Blue nevi

From dermoscopedia

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 Authored by: Josep Malvehy     ·  Susana Puig

 Keywords:   blue nevus · naevus bleu · combined nevus
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Description Describes dermoscopyDermoscopy is a non invasive diagnostic method. criteriaThis glossary term has not yet been described. of blue neviThis glossary term has not yet been described.
Author(s) Josep Malvehy · Susana Puig
Owner Josep Malvehy→ send e-mail
Status released
Status update August 31, 2017
Status by Ralph P. Braun
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Blue nevusThis glossary term has not yet been described. also known as "blue neuronevus", "dermal melanocytoma", and "nevus bleu" is a type of melanocyticThis glossary term has not yet been described. nevusThis glossary term has not yet been described.. The blue colour is caused by the melanin pigment being deeper in the skin than in ordinary nevi. Blue nevus commonly arise in adulthood but in some cases they are present at birth or during the first year of life. Diffuse melanocytosis are clinical variants of blue nevi characterized by the development of blue diffuse pigmentation, many years after birth, on the faceThis glossary term has not yet been described. (Ota nevus), on the trunk or arms (Ito nevus), on the sacrum area (Mongolian spot).


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Clinical characteristics

A blue nevusThis glossary term has not yet been described. presents a regular form, homogenously pigmented (blue to brownish-blue, grey-blue or black-blue) lesions. They can be macules, papules, plaques or nodules.


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Dermoscopic features

Dermoscopic features of blue nevus are defined by a homogeneous patternA pattern lacking any definable pigment structures, structureless pattern with homogeneous blue pigmentation and complete lack of other features such as pigment network or black/brown dots or globules within the lesion. The absence of local features and the presence of a well-defined border are suggestive of blue nevus in contrast to primary melanomaThis glossary term has not yet been described.. Homogeneous blue pigmentation is the dermoscopic hallmark of blue nevi but in some exceptional cases they may exhibit blue globules and dotsThis glossary term has not yet been described.. The presence of fibrosis in sclerotic type blue nevus can be seen as a hypo pigmented area with whitish or grey coloration. On the face, perifollicular blue/brown hyperpigmentation can also be seen associated with the homogeneous blue pigmentation.

A combined nevusThis glossary term has not yet been described. with a blue nevus component and a dermal nevus component shows a characteristic image with brown homogeneous pigmentation associated with blue homogeneous pigmentation in the same lesion. In blue and combined nevus streakslines, radial (always at periphery) Reed nevus, melanoma, recurrent nevus at the periphery can be seen by the presence of radially oriented bundles of melanocytic cells or melanin-laden macrophages. In contrast with the streaks at the periphery of melanoma or Spitzoid/Reed type melanocytic lesions in blue nevus these structures show a slate-blue pigmentation and are out of focus due to their depth.

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In the nevus of Ota and nevus of Ito a diffuse irregular blue-brownish pigmentation is the main dermoscopic feature.

Dermoscopic Differential diagnosisThis glossary term has not yet been described. of blue nevus

  • Some nodular melanomas and malignantThis glossary term has not yet been described. blue nevus can clinically and dermoscopically resemble a blue nevus. In the case of the malignant tumours the diameter is usually larger due to their fast growth.
  • A subtype of melanoma epidermotropic metastasis are undistinguishable of blue nevus due to the pigmentation at the dermal level. In this malignant condition the clinical history of previous melanoma and the presentation of multiple new blue lesions are relevant for the differential diagnosis.
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  • Tattoos used in radiotherapy and by cosmetics reasons exhibit a blue coloration that in dermoscopy is composed by blue dots that can be distinguished of the blue homogeneous pigmentation of blue nevi.
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  • Vascular lesions exhibit a typical dermoscopy pattern with red, blue or purple black clods without vascular features. However some vascular lesions be exhibit a blue homogeneous pattern.
  • Finally some rare pigmented basal cell carcinomas with large blue ovoid nests may mimic a bleu nevus. Usually in these lesions multiple clods and other dermoscopic features characteristic of basal cell carcinomais the most common skin cancer, and one of the most common cancers in the United States.[1] While BCC has a very low metastatic risk, this tumor can cause significant disfigurement by invading surrounding tissues such as branched vesselsarborizing vessels Bright red sharply in focus large or thick diameter vessels dividing into smaller vessels BCC are present

ManagementThis glossary term has not yet been described. 

Blue nevi are benignThis glossary term has not yet been described. lesions and no treatment or follow-up is needed. The history of recent change or the evidence of increase in size or change in structure demonstrated by digital follow up is the clue for not missing melanoma blue nevus like.

References

  • Malvehy,j, Puig S, Braun R,et al. Handbook of dermoscopy. Taylor and Francis 2009.
  • Granter SR, McKee PH, Calonje E, Mihm MC, Busam K (March 2001). "MelanomaThis glossary term has not yet been described. 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. PMID 11224601. doi:10.1097/00000478-200103000-00005.
  • Cabral ES, Chen FW, Egbert BM, Swetter S. Acquired blue nevi in older individuals: retrospective case series from a Veterans Affairs population, 1991 to 2013. JAMA Dermatol.;150(8):873-6.
  • Garrido-Ríos AA, Carrera C, Puig S, Aguilera P, Salerni G, Malvehy J. Homogeneous blue patternThis benign pattern is frequently seen in blue nevus in an acralAcral melanoma is a type of skin cancer that occurs on fingers, palms, soles, and nail beds. congenital melanocytic nevus. Dermatology. 2008;217(4):315-7
  • Loghavi 1, Curry J1, Torres-Cabala CA, Ivan D1, Patel KP, Mehrotra M, Bassett 3, Prieto VG1, Tetzlaff MT. Melanoma arising in association with blue nevus: a clinical and pathologic study of 24 cases and comprehensive review of the literature. Mod Pathol.;27(11):1468-78.
  • Yonei N, Kimura A, Furukawa F.Common blue nevus with satellite lesions needs a differential diagnosis from malignant melanoma. Case Rep Dermatol. 5;5(3):244-7
  • Daltro LR, Yaegashi L2, Freitas RA, Fantini BC, Souza C. Atypical cellular blue nevus or malignant blue nevus? An Bras Dermatol.;92(1):110-112.
  • Jonjić N, Dekanić A, Glavan N, Prpić-Massari L, Grahovac B. Cellular Blue Nevus Diagnosed following Excision of Melanoma: A Challenge in DiagnosisThis glossary term has not yet been described.. Case Rep Pathol. 2016;2016:8107671.
  • Costa J, Ortiz-Ibañez K, Salerni G, Borges V, Carrera C, Puig S, Malvehy J. Dermoscopic patterns of melanoma metastases: interobserver consistency and accuracy for metastasis recognition. Br J Dermatol. 2013 Jul;169(1):91-9