Basal cell carcinoma (BCC) is the most common malignant tumor of the skin, with a nearly 2-fold increase in incidence rates over the last two decades. A punch biopsy is considered the primary diagnostic tool for BCC; however, recent studies have reported favorable sensitivity and specificity of dermoscopy as a diagnostic tool for this malignancy. Diagnosis of BCC using the “Menzies criteria” was associated with high sensitivity, and surgery performed immediately after clinico-dermoscopic diagnosis was associated with a high positive predictive value.Therefore, in view of the high diagnostic accuracy, positive predictive value, and cost-effectiveness, direct surgical treatment without preoperative biopsy may serve as a primary therapeutic strategy for BCCs that present with typical clinico-dermoscopic features. We report two cases of BCC in patients who underwent successful Mohs microsurgery without preoperative biopsy, using dermoscopy as a primary diagnostic tool.

Background: Dermatofibroma is a common benign skin neoplasm that is usually easy to recognize; however, in some cases, it is difficult to differentiate it from atypical dermatofibroma. Atypical dermatofibroma is a rare variant of a more aggressive nature and requires complete excision due to its tendency to recur. Objective: To describe the clinical and dermoscopic features of dermatofibromas with special emphasis on the characteristics of atypical subtypes and to differentiate them from typical subtypes on the basis of results. Methods: We retrospectively searched the databases of patients of Korea University Ansan Hospital from January 2010 to December 2019 who underwent skin biopsies or excision surgeries and had pathological reports of dermatofibroma. Analyses of the clinical characteristics (age, sex, number of lesions, anatomical site) and dermoscopic patterns were performed. Results: Dermoscopic patterns were analyzed in 148 cases of dermatofibroma; peripheral delicate pigment networks and central white scar-like patches were the most common patterns found in 45 cases (30.4%). In eight cases of atypical dermatofibroma, three cases (37.5%) showed peripheral homogenous areas and central white networks, followed by multiple white scar-like patches in 2 cases (25.0%), peripheral delicate pigment networks, and central white scar-like patches in 2 cases (25.0%). Dermoscopy revealed a statistically significant difference in the peripheral homogenous area and the central white network pattern between the two groups. Conclusion In this study, we analyzed the dermoscopic findings of 148 patients with dermatofibroma and found that the peripheral homogenous area and central white network patterns were significantly more in atypical dermatofibroma.

Transposable elements (TEs) constitute approximately half of Bovine genome. They can be a powerful species-specific marker without regression mutations by the structure variation (SV) at the time of genomic evolution. In a previous study, we identified the Hanwoo-specific SV that was generated by a TE–association deletion event using traditional PCR method and Sanger sequencing validation. It could be used as a molecular marker to distinguish different cattle breeds (i.e., Hanwoo vs. Holstein). However, PCR is defective with various final copy quantifications from every sample. Thus, we applied to the droplet digital PCR (ddPCR) platform for accurate quantitative detection of the Hanwoo-specific SV. Although samples have low allele frequency variation within Hanwoo population, ddPCR could perform high sensitive detection with absolute quantification. We aimed to use ddPCR for more accurate quantification than PCR. We suggest that the ddPCR platform is applicable for the quantitative evaluation of molecular markers.