Giant Nevus - Bathing Trunk Nevus

A bathing trunk nevus is a large, pigmented, molelike birthmark. It covers an extremely large area of the body, often in the area covered by a pair of bathing trunks. It is often covered with hair.

What is going on in the body?

A collection of mole, or nevus, cells forms a very large brown mole during fetal development. The bathing trunk nevus is present at birth.

What are the causes and risks of the condition?

Although the cause of bathing trunk nevus is unknown, there may be a hereditary factor in some cases.