Aggressive inflammatory pseudotumor of the abdomen 9 years after therapy for Wilms tumor. A complication, coincidence, or association?

Abstract

Inflammatory pseudotumor (IPT) is a benign lesion that occurs in various organs and tissues. It is usually sharply demarcated from the surrounding tissue and surgery is considered to be the best treatment. This article discusses a 15-year-old boy with an aggressive IPT of the abdomen occurring 9 years after therapy for Wilms tumor. IPT widely involved the esophagus, stomach, and liver, producing severe dysphagia. Histologically, it showed classic features of IPT and, also, areas of metaplastic bone, a new feature recently described in the same lesion of the kidney. It mimicked malignant tumor clinically and led to extensive surgery, but early follow-up has shown no recurrence. Although many complications of surgery and chemotherapy are well known, the authors believe that it is unlikely to be the cause of IPT in the case presented. Therefore, the possibility of coincidence or association of Wilms tumor and IPT remains open.