Angulated lines
Angulated lines are geometrical lines in a zig-zag pattern, which may coalesce forming polygons. These structures are called rhomboids or zig-zag pattern (Kittler et al., 2016a) when observed in the face or neck and are associated with lentigo maligna (LM) (Schiffner et al., 2000; Slutsky and Marghoob, 2010). In other locations, the angulated lines appear to be larger than the rhomboids seen in LM and are highly suspicious of lentiginous melanomas from chronically sun-exposed skin (Jaimes et al., 2015). Histologically, the polygonal nature of these lines is still unknown. However, angulated lines seem to correspond to a flattened dermoepidermal junction (DEJ) with fewer and more blunted rete pegs due to a proliferation of atypical melanocytes at the DEJ together with a focal accumulation of melanophages in the superficial dermis. (Vanden Daelen et al., 2016). [1]
