<prompt> A 24-year -old male presents with a hyperpigmented patch over the right upper chest 4 years ago, thick hair over the same with time. Diagnosis is:Spitz nevusHypermelanosis of ItoBeckers nevusCongenital melanocytic nevus  <response>: Ref. Rooks Textbook of Dermatology, Pg 75 Becker NevusSharply demarcated pigmented macule, often with localized hypertrichosisDermoscopy: network, focal hypopigmentation, skin furrow hypopigmentation, hair follicles, perifollicular hypopigmentation and vesselsSex ratio close to 1:1 Sharply demarcated, unilateral, hyperpigmented tan macule on back, shoulder or chestHypertrichosis in 50 HistopathologyIncreased basal layer pigmentation, mild acanthosis, hyperkeratosis and regular elongation of rete ridgesVariable hypertrichosisAreas associated with smooth muscle hamartoma have more pronounced smooth muscle bundles irregularly dispersed within the dermis and unrelated to either hair follicles or vascular channelsDoes not actually contain nevus cells 