Skin cancer is the most common cancer diagnosed in the United States, representing the uncontrolled, abnormal growth of skin cells. Although sun exposure is a primary risk factor, these growths can appear anywhere on the body, making routine visual checks important. Early detection significantly improves treatment outcomes, especially for aggressive forms of the disease. Understanding the distinct visual signs of potential malignancy allows individuals to monitor their skin and know when to seek professional medical advice. This guide clarifies the visual markers to look for and explains the systematic process of conducting a thorough skin examination.
Visual Screening Standards
The ABCDE system is the most widely used method for visually screening suspicious moles and spots associated with melanoma. Each letter describes a characteristic that differs from a normal, harmless mole. These visual standards indicate that a spot requires professional evaluation, though they are not diagnostic by themselves.
Asymmetry means one half of the spot does not match the other half. A normal mole typically appears symmetrical. Border irregularity refers to edges that are blurred, ragged, or notched rather than smooth. Pigment may also appear to spread into the surrounding skin.
Color variation is present when the spot has multiple colors or uneven tones, such as shades of tan, brown, or black, or areas of white, red, blue, or pink. The Diameter rule suggests caution if a spot is larger than six millimeters (roughly the size of a pencil eraser). While melanomas can be smaller, this size is a general threshold for concern.
Evolving describes any change in a spot’s appearance over weeks or months. This includes changes in size, shape, color, or height, or new symptoms like bleeding, crusting, or itching. Any lesion that looks noticeably different from the other spots on the body—the “ugly duckling” sign—should also be monitored closely.
Distinct Visual Characteristics of Major Types
While melanoma often conforms to the ABCDE criteria, Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC) present with unique visual features.
Basal Cell Carcinoma (BCC)
BCC is the most common form and often develops on sun-exposed areas like the face and neck. Visually, BCC frequently appears as a shiny, waxy, pearly bump, sometimes with a translucent quality and rolled edges. It may also look like a flat, pinkish patch or an open sore that bleeds easily and does not heal.
Squamous Cell Carcinoma (SCC)
SCC, the second most common type, originates in the middle and outer layers of the skin. This cancer typically presents as a firm, red nodule or a rough, scaly patch that may crust over. These lesions often appear on sun-exposed skin but can also form as open sores that fail to heal completely. SCC has a higher potential for deeper invasion and spread than BCC, making early visual identification important.
Melanoma
Melanoma is the least common but most aggressive type, arising from pigment-producing cells (melanocytes). It can appear as a new, abnormal growth or a change in an existing mole, frequently displaying the ABCDE signs. While often dark brown or black, melanoma can sometimes be non-pigmented, appearing pink, red, or skin-colored. Monitoring for any new, unusual growth is important, as up to 70% of melanomas appear as entirely new spots.
Systematic Full-Body Self-Examination
Actively searching for suspicious spots requires a systematic approach to self-examination. Dermatologists recommend performing a head-to-toe check approximately once a month to establish a baseline of what is normal for your skin. Essential tools include a well-lit room, a full-length mirror, and a hand mirror to view hard-to-see areas.
The examination should proceed in an orderly fashion. Start with the face, ears, neck, and chest, then move to the arms, hands, and underarms. Check the palms, the backs of the hands, and under the fingernails, as cancer can develop in these locations. For the torso, women should inspect the skin underneath their breasts.
The most challenging areas require the use of the hand mirror or the assistance of a partner. These areas include the entire back, the back of the neck, the buttocks, and the genital area. Finally, inspect the lower body, including the front of the legs, the soles of the feet, and the spaces between the toes and under the toenails. Tracking notable lesions with photos or written notes can aid in monitoring changes over time.
Medical Consultation and Professional Diagnosis
If a spot matches any ABCDE criteria, or if a lesion is new, changing rapidly, or does not heal within a few weeks, consult a dermatologist. A professional evaluation ensures that any malignancy is caught early, even though most suspicious spots are harmless. Individuals with a personal or family history of skin cancer, or those with many moles, should seek annual professional skin exams.
During a professional skin check, the dermatologist performs a full-body visual exam. They often use a specialized handheld magnifying device called a dermatoscope. This device provides a closer, magnified view of the lesion’s structure beneath the skin’s surface, aiding in determining its nature. If the spot remains suspicious after this inspection, the physician will recommend a skin biopsy.
The biopsy involves removing a portion or the entirety of the abnormal growth for analysis by a pathologist. This is the definitive diagnostic procedure that confirms whether a growth is cancerous and determines its type. Early detection through this process is linked to the highest chance of successful treatment.