Abstract
Inflammatory myofibroblastic tumor (IMT) is a rare type of tumor composed mainly of fibroblastic and myofibroblastic spindle cells, with an inflammatory infiltrate of lymphocytes, plasma cells, and eosinophils. IMT may arise from different organs and sites, but it is infrequent to arise from the urinary bladder and usually manifests as hematuria. We report a case of a 24-year-old pregnant woman who presented to our hospital with gross hematuria. After further workup, we concluded that she had this extremely rare tumor, which was resected eventually with a partial cystectomy. Although the diagnosis of these kinds of tumors is usually made by anaplastic lymphoma kinase (ALK) using immunohistochemistry and detecting ALK gene translocation using fluorescence in situ hybridization (FISH), they were negative in our study; hence, we relied mainly on the morphological features of the tumor for the diagnosis.