摘要目的 探讨伴炎性肌纤维母细胞肿瘤(IMT)样特征的去分化脂肪肉瘤(DDLPS)的临床病理学特征、诊断及鉴别诊断.方法 收集2013—2018年间就诊于南京医科大学第一附属医院、南京中医药大学附属医院及广西壮族自治区钦州市第一人民医院的5例伴IMT样特征的DDLPS,采用EnVision法检测免疫组织化学表型,荧光原位杂交(FISH)法检测MDM2基因扩增情况.结果 5例均为男性,年龄53～65岁(平均61岁).临床表现主要为肿块占位症状,肿瘤位于肠系膜2例,肠壁、腹膜后、精索各1例.大体上肿瘤无完整包膜,直径约3～13 cm,平均6.7 cm,切面灰白灰黄质韧.组织学上,肿瘤的去分化区域类似于IMT形态,瘤细胞梭形、多边形或星芒状,席纹状、小片状或杂乱排列,间质有多少不等的炎性病变和胶原.IMT的组织学表现(黏液型、富细胞型及少细胞纤维化型)在伴IMT样特征的DDLPS均可出现,其中,以少细胞纤维化型形态最为多见.肿瘤周边均可寻找到高分化脂肪肉瘤的区域.有1例伴有高级别DDLPS成分.免疫表型上,4例强阳性表达MDM2及p16,2例表达平滑肌肌动蛋白,1例结蛋白及CD34局灶阳性.4例行间变性淋巴瘤激酶(ALK)?1基因检测者均阴性.5例行FISH检测,均见MDM2基因扩增.5例均获随访资料,随访时间3～66个月(平均23个月),2例复发,无疾病进展病例随访时间3～14个月.结论 伴IMT样特征的DDLPS形态学类似IMT,但生物学行为更具有侵袭性,需要与IMT、炎症型或硬化型脂肪肉瘤、侵袭性纤维瘤病、孤立性纤维性肿瘤、低度恶性肌纤维母细胞肉瘤、低级别纤维肉瘤等其他中间型或低度恶性肿瘤鉴别.

abstractsObjective To investigate the clinicopathological features, diagnosis and differential diagnosis of dedifferentiated liposarcoma (DDLPS) with inflammatory myofibroblastic tumor (IMT)?like features. Methods Five cases of DDLPS with IMT?like features were collected from the First Affiliated Hospital of Nanjing Medical University, the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine and the First People′s Hospital of Qinzhou between 2013 and 2018. EnVision method and fluorescence in situ hybridization (FISH) were used to detect the immunophenotype of the tumor cells and the profile of MDM2 gene amplification respectively. Results All five cases were male and the median age was 61 (range 53 to 65) years. The clinical symptoms were mainly related to the space?occupying lesions. The tumors were located in duodenal mesentery (two cases), intestinal wall (one case), retroperitoneum (one case), and spermatic cord (one case). Grossly, the tumors were not well encapsulated, ranging from 3 to 13 cm (median 6.7 cm) in diameter, with tan to gray and firm cut surface. Histologically, the dedifferentiated component closely resembled inflammatory myofibroblastic tumor (IMT), with spindle / polygonal /stellate?shaped cells arranged in storiform, sheet?like, or random pattern, with varying degrees of chronic inflammation and fibrosis. All three major patterns seen in IMT (myxoid, cellular and hypocellular fibrous) were observed, the hypocellular fibrous pattern was the most common. Well?differentiated liposarcomatous component was found in the peripheral areas of all the tumors. One case had high grade dedifferentiated component. Four cases were strongly positive for MDM2 and p16. Two cases were positive for SMA, and one case was focally positive for desmin and one for CD34. None of the cases stained for ALK?1. FISH demonstrated MDM2 gene amplification in all five cases. Clinical follow?ups were available in all five cases and the interval ranged from 3 to 66 months (median 23 months). Two patients developed recurrences and one patient had metastasis. The remaining two patients were alive with no evidence of tumor recurrence at 3 and 14 months after surgery respectively. Conclusions DDLPS with IMT?like features is a more aggressive neoplasm than its histological mimic (IMT), and should not be misdiagnosed as other intermediate or low?grade malignant tumors, such as IMT, sclerosing liposarcoma, inflammatory liposarcoma, aggressive fibromatosis, solitary fibrous tumors, low?grade myofibroblastic sarcoma, and low?grade fibrosarcoma.