Pulmonary hypertension attributable to neoplastic emboli: An autopsy study of 20 cases and a review of literature.

Twenty cases of pulmonary hypertension attributable to neoplastic emboli were the subject of this retrospective autopsy study (1951-1990) at the Mayo Clinic. Fourteen patients were women, and ages ranged from 18 to 82 years (mean 49). In three patients, tumor was clinically occult, and in only one case was the diagnosis of neoplastic pulmonary hypertension considered clinically. The mean interval between diagnosis of malignancy and development of respiratory symptoms was 14 months, but the mean interval between respiratory symptoms and death was only one month. At autopsy, the three most common primary sites for neoplasm were breast (40%), stomach (15%), and lung (10%). All 20 cases revealed subacute changes of pulmonary hypertension, either with medial hypertrophy of muscular pulmonary arteries (70%) or with right ventricular hypertrophy (45%) or dilatation (40%). However, three subgroups were identified based on microscopic and gross features: (i) 6 patients with predominantly neoplastic microemboli, (ii) 10 patients with mixed neoplastic and thrombotic microemboli, and (iii) 4 cases with both neoplastic microemboli and large, fatal tumor emboli (primary tumors in kidney, femur, cervix, and thyroid). In conclusion, neoplastic pulmonary hypertension is most commonly associated with carcinoma of the breast, accounting for the observed female preponderance. It is generally associated with a rapid clinical course once respiratory symptoms develop, and large, fatal, acute neoplastic emboli account for a substantial number of deaths (20% in the present series).