First documented in 1948 by U.S. dermatologist Samuel William<unk>  (1894-1964),<unk>  (also<unk> ; pl. nevi or naevi) is a skin disorder predominantly affecting males.  The<unk>  generally first appears as an irregular pigmentation (melanosis or hyperpigmentation) on the torso or upper arm (though other areas of the  body can be affected), and gradually enlarges irregularly, becoming thickened and often hairy (hypertrichosis).  It is also known as<unk><unk> ,<unk> 's pigmented hairy<unk> ,<unk>  pigmented hairy<unk> ,<unk>  melanosis and pigmented hairy epidermal<unk> .
Becker's nevus
Riehl's melanosis
Halo nevus
Bowen's disease
Acral nevus
Bowen’s disease
Prosector's wart
Blue nevus