Purpose: To analyze and discuss the clinical manifestations, diagnosis and treatment of Inflammatory Myofibroblastic Tumor IMT (IMT) in pediatric patients. METHODS: Retrospective summary analysis of 5 cases of inflammatory myofibroblastoma admitted to our hospital from May 2006 to June 2011. RESULTS: Case 1, a 12-year-old male, was admitted with 4 hours of carnal hematuria and abdominal findings: intravesical mass; intravenous pyelogram and voiding cystourethrography: intravesical mass, no vesicoureteral reflux. The tumor was located in the right anterior wall of the bladder, with a diameter of 4.0 cm and a ruptured surface. The tumor was excised completely 1.0 cm from the edge of the tumor. Pathological diagnosis: inflammatory myofibroblastoma. Ultrasound of the bladder was repeated at 3 and 8 months after surgery: no tumor was seen. Case 2, a 2-year-old male, presented with intermittent dyspareunia for 10 months as the main clinical manifestation. Abdominal ultrasound, CT:, and intravenous pyelogram showed a mass in the bladder triangle with a diameter of about 5 CM and bilateral vesicoureteral reflux. An exploratory cystectomy was performed 9 days after admission. The tumor was located in the bladder triangle, about 5 CM in diameter, infiltrating the bladder wall, and was immobile. The tumor was located in the bladder triangle with a diameter of about 5 cm and infiltrated the bladder wall. Postoperative pathological diagnosis: inflammatory myofibroblastoma. The parents gave up further treatment. Case 3, a 5-year-old male, was admitted to the hospital 8 months after abdominal inflammatory myofibroblastoma resection at an outside hospital and 2 months after tumor recurrence. The tumor was located in the mesenteric space with extensive adhesions and local metastasis to the ileocecal wall. The tumor and the affected intestinal canal were completely excised 5.0 cm (2.0 CM from the tumor margin) and the intestinal canal was anastomosed. Case 4, a 3-year-old male with IMT in the neck, was diagnosed as synovial sarcoma by pathology in an outside hospital, and the local mass reappeared after surgery. Although the treatment was changed to chemotherapy, the local mass reappeared after 5 months and grew rapidly and lung metastasis occurred, so the parents abandoned the treatment. Pathology 5, female, 5 years old, was admitted with generalized edema, joint pain, and pestle-like fingers/toes for more than one month; chest X-ray: right lower lung mass-like dense shadow; knee X-ray: extensive and obvious periosteal reaction of the backbone. Chest enhancement CT: a round-like soft tissue mass was seen under the right chest wall, about 5.2X3.6X5.2CM, with less uniform density, CT value 16-48HU, no enhancement area was seen in the center of the lesion after enhancement, and significant enhancement was seen in the rest of the area, CT value 90HU, considering the possibility of isolated pleural fibroma. The tumor was located in the right lung, half of which was deep into the lung and half of which was protruding into the pleural cavity, irregularly round, about 7CM in diameter. Conclusion: IMT occurs in the urinary tract, abdominal cavity, lung and other tissues and organs, and the clinical manifestations vary according to the site and the complications caused, with no specific clinical symptoms and signs, relying on postoperative pathological diagnosis. Although the lesion is benign, there is a possibility of recurrence and metastasis; IMT secondary to pulmonary osteoarthropathy has not been reported in the literature, and the mechanism may be related to the location of the lesion in the lung. Surgical resection is usually performed, and adjuvant chemotherapy is indicated in recurrent cases; the prognosis is poor after the occurrence of metastasis.