Yes, this warrants prompt dermatologic evaluation
Any new or changing pigmented lesion developing over months to a year, particularly in a genital location, should be evaluated by a dermatologist or specialist experienced in pigmented lesions to rule out melanoma. While genital nevi can be benign "nevi of special sites," the slow progressive development you describe raises concern and requires expert assessment.
Why This Requires Evaluation
The genital area is a recognized "special site" where melanocytic nevi can display atypical features that mimic melanoma 1. However, several factors make your patient's presentation concerning:
Progressive change over time: The most critical warning sign is the dynamics or evolution of these lesions over one year 2, 3. Change in size, shape, or color is a major criterion in the ABCD rule for melanoma detection and should never be ignored.
Melanoma can occur in genital locations: While rare, melanoma of the penis carries a particularly poor prognosis, often due to delayed presentation because patients are reluctant to seek care for lesions in this location 4.
"Ugly duckling" concept: If these lesions look different from the patient's other nevi, this increases suspicion 2, 3.
Key Clinical Features to Assess
When evaluating these lesions, look for the seven-point checklist features 5:
Major signs (most important):
- Change in size
- Change in shape
- Change in color
Minor signs:
- Diameter ≥7 mm
- Inflammation (reddish tinge)
- Sensory change (itch, increased awareness)
- Crusting, oozing, or bleeding
Melanomas typically have three or more of these features 5. The presence of any major sign warrants referral.
Management Algorithm
Urgent referral to dermatology: Patients with suspicious pigmented lesions should be seen within 2 weeks 6. The genital location and progressive nature make this urgent.
Full skin examination: The specialist should perform a complete skin examination to identify other suspicious lesions and assess the patient's overall nevus pattern 6, 3.
Dermoscopy: An experienced clinician using dermoscopy significantly improves diagnostic accuracy 2, 3.
Excisional biopsy if indicated: If melanoma cannot be excluded clinically, full-thickness excisional biopsy with 2-5 mm margins is the gold standard 6, 2, 3. Shave or punch biopsies are contraindicated as they prevent accurate Breslow thickness measurement 6.
Important Caveats
Nevi of special sites (including genital nevi) can show histologic atypia that mimics dysplastic nevi or even melanoma, but they are not risk markers and are not malignancies 1. However, this is a pathologic diagnosis that requires tissue examination—it cannot be assumed clinically.
Low but real risk: While studies show that genital nevi have limited malignant potential (one study found 1.46% recurrence rate and no melanoma progression in genital nevi) 7, the progressive nature of your patient's lesions distinguishes them from stable nevi.
Early melanoma has excellent prognosis: If melanoma is caught when <1 mm thick, 5-year survival is approximately 90% 5. This makes early evaluation critical.
Patient reluctance: Patients often delay seeking care for genital lesions due to embarrassment 4. Proactive encouragement to seek evaluation is essential.
Bottom line: The combination of genital location, progressive development over one year, and the serious consequences of missing an early melanoma makes specialist evaluation mandatory. When melanoma is a consideration, sensitivity is more important than specificity—some over-referral is acceptable to avoid missing a curable malignancy 5.