In some cancers, the presenting factor is an effusion, or fluid, in the pleural, pericardial, or peritoneal spaces. research has found that almost 50% of undiagnosed effusions in people not known to have cancer turn out to be malignant. which cancers are often found because of effusions?

Lung and ovarian cancers.

Explanation:

Cancer may be defined as the uncontrolled division of the cell and require less nutrient media for its growth. The property of apoptosis has been lost in the cancer cell.

Effusion may be defined as the instance or presenting the liquid, pericardial fluid or smell. Some cancers are marked by the property of effusion. Lung cancer and ovarian cancer shows effusion. The fluid are filled that are yellow or pinkish in color with slightly smell.

Thus, the answer is lung and ovarian cancers.

all the above is what i would say