The specific anatomy of the glabrous skin, characterized by marked orthokeratosis and the presence of furrows and ridges, results in peculiar dermoscopic patterns of acral melanocytic lesions. Most frequently, acral nevi are typified by a parallel furrow pattern and acral melanoma (AM) by a parallel ridge pattern (PRP). Although the dermoscopic patterns of AM have been extensively investigated, little attention has been paid to site-related differences between palmar and plantar AM. The current study aimed to compare patients’ characteristics, melanoma thickness, and the morphologic variability of AM depending on the localization on palms or soles. Patients demographics and dermoscopic images of 118 AM, including 99 (83.9%) plantar and 19 (16.1%) palmar lesions (mean thickness, 2.1 mm), were extracted from the databases of seven pigmented skin lesion clinics and were evaluated for the presence of predefined criteria. Palmar melanomas were remarkably more frequent in women (male-to-female ratio, 1/3.8) and thinner than plantar melanomas (1.3 vs. 2.2 mm). Dermoscopically, no significant differences were found between plantar and palmar melanomas, with PRP scored in 64.6 and 68.4% of plantar and palmar lesions, respectively. Non-site-specific melanoma criteria were detected in 83.9% of lesions and, among melanomas not exhibiting a PRP, 95.1% showed at least one non-site-specific melanoma criterion. In conclusion, plantar and palmar AMs show sex-related and thickness-related differences, but do not differ with respect to their dermoscopic features. For cases lacking the PRP, non-site-specific melanoma criteria may be considered as helpful additional clues for the correct diagnosis.
aSkin Cancer Unit, Arcispedale Santa Maria Nuova IRCCS, Reggio Emilia, Italy
bSecond Department of Dermatology, ‘Attikon’ General University Hospital, University of Athens, Athens, Greece
cDepartment of Dermatology, Medical University, Graz
dDepartment of Dermatology, Division of General Dermatology, Medical University, Vienna, Austria
eDepartment of Dermatology, Tokyo Women’s Medical University Medical Center East
fKobayashi Clinic, Tokyo
gDepartment of Dermatology, Shinshu University School of Medicine, Matsumoto, Japan
hDepartment of Dermatology, Centre Hospitalier Lyon-Sud, Claude Bernard – Lyon 1 University, Pierre Bénite, France
* Dr Aimilios Lallas and Dr Dimitrios Sgouros contributed equally to the writing of this manuscript.
Correspondence to Aimilios Lallas, MD, Skin Cancer Unit, Arcispedale Santa Maria Nuova, Viale Risorgimento 80, 42100, Reggio Emilia, Italy Tel: +39 052 229 5611; fax: +39 069 762 5822; e-mail: firstname.lastname@example.org
Received September 29, 2013
Accepted October 23, 2013