Tumor embolism

This lung section is from a 73 year old female with an established diagnosis of adenocarcinoma of the gall bladder. Numerous pulmonary arterial branches were occluded with tumor emboli as seen here.  Pulmonary infarcts had resulted.

Pulmonary embolism can result from microscopic or larger fragments of detached tumor reaching the pulmonary circulation. It can be massive and rapidly fatal or might be unrecognized premortem. Usually, circulating tumor cells are destroyed by local defense mechanisms in the lung but sometimes clusters of cells remain viable in the lumen of the vessels and produce obstruction. Differentiating the patients with tumor microembolism from those cancer patients who have pulmonary thromboembolism or lung metastases can be difficult.

Contributed by Dr. Teresita Redondo, St. Barnabas Medical Center, Livingston, NJ.