Photo Credit: Jodi Jacobson

The following is a summary of “Perifollicular linear projections: A dermatoscopic criterion for the diagnosis of lentigo maligna on the face,” published in the JANUARY 2024 issue of Dermatology by Navarrete-Dechent, et al.

Lentigo maligna (LM) poses diagnostic challenges due to its resemblance to benign pigmented lesions. For a study, researchers sought to introduce a novel dermatoscopic feature termed “perifollicular linear projections (PLP)” as a diagnostic criterion for LM on the face.

A retrospective analysis utilized reflectance confocal microscopy and dermatoscopy images from two databases, focusing on flat facial pigmented lesions. PLP was defined as short, linear, pigmented projections emerging from hair follicles. Dermatoscopy readers, unaware of histopathologic outcomes, assessed the images.

Among 83 consecutive LMs, 25.3% displayed “bulging of hair follicles” on reflectance confocal microscopy, and 85.7% of these cases exhibited PLP on dermatoscopy. In a database of 2873 consecutively imaged and biopsied lesions, PLP was observed in 61.8% of 76 melanomas and 3.9% of 176 lesions with other diagnoses (P < .001). The diagnostic sensitivity and specificity of PLP were 61.8% (95% CI, 49.9%-72.7%) and 96.0% (95% CI, 92.9%-98.4%), respectively. Multivariate analysis demonstrated an independent association between PLP and LM diagnosis (OR 26.1 [95% CI, 9.6%-71.0]).

The newly described dermatoscopic criterion, PLP, may enhance sensitivity and specificity in early diagnosing LM on the face. PLP is proposed as an intermediary step in the progression model of LM.

Source: jaad.org/article/S0190-9622(23)02503-3/fulltext