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The Seven Point Check List
The seven point checklist is more detailed and has better specificity in differentiating benign melanocytic lesions from melanoma. There are major and minor criteria. The major criteria score two points and the minor criteria one. A minimum score of three is required for the diagnosis of melanoma. A score of less than three suggests it is not a melanoma.
The major criteria are
1. An atypical pigment network. This is defined as a black, brown or grey network with irregular holes and thick lines. It scores 2 points.
2. A blue white veil. This is defined as a structureless area of confluent blue pigmentation with an overlying white ground glass appearance. Pigmentation cannot occupy the entire lesion and neither does the veil. This scores 2 points if present.
3. The third major criteria is an atypical vascular pattern. This is defined as linear, irregular or dotted vessels not clearly seen within regression structures. It scores 2 points.
4. The minor criteria are irregular streaks. These are defined as brown or black peripherally located projections from the edge of the lesion, which may be seen to arise from the network. They score 1 point.
5. The next minor criteria are irregular dots and globules defined as black or brown round or oval structures distributed irregularly within the lesion. They score 1 point.
6. The next minor criteria is
irregular blotches. These are defined as black brown or grey structureless areas. Again asymmetrically distributed and scoring I point
7. And the seventh minor criteria are regression structures. These are white scar like depigmented areas and areas of gray pepper like granules. They again score 1 point.
A score of three or more allows melanoma to be diagnosed with a sensitivity of 95% but a specificity of only 75%. It is difficult to apply the seven point checklist or any other algorithm for that matter to lesions on the face and on the palms and soles. In these locations there are specific diagnostic dermatoscopic features that point to a diagnosis of melanoma including incomplete perifollicular pigmentation and rhomboidal structures in lentigo maligna and the parallel ridge pattern in acral melanoma.
Question: How would you score this lesion?