|Micrograph of a blue nevus showing the characteristic pigmented melanocytes between bundles of collagen. H&E stain.|
Blue nevus (also known as "blue neuronevus", "dermal melanocytoma", and "nevus bleu") is a type of melanocytic nevus. The blue colour is caused by the pigment being deeper in the skin than in ordinary nevi. In principle they are harmless but they can sometimes be mimicked by malignant lesions, i.e. some melanomas can look like a blue nevus.
Blue nevi may be divided into the following types::701
- A patch blue nevus (also known as an "acquired dermal melanocytosis", and "dermal melanocyte hamartoma") is a cutaneous condition characterized by a diffusely gray-blue area that may have superimposed darker macules.
- A blue nevus of Jadassohn–Tièche (also known as a "common blue nevus", and "nevus ceruleus") is a cutaneous condition characterized by a steel-blue papule or nodule.:701
- A cellular blue nevus is a cutaneous condition characterized by large, firm, blue or blue-black nodules.:701
- An epithelioid blue nevus is a cutaneous condition most commonly seen in patients with the Carney complex.:701
- A deep penetrating nevus is a type of benign melanocytic skin tumor characterized, as its name suggests, by penetration into the deep dermis and/or subcutis. Smudged chromatic is a typical finding. In some cases mitotic figures or atypical melanocytic cytology are seen, potentially mimicking a malignant melanoma. Evaluation by an expert skin pathologist is advisable in some cases to help differentiate from invasive melanoma.:701
- An amelanotic blue nevus (also known as a "hypomelanotic blue nevus") is a cutaneous condition characterized by mild atypia and pleomorphism.:701
- A malignant blue nevus is a cutaneous condition characterized by a sheet-like growth pattern, mitoses, necrosis, and cellular atypia.:701
- Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 1722. ISBN 1-4160-2999-0.
- "Blue naevus (nevus). DermNet NZ". Retrieved 2009-02-27.
- Blue Nevi at the US National Library of Medicine Medical Subject Headings (MeSH)
- Granter SR, McKee PH, Calonje E, Mihm MC, Busam K (March 2001). "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. 25 (3): 316–23. doi:10.1097/00000478-200103000-00005. PMID 11224601.
- James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.