Subacute pulmonary hypertension due to pulmonary tumor microembolism as a clinical manifestation of occult gallbladder adenocarcinoma.

We report a 67-year-old man who developed pulmonary hypertension as an initial clinical manifestation of occult gallbladder adenocarcinoma. He had a 6-week history of persistent dry cough followed by progressive dyspnea on exertion. Physical examination and chest roentgenogram revealed signs of precapillary pulmonary hypertension. He died of shock 1 h after pulmonary angiography, which failed to show any intravascular filling defects. Autopsy disclosed a mucin-producing small adenocarcinoma (2 cm diameter) and a gallstone in the gallbladder with a few small metastases to peri-aortic, peri-bronchial and mediastinal lymph nodes. Macroscopically, there was no gross thrombotic pulmonary embolism or pulmonary metastases. However, microscopically, more than 60% of the small pulmonary arteries less than 1 mm in diameter were occluded with pulmonary tumor microemboli. This case emphasizes the need to include tumor pulmonary embolism in the differential diagnosis of pulmonary hypertension whether or not there is evidence of an underlying malignant tumor.