Inflammatory myofibroblastic tumor in pediatric patients: a Bosnian cohort

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm of intermediate biological potential, characterized by spindle cell proliferation and significant inflammatory component. This study aimed to determine the clinicopathologic characteristics, the clinical outcomes of inflammatory myofibroblastic tumor cases in the low-volume pediatric surgery service in a developing country.

The study included data from all IMTcases diagnosed and operated from 2010 to 2024  at the Clinic of Pediatric Surgery, Clinical Center University of Sarajevo.

Three pediatric patients (two females, one male) diagnosed with IMT were analyzed for demographic, clinical, histopathological, immunohistochemical, and outcome parameters. All tumors were located in the abdominal or abdominopelvic region, with a median patient age of 4 years. Clinical manifestations included non-specific gastrointestinal symptoms (n=2) and systemic signs such as fever (n=2), weight loss and weakness (n=1). Complete surgical resection was conducted in all patients, and all experienced complete remission without recurrence. Histopathological analysis revealed consistent presence of spindle cells within a prominent inflammatory milieu, rich in plasma cells and lymphocytes. Immunohistochemically, all tumors were positive for vimentin, ALK, and SMA, while ALK-FISH analysis (performed in one case) was negative. No significant nuclear atypia or mitotic activity was observed.

Our study showed the constant of its heterogeneous morphology, and significance of IMTs immunophenotype, particularly in older children, where the inflammatory component is more pronounced. ALK gene alterations are commonly associated with IMT, as well as with other types of pediatric neoplasms, however, favorable outcomes in our cohort study, raise question regarding further need to clarify the prognostic significance of molecular findings and their potential therapeutic implications.