Skin Cancer Warning Signs: The ABCDE Rule for Melanoma and Beyond

Early detection saves lives. Use the ABCDE rule to monitor moles for melanoma:

Letter	Feature	Description
A	Asymmetry	Halves don't match
B	Border	Irregular, scalloped, poorly defined
C	Color	Varied shades (brown, black, red, white, blue)
D	Diameter	>6 mm (pencil eraser), but can be smaller
E	Evolving	Change in size, shape, color, elevation, or symptoms

Non-Melanoma Skin Cancer Signs

• Basal cell carcinoma (BCC): Pearly papule, telangiectasia, ulceration, rolled borders.
• Squamous cell carcinoma (SCC): Scaly crusted nodule, non-healing sore, cutaneous horn.
• Merkel cell carcinoma: Rapidly growing painless nodule on sun-exposed skin.

Other Warning Signs

• Nail: Longitudinal melanonychia (new or widening dark streak).
• Scalp: Non-healing lesion hidden by hair.
• "Ugly duckling" sign: A lesion that looks distinctly different from all others on your body.

Action Plan

• Monthly self-skin examination.
• Annual full-body dermatologist exam (every 6–12 months for high-risk individuals).
• Biopsy any suspicious lesion—histopathology is the only definitive diagnosis.

Melanoma 5-year survival: 99% (localized) vs. 30% (distant). Early detection is curable.