摘要目的 探讨梭形细胞脂肪瘤(spindle cell lipoma,SCL)/多形性脂肪瘤(pleomorphic lipoma,PL)的临床病理学特点和鉴别诊断.方法 收集复旦大学附属肿瘤医院病理科2006年8月至2017年6月65例SCL/PL的临床和病理资料,行光镜观察和EnVision法免疫组织化学检测,采用荧光原位杂交(FISH)法检测MDM2基因扩增及DDIT3基因易位情况,并复习相关文献.结果 男性53例,女性12例,发病年龄26~82岁(平均年龄57岁,中位年龄59岁).肿瘤主要发生于颈部/颈后部/项部、上背部和肩部,少数病例位于四肢、面部和躯干、会厌、纵隔、大阴唇、会阴等部位.临床表现为皮下缓慢性生长的无痛性结节或肿块,直径1~13 cm(平均4.1 cm,中位3.5 cm).镜下观察:45例SCL中,28例(62.2%)为经典型,6例(13.3%)为黏液样型(树突状纤维黏液脂肪瘤),5例(11.1%)为乏脂肪型,3例(6.7%)为低脂肪型,3例(6.7%)为假血管瘤样型.20例PL中11例(55.0%)为经典型,6例(30.0%)为混合性SCL/PL,3例(15.0%)为乏脂肪型.免疫组织化学标记显示,梭形细胞脂肪瘤中的梭形细胞和多形性脂肪瘤的小花环状多核细胞强阳性表达CD34(52/52,100.0%),并可表达bcl?2(24/26,92.3%)和CD99(6/6),但不表达S?100蛋白和STAT6.FISH检测无MDM2基因扩增(0/17),也无DDIT3基因相关易位(0/4).所有病例均经手术切除,随访32例(3~96个月),仅1例局部复发.结论 SCL和PL属于同一瘤谱,镜下形态可有较大差异,尤其是低脂肪型和乏脂肪型易被误诊,需注意与其他具有相似形态和免疫表型的肿瘤相鉴别.

abstractsObjective To investigate the clinical and pathological features of spindle cell lipoma (SCL)and pleomorphic lipoma(PL)with emphasis on differential diagnosis.Methods Sixty?five cases of SCL/PL from the archive of Department of Pathology, Fudan University Shanghai Cancer Center, from August of 2006 to June of 2017, were included in the study. Immunohistochemistry by EnVision method, MDM2 gene amplifycation and DDIT3 gene translocation by fluorescence in situ hybridization(FISH)were detected and the literature was reviewed.Results There were 53 males and 12 females with age ranging from 26 to 82 years(mean,57 years;median,59 years). The majority of the lesions occurred in the neck/posterior neck/nuchal region, upper back and shoulder. A small percentage of lesions developed in the extremities, face and trunk, and rarely in the epiglottis, mediastinum, labium majus and perineum. Clinically,the tumor usually manifested as a slowly growing mass or nodule. It was often encapsulated, ranging from 1 to 13 cm(mean,4.1 cm;median,3.5 cm)in size. Microscopically,SCL was composed of mature adipose tissue, bland spindle cells and bright eosinophilic"ropey"collagen fibers that varied in proportion. Of 45 SCL, 28 cases(62.2%)were classical, 6 cases(13.3%)were myxoid, 5 cases (11.1%)were fat?poor,3 cases(6.7%)were fat?free,and 3 cases(6.5%)were pseudoangiomatoid. PL showed similar features as SCL, but was characterized by the presence of scattered floret giant cells. Of 20 PL,11 cases(55.0%)were classical,6 cases(30.0%)were mixed SCL/PL,3 cases(15.0%)were fat?free. Both SCL and PL contained scattered mast cells in the stroma. By immunohistochemistry, the spindle cells in SCL and the floret giant cells in PL showed strong positivity for CD34(52/52,100.0%), bcl?2(24/26,92.3%)and CD99(6/6),whereas they were negative for S?100 protein and STAT6. FISH analysis of MDM2(17 cases)and DDIT3(4 cases)was negative in all cases. Follow?up information was available in 32 patients(3 to 96 months),with local recurrence in only one patient. Conclusions SCL and PL belong to the same entity but may exhibit morphological disparities. Of note, the fat?poor and fat?free variants are easily mistaken for other mesenchymal tumors. Attention should be paid in their differential diagnosis.