婴幼儿炎症性肌纤维母细胞肿瘤5例临床病理分析

Inflammatory myofibroblastic tumor of infant: a clinicopathologic study of 5 cases

目的观察婴幼儿炎症性肌纤维母细胞肿瘤（IMT）的临床病理特征、免疫表型,探讨婴幼儿IMT的诊断、鉴别诊断、治疗及预后。方法收集5例婴幼儿IMT,分析其临床病理特征、免疫表型并随访。结果患儿5例,男1例,女4例,年龄8~22个月,中位年龄14个月。发生于肺部2例,腹腔3例。镜下表现为胖梭形纤维母细胞/肌纤维母细胞增生,呈束状或旋涡状排列,间质内伴有数量不等的炎细胞浸润,主要为成熟的浆细胞、淋巴细胞和嗜酸性粒细胞。肿瘤细胞排列疏松或致密,2例均可见体积较大的神经节样细胞。免疫组化：3例ALK胞质（＋）,2例（-）。随访3例ALK阳性病例中2例复发,1例失访。2例ALK阴性病例无复发。结论 IMT是一种少见的中间型肿瘤,好发于儿童,婴幼儿期罕见,需与其它梭形细胞肿瘤鉴别,该瘤具有复发潜能,偶可转移,术后需密切随访观察。

Objective To investigate the clinicopathologic features,diagnosis,differential diagnosis,treatment and prognosis of infantile inflammatory myofibroblastic tumor（ IMT）. Methods Five cases of infantile IMT with follow-up data were clinicopathologically reviewed. Results There were one male and four females. The age was 8 to 22 months,and the median age was 14 months. The tumor involved in the lung（ 2 cases） and in the abdominal cavity（ 3 cases）.Histologically,infantile IMT was a lesion composed of fascicles of bland myofibroblastic cells with an inflammatory infiltrate consisting of lymphocytes,plasma cells,and eosinophils. There were ganglion-like cells in 2 cases. Anaplastic lymphoma kinase（ ALK） expression was positive in 3 cases,2 of which recurred. Two cases were negative for ALK with no recurrence. Conclusion IMT is a rare neoplastic lesion with a high incidence in children,but extremely rare in infant and it must be distinguished from other spindle cell tumors. Careful long-time follow-up after operation is required because of the risk of recurrence and the limited therapeutic options other than surgery.