Si H P, Wang Z, Fan Q H, Zhang Y F, Yang D Q, Zhang Z H, Gong Q X
Department of Pathology, the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine, Nanjing 210029, China.
Department of Pathology, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Zhonghua Bing Li Xue Za Zhi. 2019 Apr 8;48(4):282-287. doi: 10.3760/cma.j.issn.0529-5807.2019.04.004.
To investigate the clinicopathological features, diagnosis and differential diagnosis of dedifferentiated liposarcoma (DDLPS) with inflammatory myofibroblastic tumor (IMT)-like features. 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. 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. 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.
探讨具有炎性肌纤维母细胞瘤（IMT）样特征的去分化脂肪肉瘤（DDLPS）的临床病理特征、诊断及鉴别诊断。2013年至2018年期间，从南京医科大学第一附属医院、南京中医药大学附属医院和钦州市第一人民医院收集了5例具有IMT样特征的DDLPS。采用EnVision法和荧光原位杂交（FISH）分别检测肿瘤细胞的免疫表型和MDM2基因扩增情况。5例均为男性，中位年龄61岁（范围53至65岁）。临床症状主要与占位性病变有关。肿瘤位于十二指肠系膜（2例）、肠壁（1例）、腹膜后（1例）和精索（1例）。大体上，肿瘤包膜不完整，直径3至13 cm（中位直径6.7 cm），切面呈黄褐色至灰白色，质地硬。组织学上，去分化成分与炎性肌纤维母细胞瘤（IMT）极为相似，梭形/多边形/星状细胞呈束状、片状或随机排列，伴有不同程度的慢性炎症和纤维化。观察到IMT中常见的三种主要类型（黏液样、细胞性和少细胞纤维性），少细胞纤维性类型最为常见。所有肿瘤周边均可见高分化脂肪肉瘤成分。1例有高级别去分化成分。4例MDM2和p16强阳性。2例SMA阳性，1例结蛋白局灶阳性，1例CD34阳性。所有病例ALK-1均无染色。FISH显示5例均有MDM2基因扩增。5例均有临床随访，随访时间为3至66个月（中位23个月）。2例复发，1例转移。其余2例分别在术后3个月和14个月存活，无肿瘤复发迹象。具有IMT样特征的DDLPS比其组织学类似物（IMT）更具侵袭性，不应误诊为其他中低级别恶性肿瘤，如IMT、硬化性脂肪肉瘤、炎性脂肪肉瘤、侵袭性纤维瘤病、孤立性纤维性肿瘤、低级别肌纤维母细胞肉瘤和低级别纤维肉瘤。
