Acral Lentiginous Melanoma Diagnosis and Management

Introduction to Acral Lentiginous Melanoma

The American Academy of Dermatology and other guideline societies recommend that any persistent pigmented lesion on acral sites warrants immediate evaluation, regardless of race, due to the aggressive nature of acral lentiginous melanoma (ALM) 4
The British Association of Dermatologists suggests that a 30-year-old individual with a 5-month persistent lesion on the sole of their foot requires urgent referral to a dermatologist or surgeon with expertise in pigmented lesions, to be seen within 2 weeks, as ALM must be excluded 1, 2, 3

The National Comprehensive Cancer Network recommends evaluating for specific ALM characteristics, including asymmetry, border irregularities, color heterogeneity, and evolution in size/appearance (ABCD criteria) 5, 6, 3
The American Joint Committee on Cancer suggests that size and thickness of the lesion, as well as presence of ulceration, are critical factors in determining prognosis and treatment 5, 6
Complete skin examination, including all acral sites, regional lymph nodes, and assessment for satellites or in-transit metastases, is essential for accurate diagnosis and staging 5, 6, 1, 3
Dermoscopy by an experienced physician significantly enhances diagnostic accuracy for pigmented lesions 5, 6, 7

The British Association of Dermatologists recommends that full-thickness excisional biopsy is mandatory and is the only acceptable diagnostic approach for ALM, including the entire lesion with a 2-5 mm clinical margin of normal skin and a cuff of subdermal fat 1, 2, 3
The American Academy of Dermatology suggests that shave and punch biopsies are absolutely contraindicated as they make pathological staging impossible and lead to sampling error 1, 2, 3
Incisional biopsy is occasionally acceptable for acral melanoma when performed by specialists within a skin cancer multidisciplinary team, but only when complete excision is impractical 5, 6, 1

The National Comprehensive Cancer Network recommends that for invasive melanoma, margins depend on Breslow thickness: <1 mm depth requires a 1 cm margin, 1-2 mm depth requires a 1-2 cm margin, and >2 mm depth requires a 2 cm margin 8, 5, 6, 2
The American Joint Committee on Cancer suggests that wide local excision with lymph node dissection should be considered for lesions with severe regression or measuring >1 mm 8, 5, 6, 2

The National Comprehensive Cancer Network recommends that SLNB should be discussed for lesions ≥0.8-1.0 mm thickness or thinner lesions with adverse features (ulceration, high mitotic rate) 8, 5, 6
The American Society of Clinical Oncology suggests that patients with lymph node metastases at diagnosis have significantly shorter survival 8, 5, 6