To explore the diagnostic characteristics of intraperitoneal inflammatory myofibroblastic tumor (IMT) in children.

A retrospective analysis was performed on the clinical data of 2 pediatric patients with intraperitoneal IMT who were admitted to the Department of Pediatric Surgery at Shandong Provincial Hospital Affiliated to Shandong First Medical University in October 2021 and September 2023, respectively. The clinical diagnostic characteristics were summarized using information from the literature.

Both patients were females, aged 4 years, 10 months, and 12 years, respectively. The primary complaints were intermittent upper stomach pain and fever. Laboratory studies revealed varied degrees of hemoglobin decrease in both patients, although tumor markers were not markedly abnormal. The levels of C-reactive protein and procalcitonin were increased in the younger patient. In the younger individual, abdominal ultrasound revealed a hypoechoic mass in the left adrenal area, while the elder patient showed a hypoechoic mass at the splenic hilum. Abdominal CT plain and enhanced scans revealed an intra-abdominal tumor between the spleen and stomach in the younger individual, a rich blood supply, uneven enhancement on the enhanced scan, a tight relationship to the spleen, and malignancy could not be excluded.In the elderly patient, a hypoechoic mass near the splenic hilum was discovered, supplied by the splenic artery, and an enhanced scan revealed uneven enhancement, indicating malignancy. Both patients showed no invasion of adjacent tissues, abdominal fluid buildup, or swollen lymph nodes. Both patients underwent chest CT, radionuclide bone scan, and bone marrow puncture, which revealed no evidence of lung or bone metastases. Due to the high size of the tumor, the younger patient required open surgery to completely resect the abdominal lesion, whereas the elder patient underwent laparoscopic surgery. Both procedures resulted in total tumor removal, and the postoperative pathology diagnosis confirmed IMT. Postoperative follow-up for 25-month and 3-month respectively revealed no recurrence or metastases.

IMT in the pediatric abdomen lacks distinct clinical signs and auxiliary testing procedures, making preoperative diagnosis problematic. Comprehensive surgical resection is required for treatment, and a postoperative pathology evaluation can confirm the diagnosis.