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A 33-year-old Malaysian woman requests removal of a growth on her right hand. The lesion has been present for several years and is asymptomatic but unsightly. She states that an older brother has a similar lesion. Examination reveals an 0.8-cm dome-shaped, blue-black nodule of the affected area. Axillary lymph nodes are nonpalpable, and full body skin examination is otherwise unremarkable.
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Blue nevi most commonly present as solitary blue to blackish papules or nodules. These lesions are composed of ectopic collections of dermal melanocytes believed to form when melanocytes fail to complete their migration from the neural crest to the dermoepidermal junction.1 Uncommon variants present as discrete and widely disseminated papules or grouped together in a single cluster.2 Histology reveals dermal proliferation of spindle or ovoid cells and melanin pigment inside melanocytic cells and macrophages that are positive for HMB-45 (Gp100), S-100, and Melan-A/MART-1 expression.3
Melanoma arising from a blue nevus has been reported but is a rare phenomenon.4,5 Biopsy of an atypical appearing lesion is recommended; a majority of lesions are readily diagnosed clinically and removed for cosmesis.
Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.
References
- Suchniak JM, Griego RD, Rudolph AH, Waidhofer W. Acquired multiple blue nevi on an extremity. J Am Acad Dermatol. 1995;33:1051-1052.
- Knoell KA, Nelson KC, Patterson JW. Familial multiple blue nevi. J Am Acad Dermatol. 1998;39:322-325.
- Daltro LR, Yaegashi LB, Freitas RA, Fantini BC, Souza CD. Atypical cellular blue nevus or malignant blue nevus? An Bras Dermatol. 2017;92:110-112.
- Connelly J, Smith JL Jr. Malignant blue nevus. Cancer. 1991;67:2653-2657.
- Granter SR, McKee PH, Calonje E, Mihm MC Jr, Busam K. Melanoma associated with blue nevus and melanoma mimicking cellular blue nevus: a clinicopathologic study of 10 cases on the spectrum of so-called ‘malignant blue nevus’. Am J Surg Pathol. 2001;25:316-323.
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