膀胱炎症性肌纤维母细胞瘤4例临床病理分析

Inflammatory myofibroblastic tumor of the urinary bladder:A clinipathologic study of 4 cases

目的探讨膀胱炎症性肌纤维母细胞瘤的临床病理学特征，免疫表型和鉴别诊断。方法分析4例膀胱炎症性肌纤维母细胞瘤患者的临床资料，对存档蜡块进行组织学及免疫组织化学染色观察，并随访。结果男1例，34岁，女3例，17—45岁。临床均表现为血尿和肿块。眼观：瘤体界限清楚或多结节状。镜检：肿瘤由梭形肌纤维母细胞、纤维母细胞和炎症细胞构成。免疫表型：波形蛋白（Vim）、平滑肌肌动蛋白（SMA）、肌肉特异性肌动蛋白（MSA）、结蛋白（Des）、细胞角蛋白（CK）阳性数分别为4／4、4／4、4／4、1／4、1／4，肌红蛋白（Myo）、肌球蛋白（actin）、S-100蛋白、ALK1，均为阴性。随访。1例45岁女性患者术后18个月局部复发，其余病例未见复发和转移。结论膀胱炎症性肌纤维母细胞瘤临床主要表现为血尿和肿块。组织病理学表现为黏液型、梭形细胞密集型、纤维型三种亚型。瘤细胞不同程度表达Vim、SMA、MSA、Des和CK。诊断应和梭形细胞结节、平滑肌肿瘤、横纹肌肿瘤、低度恶性肌纤维母细胞肉瘤、肉瘤样癌相鉴别，生物学行为呈交界性。

Objective To investigate the pathological characteristic, immunophenotypic and differential diagnosis of inflammatory myofibroblastic tumor（ IMT） of the urinary bladder. Methods The pathologic features of the IMT cases were studied, pathogenic as well as immunohistochemical staining were perforemed and all cases were followed up. Results One of the patients was male, aged 34, and the other three were female, aged from 17 to 45. The main manifestation of all cases was quick growing mass and urinal bleeding. Grossly, the tumors were well-circumscribed nodular in appearance. Microscopically, the toumor was characterized by myofibroblasts,fibroblast and inflammatory cell. Immunopheotype：the tumor cells expression for Vim, SMA, MSA, Des, Ck were 4/4,4/4,4/4,1/4,1/4 respectively but negative for myo, actin, s-100 protein and ALK1. Follow-up： one female patient recurred locally after 18 months and other cases showed no sign of local recurrence and metastasis. Conclusion IMT of urinary bladder arises mostly in old patients. Histologically,the tumors were classified as the mucilaginous subtype, spindle-cellular subtype and fibriform subtype. The tumor cells express Vim, SMA, MSA, Des and Ck. The diagnosis of the tumor mainly depends on histopathology and immunohistochemistry. More attention should be paid to differentiating this tumor from postoperative spindle cell nodule, embryonal rhabdomyosarcoma, benign tumors of smooth muscle, leiomyosarcoma,low-grade myofibroblastic sarcoma and sarcomatoid carcinoma. The biological behaviour of IMT of urinary baldder is intermediate.