Histopathological study of pulmonary arteries in 14 autopsy cases with massive pulmonary thromboembolism.

As the pathological features of acute massive pulmonary thromboembolism (PTE) remain unclear, early diagnosis is difficult. We examined 14 autopsy cases of sudden death by massive PTE. Eight cases were male and six female, with a mean age of 57+/-18 years. While none of the cases were diagnosed with PTE during their lifetime, 12 cases had predicting factors for thrombosis. Deep vein thrombosis was found at autopsy in 11 cases. Cross sections of each segmental pulmonary artery were dissected for histological examination. The distribution of fresh thrombi and organized thrombi in the pulmonary arteries was investigated. Results revealed that 13 cases contained both fresh and organized thrombi. More detailed examination indicated that as the organized thrombi were spread in all lobes, the distribution of thrombi extended from the proximal to peripheral arteries. Our findings indicated that most cases of fatal PTE had a subclinical recurrent history. Thus, proper diagnosis and treatment of prior emboli may be vital for the prophylaxis of sudden death by PTE.