Pediatric inflammatory myofibroblastic tumor with late metastasis to the lung: case report and review of the literature.

Inflammatory myofibroblastic tumors (IMTs) are challenging lesions with respect to classification, differential diagnosis, and biologic potential. In children, extrapulmonary IMTs, particularly those from the abdomen or mesentery, are generally aggressive, with frequent local recurrences. There are few documented patients with distant metastasis, and most of these had metastases at presentation or developed metastases within months to a few years. We add to the short list of metastatic extrapulmonary IMTs a pediatric patient in whom the primary lesion was widespread in the abdomen at presentation and metastatic disease to the lung was diagnosed 9 years after the primary resection. We describe the clinical and pathologic features of this patient and review the characteristics of extrapulmonary IMTs with distant metastasis reported in the literature.