Anaplastic lymphoma kinase inhibitor therapy in the treatment of inflammatory myofibroblastic tumors in pediatric patients: Case reports and literature review

Background: : Inflammatory myofibroblastic tumors (IMTs) are a rare subtype of inflammatory pseudotumor frequently associated with rearrangement of the anaplastic lymphoma kinase (ALK) gene. Their treatment has historically relied on at-times challenging and morbid surgical excision. Recent studies have shown that neo/adjuvant therapy with ALK inhibitors can significantly enhance outcomes in select patients. Methods: : A systematic literature review was performed to characterize comprehensive treatment of ALK-positive IMTs in the pediatric population. This report also includes two patients from our home institutions not previously reported in the literature. Results: : We identified a total of 27 patients in 12 studies in addition to 2 patients from the senior authors’ institution for a total of 29 patients (median age, 7 years; 52% male). The IMTs comprised a wide range of anatomic locations. Almost half (12, 41.3%) were treated with ALK-inhibitors alone and felt to be in remission. The remainder was treated with ALK-inhibitors either before or after surgery and had a curative response. Conclusions: : ALK-positive IMTs can be successfully treated with ALK-inhibition alone or in combination with surgical resection. Further genetic characterization may be helpful in determining more precise treatment and defining needed durations thereof.