Melanocytic Melanoma Mimics

Melanocytic melanoma mimics

Blue Nevi

Blue nevi are benign melanocytic nevi with nevus cells located deep within the dermis. Their blue to black coloration may suggest melanoma. Blue nevi are sharply defined, uniform in color, and are stable in size or appearance over many years.

Combined Nevus

Combined nevus refers to the combination of a blue nevus deep in the dermis associated with an overlying benign junctional, compound or intradermal nevus. Combined nevi are usually solitary and are often asymmetric with focal dark pigmentation. This presentation suggests melanoma though the patient has not noted any change in the lesions appearance.

Traumatized Nevi

Traumatized nevi may be partially avulsed and/or have hemorrhagic crusting suggesting ulceration. Patients are usually aware of the trauma. Nevi previously partially removed either by trauma or biopsy can develop recurrent nevus phenomenon over several weeks to months. Melanocyte hyperplasia develops superficial to the scar resulting in uneven pigmentation and irregular outlines as pigment extends into the surrounding skin-quite suggestive of melanoma. Recurrent nevus phenomenon can resemble melanoma histologically, as well. The history of trauma or biopsy along with review of the original biopsy helps exclude a diagnosis of melanoma.