Moles, medically termed nevi, are common skin growths resulting from the proliferation of pigment-producing cells. Almost everyone has nevi, which vary widely in appearance, size, and location. Understanding the specific type of mole you have can help address any concerns about its nature. This guide focuses on one frequent type: the intradermal nevus.
Defining the Intradermal Nevus
The term “intradermal” describes the location of the nevus cells within the skin layers. An intradermal nevus is characterized by melanocytes—the pigment-producing cells—located exclusively within the dermis, the layer beneath the epidermis. These cells have fully migrated away from the junction between the two layers.
This nevus represents the final, mature stage in a mole’s lifecycle. Moles often begin as flatter junctional nevi before progressing to compound nevi (cells in both layers), and finally becoming the intradermal nevus (cells only in the lower layer). This progression occurs over many years, with the intradermal form typically appearing in late childhood or adolescence.
How to Identify an Intradermal Nevus
The visual characteristics of an intradermal nevus are distinct from other mole types. These nevi are typically raised, presenting as a dome-shaped or papular bump on the skin surface. They may have a soft, rubbery texture or appear slightly warty or pedunculated (attached by a stalk).
Due to the deep location of the melanocytes, the nevus cells are covered by the epidermis, resulting in a lighter appearance. Intradermal nevi are frequently flesh-colored, light tan, or slightly pink, unlike the dark colors associated with shallower moles. They are usually small (5 millimeters to 1 centimeter in diameter) and have well-defined, symmetric borders. Hairs often grow directly from the surface of these mature moles.
Why Intradermal Nevi are Generally Harmless
The primary reason intradermal nevi are considered benign relates to the deep, stable location of their cells. Once melanocytes have migrated entirely into the dermis, they are mature and stable, making malignant transformation rare. These non-cancerous growths typically remain unchanged for decades, often losing pigmentation as a person ages.
Standard mole monitoring guidelines still apply, such as noting any changes in the lesion’s appearance. The ABCDE rule helps identify suspicious changes: Asymmetry, irregular Border, varied Color, large Diameter, and Evolving appearance. Intradermal nevi usually do not exhibit these features, maintaining a uniform color and size over time.
Any mole that begins to change rapidly, bleed, itch, or show new, irregular pigmentation should be evaluated by a dermatologist. While uncommon, an intradermal nevus is not immune to malignant alteration, emphasizing the importance of professional assessment for any new signs.
When and How Removal is Considered
Removal of an intradermal nevus is usually considered for elective reasons rather than medical necessity. The primary motivation is cosmetic concern, especially when the mole is large or located prominently on the face or neck. Removal may also be medically indicated if the nevus is frequently irritated by clothing, shaving, or friction, leading to chronic discomfort.
If removal is necessary, the method depends on the nevus’s size and depth. For typical raised lesions, a shave excision is the common technique. The mole is numbed with a local anesthetic and shaved flush with the surrounding skin.
For deeper or larger lesions, or if clinical suspicion requires a full tissue sample, a surgical excision is performed. This method removes the entire lesion and a small margin of surrounding tissue, requiring sutures. Surgical excision ensures complete removal and is preferred when diagnostic certainty is required.