黏液型血管瘤样纤维组织细胞瘤的临床病理学观察

Myxoid variant of angiomatoid fibrous histiocytoma： a clinicopathologic analysis of 3 cases

目的探讨黏液型血管瘤样纤维组织细胞瘤（AFH）的临床病理学特征、诊断及鉴别诊断。方法收集2008-2017年就诊于南京医科大学第一附属医院的3例黏液型AFH患者资料，采用EnVision法检测免疫组织化学表型，采用荧光原位杂交（FISH）法检测EWSRl基因断裂重排情况。结果3例中男性2例，女性1例，年龄分别为13、31和42岁。临床表现主要为偶然发现或缓慢生长的无痛性肿块。肿瘤位于浅表软组织（皮下、黏膜下）2例，深部软组织（腹膜后）1例。大体上肿瘤最大径分别为1、7和2cm，切面灰白质实。组织学上，肿瘤均境界清楚，有纤维性包膜及淋巴细胞鞘。肿瘤呈模糊的多结节状分布，问质广泛黏液变性（≥60％）。黏液丰富区域瘤细胞相对稀疏，呈梭形或星芒状，条索状或丝网状排列，或杂乱无章的分布于间质中；瘤细胞相对丰富区域可见经典AFH的组织／树突样细胞合体样生长，排列呈小片状、短束状、交错状或局部旋涡状。瘤细胞轻．中度异型性，核分裂象可见（≤2／10HPF）。未见肿瘤性坏死。仅1例见裂隙状出血性腔隙。另有1例部分间质出现丰富的硬化性胶原。3例均表达CD68、CDl63，2例表达结蛋白、上皮细胞膜抗原和CD99，1例表达Calponin和平滑肌肌动蛋白。S-100蛋白、CD34、CD31、CD35、CD21、广谱细胞角蛋白均阴性。FISH检测示EWSRl均阳性。2例获随访结果，分别随访6个月和89个月，未见复发或转移。结论黏液型AFH的临床表现、免疫表型、分子遗传学改变及生物学行为与经典型AFH相同．但组织形态学特殊，需要与肌上皮瘤、神经源性肿瘤等富含间质黏液的肿瘤鉴别。

Objective To study clinicopathologic features, diagnosis and differential diagnosis of myxoid variant of angiomatoid fibrous histiocytoma （ AFH ） . Methods Three cases of myxoid variant of AFHs were collected from First Affiliated Hospital of Nanjing Medical University during 2008 and 2017. EnVision method and fluorescence in situ hybridization （FISH） were used to detect immunophenotype and EWSR1 gene rearrangement, respectively. Results There were 2 males and 1 female with age at 13, 31, and 42 years, respectively. The patients presented with a painless mass located superficially （ subcutaneous or submucosal） in two cases or deep-seated （retroperitoneum） in one case. Grossly, the diameters of tumors were 1,7, and 2 cm, respectively. The cut surface was solid and firm, tan to gray in colour. Histologically, the circumscribed tumor had fibrous pseudocapsule and peritumoal lymphoplasmacytic infiltrates. The tumor cells arranged in vaguely nodular growth pattern, with prominent myxoid stroma （present in 60% to 100% of the entire tumor）. In hypocellular myxoid areas, the spindle to stellate tumor cells arranged in cords or reticular pattern, or in a haphazard manner. However, histiocytoid cells arranged in faseicular, sheet-like, or whorled growth pattern, as in classical AFH, were also identified in hypercelluar areas. Mild to moderate atypia was observed with low mitotic rate of （0-2）/10 HPF. Tumor necrosis was not seen. One case presented with slit-like hemorrhage and sclerosing collagen intermingled with myxoid matrix was identified in 1 case. Immunohistochemically,all cases were positive for CD68 and CD163. Two of three were positive for desmin, EMA, CD99 and one for Calponin, SMA. All cases were negative for S-100 protein, CD34, CD31, CD35, CD21 and CKpan. FISH detection was positive for EWSR1 gene in all cases. Available clinical follow-up was obtained in 2 cases, revealing no evidence of disease in 6 and 89 months, respectively. Conclusions Myxoid variant of AFH is a histological subtype of AFH, with clinical features, immunophenotypes, genomie profiles and biological behavior similar to typical AFH. Their unusual morphology is easily confused with a variety of other myxoid mesenehymal neoplasms, including myoepithelioma and nerve sheath tumors.