Basosquamous carcinoma (BSC) is a relatively rare type of neoplasm originating from basal cell carcinoma with features of squamous differentiation. BSC has an aggressive local behaviour with a tendency for recurrence and a less frequent metastatic potential The primary objective was to describe the dermatoscopic features of the tumour. Secondary goals were to detect the morphological features of the tumour along with patients' characteristics and to evaluate possible dermatoscopic and histopathological correlations Twenty-two patients with 25 BSCs were enrolled. All tumours were surgically excised and diagnosis was based on histopathology. Clinical and dermatoscopic images were evaluated by two investigators based on pre-defined criteria, and a statistical analysis was performed The median age of the patients was 78 years old (range: 52-88) and the male/female ratio was 2.14. All patients reported history of either occupational (50%) or recreational (50%) intensive sun exposure and 72.73% had signs of actinic keratosis. The most common anatomical site of the tumours was the head/neck area (72%). Clinically, nodular (64%), ulcerated (88%) and non-pigmented (76%) lesions prevailed. Dermatoscopically, 92% had prominent vasculature and monomorphous arborizing vessels with a diffuse arrangement, representing the most frequently observed type. Ulceration (88%), SCC dermatoscopic criteria (56%), white strands/blotches (56%) and features of pigmentation (40%) were also detected We suggest that the most common prototype of BSC is an ulcerated, facial nodule in elderly males with photo-damaged skin, dermatoscopically displaying combined features of mostly nodular BCC and, to a less extent, SCC.
Keywords: basosquamous; dermatoscopy; histopathology; metatypical basal cell carcinoma; squamous cell carcinoma.