Inflammatory pseudotumor following hematopoietic stem cell transplantation: a new case and review of the literature.

Inflammatory pseudotumor (IPT) is a rare tumor that occurs in various organs and tissues. The clinical picture varies from the more frequent benign lesions to the rare malignant tumors with distant metastases. IPT associated with hematopoietic stem cell transplantation (HSCT) is rarely reported. In this article, we review the reports of IPT after HSCT and describe the first case of bladder IPT. We also review the possible factors involved in the pathogenesis. IPT might be rare but it is a potentially serious complication of HSCT. It should be considered in patients with otherwise unexplained inflammatory symptoms or signs or with any mass lesion in the post-HSCT period. A knowledge of this entity and insistence on a definitive biopsy of mass lesions in the post-HSCT period can avoid unnecessary treatment such as radical surgery, chemotherapy or radiotherapy.