Inflammatory Myofibroblastic Tumor Presenting as a Sigmoid Colon Mesenteric Mass in a Child: Diagnostic and Therapeutic Insight.

We present the case of a 1-year-old girl who had been experiencing gastrointestinal symptoms for 15 days. The clinical examination showed a 3 cm × 3 cm mass in the lower abdomen that was not tender and did not move. The contrast-enhanced computed tomography imaging revealed a 4.7 cm × 5.5 cm soft tissue density lesion in the left half of the pelvis, which is likely to have originated from the ovary. The surgical exploration uncovered a 5 cm × 6 cm × 5 cm solid-cystic mass originating from the sigmoid colon mesentery. The histopathology report indicated a benign mesenchymal tumor, favoring inflammatory myofibroblastic tumor (IMT)-WHO intermediate grade. After the surgery, there was no recurrence, and the patient's recovery was smooth. This case highlights the challenges in diagnosing IMT due to its nonspecific symptoms and the crucial role that immunohistochemistry and histopathology play in accurately identifying the condition. The foundation of treatment remains surgical removal, with ongoing monitoring recommended due to the potential for recurrence.