Multi-Organ Involvement of an Immunoglobulin G4-Related Inflammatory Pseudotumor of the Urogenital Tract: A Case Report

An inflammatory pseudotumor (IPT) is a rare tumor composed of proliferative myofibroblasts, fibroblasts, histiocytes, plasma cells, and lymphocytes (1). IPT is mainly seen in young patients and often involves the lung and orbit, but it may occur in virtually any anatomic location and in patients of any age. Although IPT usually presents as an isolated mass in a single organ, it sometimes manifests in the form of multifocal lesions that are concentrated in one anatomic region (2). Few IPT cases have been reported in the ureter and bladder. The lesions are usually benign, but some abdominal cases have exhibited malignant potential or metastasis. Recently, some experts have suggested classifying IPT into three categories, including plasma cell-rich IPT [also known as lymphoplasmacytic or immunoglobulin G4 (IgG4)-related IPT] (3). In this case report, we describe the clinical, imaging, and pathology lab results of an IgG4-related IPT that occurred in a patient’s periureteral area, paravesical space, and prostate.