[A case of pulmonary tumor thrombotic microangiopathy caused by carcinoma (salivary duct carcinoma) ex pleomorphic adenoma].

A 53-year-old man with carcinoma (salivary duct carcinoma) ex pleomorphic adenoma was admitted to our hospital because of dyspnea. He received chemotherapy in July 2007, and was subsequently followed up without chemotherapy. A chest CT scan revealed multiple faint ground glass attenuation bilaterally. Contrast-enhanced CT did not reveal any emboli in the large pulmonary arteries. An echocardiogram showed severe pulmonary hypertension. Tc-99m-MAA lung perfusion images showed multiple small defects in both lungs. The serum level of vascular endothelial growth factor (VEGF) was normal. He died of heart failure 23 days after admission. An autopsy was performed, and microscopic examination revealed tumor cell embolism, intimal fibrocellular proliferation of the small arteries, fibrin thrombi and recanalization. A diagnosis of pulmonary tumor thrombotic microangiopathy (PTTM) was made. Immunohistochemical staining of the tumor cells for VEGF was weakly positive. To the best of our knowledge this is the first reported case of PTTM caused by a salivary gland tumor.