Shave biopsy for differential diagnosis of lentigo maligna on the face and scalp: diagnostic approach

Abstract

Lentigo maligna is a subtype of melanoma in situ, which affects sun-exposed areas. On the face, it can have a clinical and dermoscopic appearance similar to several benign pigmented lesions. Differential diagnosis between them is fundamental for the appropriate therapeutic and should be made by histopathological analysis. Excisional biopsy is the gold standard, but in large, unresectable lesions or in difficult anatomical sites, it can have aesthetic or functional implications. In these cases, shave biopsy appears to be a safe and reliable alternative. Objective: To describe an appropriate shave biopsy technique, discuss its results and indications in the outpatient routine of the dermatologist. Methods: Sixteen patients with suspected : Lentigo maligna on the face and scalp were selected. Inclusion criteria were older than 18 years, lack of diagnosis and previous treatment, flat lesions larger than 8 mm and suggestive clinical and dermatoscopic signs. The approach performed was shave biopsy. Results: The diagnosis of : Lentigo maligna was confirmed in 25% of the cases, and a widening of margins presented compatible results in 100% of them. Conclusions: Shave biopsy seems to be a suitable alternative for flat lesions without clinical and dermoscopic criteria of vertical growth