Yang S M, Wu R C, Qi S S, You J F
Department of Pathology, School of Basic Medical Sciences, Third Hospital, Peking University Health Science Center, Beijing 100191, China.
Department of Pathology, the Second Affiliated Hospital of Shandong First Medical University, Tai'an 271000, China.
Zhonghua Bing Li Xue Za Zhi. 2022 Jan 8;51(1):17-22. doi: 10.3760/cma.j.cn112151-20210324-00229.
To investigate the clinicopathological features and differential diagnoses of paratesticular liposarcoma. The cases were collected from 2012-2020, from the archives of the Department of Pathology, Peking University Third Hospital, with diagnosis confirmed by histology, immunostaining and FISH tests. Totally 19 patients were enrolled (including 11 in-hospital patients and 8 consultant cases). The patients aged 37-84 years (mean 57 years). The preoperative clinical diagnoses were spermatic cord/inguinal masses (nine patients), scrotal masses (seven patients), and inguinal hernia (three patients). Six lesions recurred after local resection, including one case extending from pelvic liposarcoma. Histologically, there were 10 cases of well-differentiated liposarcoma (WDLPS) and nine cases of dedifferentiated liposarcoma (DDLPS). WDLPSs mostly showed the combined features of lipoma-like, inflammatory and sclerosing subtypes (six patients); the other four WDLPSs had pure lipoma-like subtype features. DDLPSs were low-grade (three patients) or high-grade (six patients), with the morphology resembling myxofibrosarcoma, inflammatory myofibroblastoma, spindle cell sarcoma, pleomorphic undifferentiated sarcoma and pleomorphic liposarcoma. Intense inflammatory cells infiltration was commonly observed in five WDLPSs and two DDLPSs. Ossification was observed in three tumors. Immunohistochemically, the tumors were positive for MDM2 (8/10) and CDK4 (10/10), which were expressed in lipo-differentiating cells, spindle cells in WDLPS, and in dediffferentiated components. S-100 was only expressed by lipocytes (10/10). CD34 expression was positive and diffuse in the stromal cells of WDLPSs and focal or diffuse in dedifferentiated areas (10/10). FISH tests with an MDM2 gene probe were positive (12/12). Paratesticular liposarcoma may be overlooked by both clinicians and pathologists. WDLPS and DDLPS predominate, showing various histologic divergences. The presence of amplification of the 12q14-q15 region (containing the MDM2 and CDK4 genes) is helpful for making the correct diagnosis.
探讨睾丸旁脂肪肉瘤的临床病理特征及鉴别诊断。病例收集于2012年至2020年北京大学第三医院病理科存档资料，经组织学、免疫组化及荧光原位杂交（FISH）检测确诊。共纳入19例患者（包括11例住院患者和8例会诊病例）。患者年龄37 - 84岁（平均57岁）。术前临床诊断为精索/腹股沟肿物（9例）、阴囊肿物（7例）和腹股沟疝（3例）。6例病变在局部切除后复发，其中1例由盆腔脂肪肉瘤蔓延而来。组织学上，高分化脂肪肉瘤（WDLPS）10例，去分化脂肪肉瘤（DDLPS）9例。WDLPS大多表现为脂肪瘤样、炎症性和硬化性亚型的联合特征（6例）；其他4例WDLPS具有单纯脂肪瘤样亚型特征。DDLPS为低级别（3例）或高级别（6例），形态学上类似黏液纤维肉瘤、炎症性肌成纤维细胞瘤、梭形细胞肉瘤、多形性未分化肉瘤和多形性脂肪肉瘤。5例WDLPS和2例DDLPS中常见大量炎症细胞浸润。3例肿瘤出现骨化。免疫组化结果显示，肿瘤MDM2（8/10）和CDK4（10/10）阳性，在脂肪分化细胞、WDLPS中的梭形细胞以及去分化成分中表达。S - 100仅由脂肪细胞表达（10/10）。CD34在WDLPS的间质细胞中呈阳性弥漫性表达，在去分化区域呈局灶性或弥漫性表达（10/10）。用MDM2基因探针进行FISH检测均为阳性（12/12）。睾丸旁脂肪肉瘤可能被临床医生和病理医生忽视。WDLPS和DDLPS为主，表现出多种组织学差异。12q14 - q15区域（包含MDM2和CDK4基因）扩增的存在有助于做出正确诊断。
