Pseudosarcomatous myofibroblastic tumour of the urinary bladder: a case report.

A pseudosarcomatous myofibroblastic proliferation is an unusual and a rare benign lesion which arises from the bladder submucosal stroma and is easily mistaken for a malignant neoplasm, clinically, radiologically and histologically. By definition, the tumour is composed of a dominant spindle cell proliferation with a variable inflammatory component. These spindle cells are now known to be myofibroblasts and this is the reason for the current designation for this disease. The term 'inflammatory' may not be applicable to all the tumours, since some investigators have demonstrated the presence of chromosomal abnormalities and have documented cases which showed recurrence, thus supporting the theory that at least some of these tumours were true neoplasms.Non-epithelial tumours account for 2-5% of all the primary urinary bladder neoplasms, with the most common types being rhabdomyosarcoma in patients under the age of 10 years and leiomyosarcoma in adults. A pseudosarcomatous myofibroblastic tumour is a nonepithelial lesion that follows a benign indolent course and a conservative management has been reported as the treatment of choice. Herein, we are reporting a case of a pseudosarcomatous myofibroblastic tumour which was mistaken for a sarcoma clinically and radiologically and which was proved as a pseudosarcomatous inflammatory myofibroblastic tumour by histopathology and immunohistochemistry.