junction nevus [L, jungere, to join, naevus, birthmark] , a hairless flat or slightly raised brown skin blemish arising from pigment cells at the epidermal-dermal junction. A junctional nevus may be found anywhere on the surface of the body. Malignant change may be signaled by increase in size, hardness or darkening, bleeding, or appearance of satellite discoloration around the nevus. Junctional nevi undergoing these changes and lesions found in areas subject to trauma should be evaluated by a dermatologist.
