Transillumination Health Dictionary

A procedure that is sometimes carried out during physical examination of a lump or swelling.

Light from a small torch is shone on 1 side of the lump; if it can be seen on the other side, the lump contains clear fluid.

n. the technique of shining a bright light through part of the body to examine its structure. Transillumination of the sinuses of the skull is a means of detecting abnormalities.