Sudden and unexpected death due to undiagnosed pulmonary thromboembolism in an adolescent male without previous history of trauma.

We report a case of sudden death in a 19-year-old adolescent male who had been receiving hospital treatment because of a persistent right calf pain which had started about 18 days previously. The pain had not been relieved by analgesics, and had extended to the right thigh. The post-mortem examination revealed that the cause of death was pulmonary embolism by thrombi which had arisen in the right calf veins. The bilateral pulmonary arteries were packed with thrombi, and many pulmonary branches were occluded with fresh thrombi. The right calf veins contained thrombi of differing ages. In old thrombi, massive collagen formation and hemosiderin granules were present but elastic fibers had not yet formed. Therefore, it was considered that the old thrombi had formed at the time of the patient's first visit to the hospital. The right calf pain for which the deceased had sought medical advice was considered to have been caused by the vein thrombosis. Although various risk factors for the formation of thrombi are known, in the present case no precedent causes other than obesity were identified.