Poland Syndrome CoexistingWith Blaschkolinear CongenitalMelanocytic Nevi

Those who support the connective tissue origin will further dividemucinousnevi into 2histopathologic types: a connective tissuenevusof theproteoglycan (CTNP) typeandcombinedepidermal-CTNPtype.1 InCTNP, theepidermis isnormal, while in epidermal-CTNP, the epidermis shows hyperkeratosis and acanthosis with elongation of the rete ridges consistentwithanepidermalnevus.1Regardlessof classification, the origin of increased mucin is unclear. Although mucin is synthesized by fibroblasts, previous studies have shown only a slight increase in activated fibroblasts. Thus, some have postulated that the upregulation of fibroblasts is responsible for the increased mucin.3 Clinically, these lesionscanbehardtodistinguishfromconnective tissue nevi such as collagenomas or elastomas. Histologic examination is essential to exclude these entities, which can be associated with congenital abnormalities. The microscopicdifferential diagnosis is narrowand includes focal cutaneousmucinosisandlichenmyxedematosus,bothofwhichhave distinct clinical presentations. Lesionsof focal cutaneousmucinosis areusually solitarypapulesandcanbe foundanywhere on the body. Lichenmyxedematosus presentswith a slow onset of asymptomatic or slightly pruritic papules, which can be generalized or localized. Generalized subtypes of lichen myxedematosushaveanassociatedmonoclonalgammopathy,while discrete papular lichenmyxedematosus, a variant of the localized subtype, has been associated with human immunodeficiencyvirusdisease.6Otherhistologicmimics, like self-healing papular mucinosis and acral persistent papular mucinosis, are easilyexcludedwithclinical information.Inourcase,clinicalcorrelation confirmed the rare diagnosis ofmucinous nevus. Treatment for amucinous nevus is not required owing to its benign nature. Surgical intervention may remove the lesion, but scarring will result.