Abstract Background: Basal cell and squamous cell carcinomas (BCC and SCC) are the most common types of cancer worldwide. Intraoperative assessment of surgical margins by frozen section has been widely used to ensure disease-free margins. The intraoperative ‟en face” freezing technique evaluates all peripheral and deep margins. Objective: To report the results of the ‟en face” freezing technique in relation to tumor recurrence and agreement with paraffin-embedded tissue examination. Methods: Retrospective analysis of patients undergoing surgical excision of BCC and SCC at the A. C. Camargo Cancer Center, Brazil. Results: This study included 542 skin carcinomas, which were excised from 397 patients. A total of 201 male patients (50.6%), and 196 female patients (49.4%) were assessed, whose mean age was 64 years. The tumors were mostly located on the head and neck region (87.8%). BCC corresponded to 79.7% of the cases. The mean follow-up was 38 months. Tumor relapse occurred in 0.86% of the primary tumors and 3.7% of recurrent tumors. The result of the intraoperative ‟en face” frozen section evaluation was in agreement with the final result of the anatomopathological examination (paraffin test) in 98% of the lesions. Study limitations: Not having a minimum follow-up time of 5 years for all patients. Conclusion: The ‟en face” freezing technique shows low tumor relapse, being reliable and safe to guarantee negative surgical margins of the tumor.

Abstract Melanoacanthoma is a rare variant of seborrheic keratosis, which is notable for dark pigmentation and fast radial growth, making it difficult to distinguish from melanoma. Histologically, it is characterized by proliferation of keratinocytes and dendritic melanocytes. The authors report a scalp lesion, fast growing, suspected by dermoscopy and confocal microscopy examination, with dendritic cells distributed throughout the lesion. Based on these findings, it was not possible to classify this lesion as clearly benign, so it was excised. Histopathologic evaluation and immunostain were consistent with melanoacanthoma.

Abstract: Proliferating trichilemmal cyst is an uncommon neoplasm arising from the follicular isthmus, whose histopathological hallmark is the presence of trichilemmal keratinization. We describe a case of proliferating trichilemmal cyst in a 57-year-old woman with a broad clinical, radiological, macroscopic and microscopic correlation.

Abstract: Diphencyprone has been reported as a local immunotherapy for cutaneous melanoma metastases. We aim to report cases of melanoma patients treated with diphencyprone in a single Brazilian institution and highlight their outcomes. Since 2012, we have treated 16 melanoma patients with cutaneous metastases with topical diphencyprone. To date, we have had 37.5% of complete response, 25% of partial responses, and 31.25% patients without any response. Treatment was well tolerated and local toxicity was easily controlled. We believe topical diphencyprone is a feasible treatment that can be another option for treating melanoma patients, especially in cases of in-transit or extensive disease.

Abstract Vemurafenib is a selective inhibitor of V600E-mutant BRAF protein used to treat metastatic and unresectable melanoma. Clinical trials have shown increased overall survival and progression-free survival in patients treated with Vemurafenib. However, cutaneous adverse events are common during treatment. We report fi ve cases of metastatic melanoma with BRAF V600E positivity, treated with Vemurafenib and its cutaneous adverse events. Dermatologists and oncologists need to be aware of possible skin changes caused by this medication, which is increasingly employed in melanoma treatment. Monitoring of patients during therapy is important for early treatment of adverse cutaneous cutaneous adverse events, improvement in quality of life and adherence to treatment.