(LPS)的CT影像、病理及免疫组化核心特征，探究术前误诊原因及亚型影像差异，为临床精准诊疗提供依据。方法：回顾性分析43例经手术病理确诊的腹腔及腹膜后LPS患者的临床、多层螺旋CT及病理免疫组化资料，量化统计各亚型CT影像指标，对比不同病理亚型影像差异，通过Logistic回归分析术前误诊为胃肠道间质瘤(GIST)的危险因素。结果：本组患者以50~79岁中老年男性为主，肿瘤体积普遍偏大，病理亚型以去分化脂肪肉瘤(DDLPS, 65.1%)占绝对主导。量化CT分析显示本组以乏脂肪病灶(62.8%)为主，DDLPS与高分化脂肪肉瘤(WDLPS)在平扫CT值、脂肪占比方面存在显著统计学差异(P = 0.003, P = 0.022)，钙化仅见于DDLPS。免疫组化CDK4、P16、Vimentin、Ki-67阳性率100%，DDLPS的Ki-67增殖指数显著高于WDLPS (P < 0.001)。本组LPS术前CT精准诊断率仅9.3%，误诊GIST发生率达30.2%，以DDLPS、乏脂肪病灶误诊为主，传统单一CT征象无法独立解释误诊风险。结论：腹腔及腹膜后LPS异质性强、术前误诊率高，平扫CT值联合脂肪占比可无创鉴别WDLPS与DDLPS，MDM2/CDK4/P16三联免疫组化联合Ki-67可精准完成病理诊断及恶性程度分层。传统CT诊断存在固有局限，联合分子病理与影像组学可有效提升术前诊断精准度，指导临床个体化治疗。

Abstract: Objective: To analyze the core CT imaging, pathological and immunohistochemical features of abdominal and retroperitoneal liposarcoma (LPS), explore the causes of preoperative misdiagnosis and imaging differences among different subtypes, and provide evidence for clinical accurate diagnosis and treatment. Methods: The clinical, multi-slice spiral CT, pathological and immunohistochemical data of 43 patients with surgically and pathologically confirmed abdominal and retroperitoneal LPS were retrospectively analyzed. Quantitative CT imaging indicators of each subtype were statistically analyzed, imaging differences among different pathological subtypes were compared, and Logistic regression was used to analyze the risk factors for preoperative misdiagnosis as gastrointestinal stromal tumor (GIST). Results: The patients were mainly middle-aged and elderly males aged 50~79 years with generally large tumor volumes. Dedifferentiated liposarcoma (DDLPS, 65.1%) was the dominant pathological subtype. Quantitative CT analysis showed that 62.8% of the lesions were fat-poor. There were significant differences in plain CT value and fat proportion between DDLPS and well-differentiated liposarcoma (WDLPS) (P = 0.003, P = 0.022), and calcification was only observed in DDLPS. The positive rates of CDK4, P16, Vimentin and Ki-67 were all 100%, and the Ki-67 proliferation index of DDLPS was significantly higher than that of WDLPS (P < 0.001). The preoperative accurate CT diagnosis rate of LPS was only 9.3%, and the misdiagnosis rate of GIST reached 30.2%, mainly in DDLPS and fat-poor lesions. Traditional single CT sign could not independently explain the misdiagnosis risk. Conclusion: Abdominal and retroperitoneal LPS has strong heterogeneity and high preoperative misdiagnosis rate. The combination of plain CT value and fat proportion can non-invasively distinguish WDLPS from DDLPS. MDM2/CDK4/P16 triple immunohistochemistry combined with Ki-67 can accurately complete pathological diagnosis and malignant degree stratification. Traditional CT has inherent diagnostic limitations, and the combination of molecular pathology and radiomics can effectively improve preoperative diagnostic accuracy and guide clinical individualized treatment.