Inflammatory myofibroblastic tumor of the urinary bladder: report of six cases and review of the literature

Abstract

Objective To investigate the clinical features and treatment principles of inflammatory myofibroblastic tumor of the urinary bladder(IMTUB). Methods From April 2013 to October 2016, 6 cases of IMTUB patients were analyzed retrospectively. All cases were presented with gross hematuria. 4 cases underwent ultrasonography, of which 3 cases showed solid mass in bladder, 1 case showed inflammatory change. 6 cases underwent CT examination, 3 cases with bladder cancer, 1 case with bladder sarcoma, 1 case with malignant transformation of adenoma, 1 case with rich blood supply. No lymph node metastasis. Bladder occupying lesions were considered in 2 cases of MRI examination. 5 cases of cystoscopy showed bladder solid mass. In 6 cases involved, 2 patients received partial cystectomy, 2 patients underwent transurethral resection of bladder tumor, 1 patient underwent radical resection of urachal carcinoma and the other one was treated with chemotherapy. Results Immunohistochemical staining was positive in ALK (100.0%)、Vimentin(100.0%)、CK(100.0%)、SMA(83.3%)、EMA(66.7%) and Ki-67(5%-30%), negative in S-100 and Desmin. Final pathological diagnosis was IMTUB. So far, neither recurrence nor metastasis has been detected for 6~42 months in 5 cases and the other one lost to follow-up. Conclusions IMTUB is a kind of rare benign tumor of bladder. The golden standard of diagnosis is pathological diagnosis. Surgical resection is the first choice for treatment. Recurrence and metastasis are after the surgery treatment. All patients should be followed up closely. Key words: Bladder; Inflammatory myofibroblastic tumor; Diagnosis; Treatment