Multiple intraosseous inflammatory myofibroblastic tumors presenting with an aggressive clinical course: Case report

Background and Importance: The authors report a rare case of multiple intraosseous inflammatory myofibroblastic tumors presenting with an aggressive clinical course. Clinical Presentation: A 60-year-old man presented with a 3-month history of headache and 2 weeks of jaw pain. Magnetic resonance imaging showed a homogeneously enhancing mass in the right parietal bone with subcutaneous and intracranial invasion. Bone scintigraphy revealed 4 intraosseous lesions involving the cranium, mandible, ischium, and calcaneum. After admission, the patient showed left hemiparesis and seizures caused by rapid intracranial tumor extension. The cranial and mandible tumors were resected. Histopathological examinations of both specimens revealed myofibroblastic spindle cell proliferation with inflammatory cell infiltration, and a diagnosis of inflammatory myofibroblastic tumor was made. Two days postoperatively, the patient presented with a high fever and disturbance of consciousness with swelling of the subcutaneous tissues of the head and mandibular lesions. Magnetic resonance imaging revealed a massive intracranial extension of the tumor. Corticosteroid therapy induced remarkable shrinkage of all lesions, and relief from symptoms was obtained. Radiotherapy was then performed for residual tumors. Conclusion: Multiple intraosseous inflammatory myofibroblastic tumors of the bone are very uncommon and may mimic malignant tumors. It is important to recognize that this entity can occur in the cranium and as multiple bony lesions. The recommended treatment is complete surgical resection with adjuvant steroid treatment. Considering the aggressive nature of this entity, additional chemo- and/or radiotherapy may be warranted.