DP17 Mercedes-Benz-like sign

Abstract We report the case of a 99-year-old man with a 2-year history of progressively elongating, linear, crusted lesions at the base of his midline thoracotomy scar. These lesions originated from a coronary artery bypass graft performed over two decades earlier The patient experienced no associated symptoms. On clinical examination, two linear nodular lesions, each approximately 5 mm in size, were observed spreading laterally on either side of the thoracotomy scar with straight edges. Dermoscopic evaluation revealed arborizing vessels and blue-grey globules, findings consistent with the rare linear basal cell carcinoma (BCC) subtype. The patient underwent excisional biopsy performed by the plastic surgery team. Histological analysis confirmed the diagnosis of ulcerated BCC of the nodular type. There was no evidence of perineural invasion or deeper tissue involvement. The lesions were fully excised with adequate peripheral and deep margins. Linear BCC is a rare variant first described in 1985, with only a handful of cases reported since (Lewis JE. Linear basal cell epithelioma. Int J Dermatol 1985; 24: 124–5). This rarity may stem from under-recognition and misclassification into more common subtypes such as nodular or superficial BCCs. Linear BCC typically presents as an elongated lesion, frequently seen in the periocular region or neck, with a characteristic length-to-width ratio of at least 3 : 1. Several factors may contribute to its development, including trauma, koebnerization, dermal fibrosis and alignment with relaxed skin tension lines. Histological findings from previously reported cases indicate a higher proportion of the infiltrative and morphoeic subtypes, suggesting an elevated risk profile. Notably, no cases of metastatic spread have been documented to date (Navarrete-Dechent CP, Marchetti M, Uribe P et al. Dermoscopy of linear basal cell carcinomas, a potential mimicker of linear lesions: a descriptive case series. Dermatol Pract Concept 2022; 12: e2022195).