Limitations in dermoscopic assessment of pigmented auricular lesions: a single-center retrospective study

Introduction:
Dermoscopy is an important tool in skin cancer screening significantly facilitating early diagnosis.

Objective:
To identify dermoscopic features of pigmented lesions located on the external ear, which were initially considered suspicious based on established melanoma screening algorithms.

Material and methods:
Six clinically and dermoscopically challenging auricular lesions subsequently confirmed as benign in histopathological examination were retrospectively analyzed. All lesions were marked as suspicious according to at least one dermoscopic screening algorithm.

Results:
Four out of six lesions (4/6; 66.7%) were histopathologically classified as nevi (three compound nevi and one dermal nevus) and the remaining two as seborrheic keratosis and melanosis (each 1/6; 16.7%). Five out of six lesions (5/6; 83.3%) fulfilled dermoscopic criteria of melanoma according to 7-point checklist and ‘Chaos and clues’ algorithms. The Menzies method method indicated 4 out of 6 lesions as potentially malignant (4/6; 66.7%), whereas one-third of lesions met dermoscopic criteria of CASH algorithm and 3-point checklist (2/6; 33.3%). Asymmetric pigmented follicular openings (4/6; 66.7%), hyperpigmented follicular openings (3/6; 50%) and angulated lines/rhomboids (3/6; 50%) were the most frequently encountered dermoscopic features of facial-specific melanoma. Two out of six lesions did not demonstrate any facial specific dermoscopic clues (2/6; 33.3%).

Conclusions:
Pigmented lesions located on the external ear are dermoscopically heterogeneous and may demonstrate both facial and extra-facial dermoscopic features. 7-point checklist and ‘Chaos and clues’ algorithms were least specific in the dermoscopic evaluation of auricular lesions.