An intradermal nevus is a common, non-cancerous type of mole that originates in the skin. It forms from a proliferation of melanocytes, the cells responsible for producing pigment, which cluster deep within the dermis, the second layer of the skin. These moles are common, affecting many individuals, and are a normal skin variation.
Characteristics and Appearance
An intradermal nevus appears as an elevated, dome-shaped bump on the skin’s surface. They can be skin-colored, pink, or light brown. Some may contain small, dilated blood vessels or brown flecks.
They have a soft, rubbery texture and vary in size, typically 5 millimeters to 1 centimeter. They are commonly found on the face, neck, scalp, trunk, and extremities, but can develop anywhere on the body. Hair growth from an intradermal nevus is common, especially in older individuals. These moles remain stable in appearance over time, though they may become slightly larger or more elevated with age.
Formation and Nature
Intradermal nevi develop when melanocytes, the pigment-producing cells, migrate deeper into the dermis. This distinguishes them from other moles like junctional nevi, where melanocytes are at the epidermis-dermis border, or compound nevi, with cells in both layers. The deeper location of these melanocytes results in a flesh-colored or only slightly brown appearance, as less pigment is visible.
These moles are benign growths and rarely transform into malignant melanoma. They typically emerge later in life, from childhood through adulthood, rather than being present at birth. As people age, existing moles can also migrate deeper into the skin, evolving into an intradermal nevus. This downward migration of melanocytes, known as maturation with descent, indicates a benign melanocytic nevus.
When to Seek Medical Advice and Management
While intradermal nevi are generally harmless, it is important to monitor any skin lesion for changes. You should consult a dermatologist if a mole exhibits any of the “ABCDE” warning signs, commonly associated with melanoma:
Asymmetry (one half unlike the other)
Border irregularity (uneven or ragged edges)
Color variation (multiple colors or uneven pigmentation)
Diameter larger than 6 millimeters (about the size of a pencil eraser)
Evolving (any change in size, shape, color, or new symptoms like itching or bleeding)
If an intradermal nevus is benign and causes no discomfort, medical intervention is typically unnecessary; observation is the usual course. However, removal may be considered for cosmetic reasons or if the mole causes irritation, such as catching on clothing. Common removal methods include shave excision (shaving off the mole) or excisional biopsy (surgically cutting out the entire mole). Laser treatment is another option, particularly for cosmetic concerns.