Pulmonary Inflammatory Myofibroblastic Tumor Mimicking Septic Pulmonary Embolism Following a Dental Infection.

Inflammatory myofibroblastic tumors are rare mesenchymal neoplasms that may mimic infections. A 67-year-old man developed a persistent fever after dental extraction. Chest computed tomography revealed multiple bilateral peripheral pulmonary nodules with feeding vessel signs, suggesting a septic pulmonary embolism. Despite intravenous antibiotics, his fever persisted, and blood cultures remained negative. A video-assisted thoracoscopic lung biopsy revealed spindle cell proliferation with inflammatory infiltrates. The patient's condition deteriorated rapidly, and he developed multi-organ failure and died on hospital day 27. A subsequent immunohistochemical analysis demonstrated ALK positivity, confirming the diagnosis of an inflammatory myofibroblastic tumor. An early tissue diagnosis is important when a presumed infection fails to respond to treatment.