Moles and Cysts
Moles, also called melanocytic nevi, are collections of melanocytes in the epidermis and dermis which can create brown, pink, or skin-colored bumps on the skin. They may be located anywhere on the body, although they are more prevalent in sun-exposed areas.
Sunlight may cause an increased number of moles or cause premalignant changes due to ultraviolet A and ultraviolet B radiation. Moles may develop an atypical appearance to the patient or to the dermatologist over time.Biopsy or removal is important, since moles with dysplastic features and atypical cells may pose an increased risk of malignant melanoma. Malignant melanoma may also develop within an existing mole.
Cysts are firm bumps located in the skin or just below the skin. They are most often derived from the keratinocytes. The most common cyst is an epidermal inclusion cyst (previously called sebaceous cyst), which contains thick white debris and often connects to the surface of the skin. The contents may be foul-smelling, and infection can cause pain.
Cysts may enlarge over time, rupture, or cause discomfort or other symptoms. Another common cyst is the pilar cyst, derived from the epithelium of the hair follicle. These present as hard nodules, usually on the scalp, but can enlarge and become quite uncomfortable over time.