Signs and Symptoms
Basal Cell Carcinoma
There are five major subtypes of basal cell carcinoma, each with a different appearance. Most basal cell carcinomas (85%) occur on the head and neck, with at least a third in areas that receive little or no sun exposure (Firnhaber 2012).
Nodular. Nodular basal cell carcinomas have a variable appearance, but commonly present as a pearly pink or white, dome-shaped raised lesion with prominent surface reddening due to dilated blood vessels.
Superficial. Superficial basal cell carcinomas are scaly plaques that resemble eczema or psoriasis, with characteristic raised, pearly white borders. Superficial basal cell carcinoma is the least invasive of the subtypes and most commonly occurs on the trunk and extremities.
Micronodular and infiltrative. These are more malignant subtypes of basal cell carcinoma that are difficult to distinguish visually from the nodular subtype.
Morpheaform. Morpheaform basal cell carcinoma lacks the pearly appearance of the nodular subtype, appearing as a firm, yellowish, ill-defined mass.
Squamous Cell Carcinoma
Squamous cell carcinoma commonly appears as a firm, smooth or scaly raised lesion, often ulcerated; patients commonly describe it as bleeding after minimal trauma. Squamous cell carcinomas are often localized to the backs of the hands and forearms as well as areas of the head and neck that receive maximal sun exposure (Firnhaber 2012; Ferri 2014).
Melanoma usually appears as an irregularly pigmented skin lesion that changes over time. They most commonly occur spontaneously, but occasionally arise from a pre-existing nevus (birthmark or mole). The ABCDE rule is a useful guide to identifying signs of possible melanoma. The characteristics of a melanoma are (ACS 2013b):
- Asymmetrical shape;
- Borders that are irregular, ragged, or blurred;
- Color that is not the same all over and may include shades of black, brown, pink, red, white, or blue;
- Diameter of more than 6 mm (the size of a pencil eraser);
- Evolving or changing in shape, size, or color.
It is important to remember that these characteristics are a guideline, and not every melanoma follows these rules (Dunki-Jacobs 2013). Other signs associated with melanoma are a sore that does not heal; spread of pigment from a spot to the surrounding skin; redness or swelling outside the border of a mole; and itchiness, pain, or changes in the surface of a mole (ACS 2013b).