This report describes the successful use of anticoagulant agent to treat pulmonary thrombosis in a 17 years old adolescent and reverse severe hemodynamic compromise. Diagnosis of PE and monitoring its treatment were successfully achieved by echocardiography and perfusion scintigraphy. Treatment with an anticoagulant agents was followed by complete resolution. Pulmonary perfusion scintigraphy performed subsequently revealed no evidence of pulmonary thrombosis. The purposes of this article are to expand on the limited experience the use of scintigraphy and echocardiography in the diagnosis and follow-up of pulmonary thromboembolism and to present the association between infection with Mycoplasma pneumoniae and thrombosis in pulmonary vessels in children. Exaggerated release of inflammatory cytokines is a prominent feature of infection process. Overproduction of tumor necrosis factor, which is known to induce endothelial cells to synthesis of tissue factor and plasminogen activator inhibitor, may have been responsible for the development of thrombosis. Although relative contribution of these various possibilities are difficult to estimate, multiple factors may have acted together in this patient to promote pulmonary thrombosis.

        Key words: thrombosis of pulmonary artery in children, childhood pulmonary embolism