A multicentric study on dermoscopic patterns and clinical–dermoscopic–histological correlates of basal cell carcinoma in Indian skin

Abstract

Background Literature on the dermoscopic patterns of basal cell carcinoma (BCC) in India is limited. Aim To describe the dermoscopic pattern and dermoscopic–histopathological correlation in a large cohort of patients with BCC from India, with a particular focus on skin of colour (SOC). Methods This retrospective study was conducted under the aegis of the Dermatoscopy Society of India. Clinical details were collected, and two lead authors independently analysed dermoscopic images of BCC for a predefined set of characteristics. Histopathological slides/blocks were reviewed, and dermoscopic–histological correlation attempted. Results In total, 143 patients with BCC and skin phototypes IV–VI were included. The mean largest BCC diameter was 3.10 ± 3.68 cm and there was a significant but weak association between duration and largest dimension of the lesion (Spearman ρ = 0.33, P < 0.01). Nearly half of the cases were diagnosed with pigmented BCC and the most common histological subtype was nodular BCC (37.9%). Dermoscopically, blue–grey dots and arborizing vessels were the most common features (60.0%). Pigmentary changes were found in the majority of cases, and included blue–white veil, blue–grey ovoid nests and maple leaf‐like areas. A third of our patients had short linear telangiectasia, polymorphic vessels and regular dotted vessels, and another third exhibited a dermoscopic rainbow effect. Arborizing vessels were significantly more common with micronodular (78.9%) and nodular variants (74.1%, P = 0.05), whereas regular dotted vessels (68.4%, P = 0.04), blue–white veil (84.2%, P = 0.02) were significantly associated with micronodular variant. Conclusion The dermoscopic patterns of blue–white veil and regular dotted vessels are indicators towards micronodular BCC in SOC and can help in prioritizing treatment.

Dermoscopic Clues of Histopathologically Aggressive Basal Cell Carcinoma Subtypes

“…Other frequent dermoscopic features were milky red structureless areas, arborizing vessels, short fine telangiectasias and ulceration. A previous study reported similar findings with an even higher frequency of blue pigmentation, but it was conducted in a population with darker skin color [ 20 ]. Indeed, BCCs developing in individuals with dark phototypes (IV–VI, according to the Fitzpatrick classification) display pigment more frequently, regardless of the histological subtype, as compared with BCCs in patients with fair skin [ 20 ].…”

“…A previous study reported similar findings with an even higher frequency of blue pigmentation, but it was conducted in a population with darker skin color [ 20 ]. Indeed, BCCs developing in individuals with dark phototypes (IV–VI, according to the Fitzpatrick classification) display pigment more frequently, regardless of the histological subtype, as compared with BCCs in patients with fair skin [ 20 ]. In a study by Vinay et al on 19 micronodular BCCs in Indian patients, the prevailing structure was blue pigmentation, especially blue-white veil, being as high as in 84.2% of cases, followed by nests and dots (78.9% versus 68.4%) [ 20 ].…”

“…In detail, in the systematic review conducted by Reiter et al on the dermoscopic clues of BCC and its subtypes, 53 samples of morpheaform tumors were included and analyzed [ 16 ]. Overall, morpheaform BCCs were mainly non-pigmented, with one study reporting white porcelain areas as the prevailing dermoscopic feature (present in 75% of the sample) [ 15 , 20 ]. Interestingly, although rare, when present, pigmentation was commonly in the form of large blue-grey ovoid nests (13%, 95% CI 0−36%) [ 16 ].…”

“…Indeed, BCCs developing in individuals with dark phototypes (IV–VI, according to the Fitzpatrick classification) display pigment more frequently, regardless of the histological subtype, as compared with BCCs in patients with fair skin [ 20 ]. In a study by Vinay et al on 19 micronodular BCCs in Indian patients, the prevailing structure was blue pigmentation, especially blue-white veil, being as high as in 84.2% of cases, followed by nests and dots (78.9% versus 68.4%) [ 20 ]. The highest frequency, as compared with our study, is probably explained by the different populations.…”

“…However, the results of both studies converge to the conclusion that micronodular BCC often displays blue pigmentation, unlike the other three histopathologically aggressive subtypes. The latter finding is also clinically relevant because it has been demonstrated that pigment allows a better delineation of the tumor margins, facilitating surgical treatment [ 20 ].…”