Minimizing the dermatoscopic morphologic overlap between basal and squamous cell carcinoma: a retrospective analysis of initially misclassified tumours

Abstract

Background Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) have well‐established dermatoscopic criteria that make them relatively easy to recognize on a clinical basis. However, even with the addition of dermatoscopy, a morphologic overlap between the two tumours does exist. Objectives To analyse the dermatoscopic morphology of clinically and dermatoscopically misclassified BCCs and SCCs, to identify factors causing the erroneous clinical interpretation and, therefore, minimize the morphologic overlap between BCC and SCC. Methods Retrospective study including histopathologically diagnosed BCCs or SCCs that had been clinically inversely diagnosed. Their dermatoscopic images were blindly evaluated for the presence of predefined criteria. Descriptive statistics were performed and univariate and multivariate predictors were calculated. Results A total of 68 cases were included, 41 of which were BCCs and 27 SCCs. Most tumours in both groups were non‐pigmented, ulcerated and displayed a polymorphous vascular pattern. The presence of erosions was positively associated to BCC (5.2‐fold higher odds, P = 0.05), whereas scales/keratin masses were positively associated to SCC (3.7‐fold higher odds, P = 0.07), although marginally not statistically significant. Conclusions Clinically misclassified BCCs and SCCs are usually non‐pigmented ulcerated tumours. Erosions and keratin masses/scales are more robust criteria as compared to vascular structures for the differential diagnosis between BCC and SCC.

Real‐life data on basal cell carcinoma treatment: Insights on clinicians' therapeutic choices from an institutional hospital registry

“…As a routine procedure in our center, a clinical and dermoscopic diagnosis of BCC is usually adequate to warrant a direct treatment, while the pretreatment confirmation of the diagnosis with a partial biopsy is only optional for the attending clinician. This is mainly associated with the introduction and widespread use of dermoscopy, which is known to significantly improve the clinical recognition of BCC 12‐15 . Indeed, our results revealed that in 77.5% of tumors the final treatment was applied based only on clinical and dermoscopic diagnosis.…”

“…The small number of pretreatment diagnostic biopsies is also explained by the fact that dermoscopy allows the recognition of very small BCCs, rendering the partial sampling of the tumor meaningless 15‐17 . Indeed, the mean tumor diameter in our cohort was 8.9 mm.…”

Effectiveness and tolerability of treatment for isolated actinic keratoses: A retrospective comparison between cryotherapy, CO 2 laser and 5‐fluorouracil 0.5%/salicylic acid 10%

“…32,33 Additionally, it can identify the first signs of invasive SCC, typified by the presence of dotted vessels around hair follicles, as well as in situ SCC, in which dotted/coiled vessels evolve into glomerular vessels and the follicular openings miniaturize and finally disappear. 34,35 In doubtful cases, histopathological evaluation or reflectance confocal microscopy (RCM) may be useful. RCM presents good accuracy in AK diagnosis and it has been used both in monitoring AK treatment and in the evaluation of the field of cancerization.…”

High‐frequency ultrasound for differentiation between high‐risk basal cell carcinoma and cutaneous squamous cell carcinoma

“…However, the visual presentations of cSCC are quite similar to those of some high‐risk BCC forms, including infiltrative, micronodular, sclerodermiform, morpheaform, and basosquamous subtypes 3 . They present with ulcerations, local destruction, and telangiectasia, resulting in difficult diagnosis and even misdiagnosis 4,5 . Misdiagnosis resulting from similar‐looking lesions may lead to delayed treatment, higher medical cost, and functional and esthetic problems for patients.…”