Inflammatory myofibroblastic tumors of the urinary tract: a clinical diagnosis and treatment review in pediatric

Abstract

Objective To improve the diagnosis and treatment of inflammatory myofibroblastic tumor (IMT) of the urinary tract in pediatric. Methods The retrospective study of 12 IMT was based on information retrieved from Beijing Children′s Hospital from January 2006 to July 2015. The literatures of urinary IMT were reviewed. There were 12 cases of urinary IMT, with 8 cases in bladder, 2 in kidney, 1 in ureter and 1 in prostate. Mean age at surgery was 6.4 years old (range 2months-13 years), 6 cases males and 6 females. Tumor resection were performed in 11 patients, biopsy was performed only in 1 patient. Results HE staining revealed diffuse appearing spindle myofibroblastic cells admixed with inflammatory cells. Immunohistochemistry showed positive ration for following markers as ALK (8/12), CK18 (6/12), Desmin (7/12), SMA (8/12), Actin (1/2), Vimentin (9/12). Negative staining were seen for Myoglobin, S-100 and Ki-67 < 20%.Patients were followed up in 10 cases, lost to follow-up in 2; the mean follow-up time was 14.4 months (range 3-31 months). All patients recovered well without relapse or metastasis. Conclusions Inflammatory myofibroblastic tumors of the urinary tract in pediatric were rare, without specific characteristic in clinical features and imaging. The main treatment of IMT is complete surgical excision. Key words: Inflammatory myofibroblastic tumor; Urinary System; Anaplastic lymphoma kinase(ALK)