Dermoscopic Management Rules

01Rule one: look at all lesions, not only the clinically suspicious ones. Many early melanomas are clinically banal but dermoscopically obvious; if dermoscopy is reserved for naked-eye-suspicious lesions, the technique cannot uncover what naked-eye examination missed. With experience and a polarized handheld instrument the time penalty for full-body dermoscopy is roughly two extra minutes per visit, which is acceptable for the diagnostic yield.

02Rule two: undress high-risk patients. Total body skin examination is recommended for any patient with personal history of skin malignancy, family history of melanoma in first-degree relatives, age under 50 with more than 20 nevi on the arms (a validated partial nevus count), or age over 50 with chronic solar damage. Approximately 400 patients need to be examined to find one melanoma overall; in patients aged 60 or above the rate is roughly 1 in 200. Skipping the total-body exam in higher-risk groups risks missing thick melanomas on covered or rarely shown sites.

03Rule three: the ten-second rule for solitary lesions. If a clinician cannot reach a confident benign or malignant call within roughly ten seconds of dermoscopic inspection, the lesion sits in the diagnostic gray zone. For solitary lesions in this zone the threshold for biopsy should be low, especially when atypical network, prominent regression, or peripheral irregular streaks are visible. A short-term monitoring strategy is reasonable for some, but for solitary equivocal lesions early excision is generally safer than monitoring.

04Rule four: compare and monitor multiple moles. In patients with multiple atypical nevi, the ten-second rule would over-trigger excision. Apply the comparative approach (look for the lesion that does not match the patient's predominant phenotype) plus sequential digital dermoscopy imaging. Short-term monitoring at 3 months catches changes that signal incipient melanoma (about 11% probability of melanoma when changes occur). Long-term annual monitoring catches slow-growing melanomas that change only over 12 to 24 months.

05Rule five: never monitor doubtful nodular lesions. Nodular melanoma frequently lacks the classic pigmented-melanoma criteria because most pattern-analysis features describe junctional or epidermal pigment. The blue-black rule (presence of both blue and black colors) helps recognize pigmented nodular melanoma. Milky-red areas and polymorphous vascular patterns mark amelanotic and hypomelanotic nodular melanoma. The operational rule is to look for criteria of benign tumors first (cherry angioma, irritated seborrheic keratosis, dermal nevus, dermatofibroma); if no confident benign diagnosis can be reached, excise rather than monitor. Short-term monitoring of doubtful nodules is dangerous because nodular melanoma can grow rapidly.

06Rule six: combine clinical and dermoscopic criteria. A lesion with reassuring dermoscopy but a discordant clinical story (recently appearing, growing, solitary on a sun-exposed site in an older adult) deserves excision regardless of dermoscopic appearance. Benign lesions show harmony between clinical and dermoscopic findings. Discordance is the trigger to act. Conversely, an alarming dermoscopic feature in a long-standing stable lesion in a patient with similar lesions can sometimes be reassured if the comparative approach supports stability.

07Rule seven: combine clinical and histopathologic criteria. Histopathology is the reference standard but is not infallible. Spitzoid lesions, regressed melanocytic lesions, and nevus-associated melanoma all have known histopathologic pitfalls. When a lesion was clinically and dermoscopically equivocal, the pathologist must be told. A bland histology report on a dermoscopically alarming lesion should prompt a re-cut, second opinion, or re-excision rather than reassurance.

08Indications for excision summarized from the IDS key points: any pigmented lesion with documented change in a high-risk patient; any lesion showing significant dermoscopic change at follow-up; lesions with blue and/or white regression structures; any suspicious nodular lesion (never monitor); melanocytic lesions with asymmetric peripheral globules; amelanotic or partially pigmented lesions with milky-red globules or atypical vessels; atypical blue nevi; all Spitzoid lesions in adults; isolated atypical 'seborrheic keratoses' to exclude SK-like melanoma; acral melanocytic lesions in adults with non-typical patterns; dermatofibromas with atypical patterns; and any lesion of uncertain diagnosis after clinical and dermoscopic examination.

09Patient self-monitoring complements clinician surveillance. Monthly self-examination for new or changing lesions, photographic mole maps for high-risk patients, and explicit instructions about asymmetry, color change, and bleeding empower the patient to flag interval changes between scheduled visits. The patient can also report subjective concern; the unverbalized 'something different' from a long-term self-watcher is a recognized clue and should not be dismissed.