Diagnostic Approach for Brownish Discolorations on the Lower Lip

Warning Signs and Diagnostic Considerations

The American Cancer Society recommends that oral melanoma must be excluded through biopsy, as it carries significant mortality risk if not diagnosed early, with key warning signs including asymmetry, irregular borders, heterogeneous color, diameter >5-7mm, and dynamics (evolution/recent change) 1, 2, 3, 4
The National Institute for Health and Care Excellence (NICE) guidelines suggest that a full excisional biopsy with 2mm margin of normal skin is the standard practice for suspected malignant melanocytic lesions, not partial biopsy, and a surgical knife rather than laser or electrocoagulation should be used to avoid tissue destruction that may interfere with diagnosis 2, 4, 7
The British Association of Dermatologists recommends a complete physical examination including the entire skin surface and all regional lymph nodes (preauricular and cervical) to distinguish between benign pigmented lesions and malignant melanoma 2
The American Academy of Dermatology suggests that progressive change in lesion size is a major sign requiring excision, and clinicians should not delay biopsy in elderly patients with new pigmented lesions, as melanoma incidence peaks at 65 years 1, 2

The European Society for Medical Oncology (ESMO) guidelines state that histopathologic examination is mandatory to distinguish between benign pigmented lesions (melanoacanthoma, melanotic macule) and malignant melanoma, and document the exact size, color heterogeneity, border characteristics, and any signs of ulceration, bleeding, or inflammation 3, 5