Acral Amelanotic Melanoma Mimicking a Foot Ulcer

Abstract

Acral amelanotic melanoma can be difficult to diagnose and is often clinically aggressive. The present report describes a case of an acral amelanotic melanoma presenting as a non-healing wound after mimicking a plantar wart for two years. The decision to biopsy a borderline-suspicious lesion on the lower extremity in an elderly individual must be weighed carefully, as lower extremity biopsy carries a risk of poor wound healing and other complications. We discuss clinical and epidemiologic features that can assist in deciding when to perform a biopsy in this setting and can improve the early detection of acral amelanotic melanoma.

Misdiagnosis and Clinical Insights into Acral Amelanotic Melanoma—A Systematic Review

“…Dermoscopically, an AAM has several features that distinguish it from pigmented melanoma. AAMs may present with irregular vascular patterns, including polymorphous vessels and areas of milky red erythema, which may facilitate dermoscopic identification [5,32,33]. Histologically, AAM is characterised by atypical melanocytes lacking melanin [32].…”

“…In contrast, the presentation of ALM, often characterised by brown or black shades in a striated or diffuse pattern, is more likely to raise suspicion of melanoma [8,38,39]. Dermoscopy is very helpful in differentiating AAM from ALM; while the diagnosis of AAM may be based on subtle vascular patterns and the absence of pigmented structures, ALM may present with more definitive indicators of melanoma, such as pigment networks [5,8]. Another important aspect is the differentiation of AAM from other malignancies such as sarcomas, which may confuse the physician due to their tendency to involve similar acral sites [40,41].…”

“…It suggests that healthcare professionals should approach acral lesions of the lower limbs with a higher index of suspicion and more readily consider histological evaluation. Since AAM can be masked by benign lesions, especially in the early stages, a more meticulous and timely approach may lead to earlier diagnosis and intervention, which are critical in the management of this potentially life-threatening condition [5].…”

“…The aggressive nature of AAMs means that a delayed diagnosis can lead to missed opportunities for early intervention, significantly impacting patient outcomes. Adding to the diagnostic challenge is the anatomical location of acral melanomas, which frequently overlaps with various benign lesions like warts, calluses, and cysts [5][6][7]. These similarities can obscure a correct diagnosis and increase the risk of misidentifying the malignancy.…”

“…These similarities can obscure a correct diagnosis and increase the risk of misidentifying the malignancy. Recognizing the importance of early detection and an accurate diagnosis, an emerging body of literature has documented cases of AAMs initially misdiagnosed as other lesions [5,8]. Despite the presence of case reports and small case series, a comprehensive and systematic review is required to synthesise the existing evidence and shed light on this diagnostic dilemma.…”