growth: non-pigmented tumors were bigger than pigmented and it was much easier for them to spread. They shown that there are both pigmented and non-pigmented cells in melanoma tumors, so that they can both be drug-resistant and metastatic. Diagnosis Looking at the area in question is the most common method of suspecting a melanoma. Moles that are irregular in color or shape are typically treated as candidates. To detect melanomas (and increase survival rates), it is recommended to learn to recognize them (see "ABCDE" mnemonic), to regularly examine moles for changes (shape, size, color, itching or bleeding) and to consult a qualified physician when a candidate appears. However, many melanomas present as lesions smaller than 6 mm in diameter, and all melanomas are malignant when they first appear as a small dot. Physicians typically examine all moles, including those less than 6 mm in diameter. Seborrheic keratosis may meet some or all of the ABCD criteria, and can lead to false alarms. Doctors can generally distinguish seborrheic keratosis from melanoma upon examination or with dermatoscopy. Some advocate replacing "enlarging" with "evolving": moles that change and evolve are a concern. Alternatively, some practitioners prefer "elevation". Elevation can help identify a melanoma, but lack of elevation does not mean that the lesion is not a melanoma. Most melanomas in the US are detected before they become elevated. By the time elevation is visible, they may have progressed to the more dangerous invasive stage. In-person inspection of suspicious skin lesions is more accurate than visual inspection of images of suspicious skin lesions. When used by trained specialists, dermoscopy is more helpful to identify malignant lesions than use of the naked eye alone. Reflectance confocal microscopy may have better sensitivity and specificity than dermoscopy in diagnosing cutaneous melanoma but more studies are needed to confirm this result. Ugly duckling One method is the "ugly duckling sign". Correlation of common lesion characteristics is made. Lesions that deviate from the common characteristics are labeled an "ugly duckling", and a further professional exam is required. The "Little Red Riding Hood" sign suggests that individuals with fair skin and light-colored hair might have difficult-to-diagnose amelanotic melanomas. Extra care is required when examining such individuals, as they might have multiple melanomas and severely dysplastic nevi. A dermatoscope must be used to detect "ugly ducklings", as many melanomas in these individuals resemble nonmelanomas or are considered to be "wolves in