|Description||Describes dermoscopyThe examination of [skin lesions] with a 'dermatoscope'. This traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections. criteriameasure of how well one variable or set of variables predicts an outcome of blue neviThis glossary term has not yet been described.|
|Author(s)||Josep Malvehy · Susana Puig|
|Responsible author||Josep Malvehy → send e-mail|
|Status update||August 31, 2017|
|Status by||Ralph P. Braun|
Blue nevusis a type of melanocytic nevus that clinically and dermoscopically will appear blue 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 faceis a central body region of sense and is also very central in the expression of emotion among humans and among numerous other species. (Ota nevus), on the trunk or arms (Ito nevus), on the sacrum area (Mongolian spot).
BN are benign dermal melanocytic proliferation arising from neural-crest melanocytes that likely became arrested in migration during embryogenesis. Their prevalence ranges between 1-2% in Caucasians and 3-5% in Asians. Typically they first appear in adolescence and young adulthood, even though BN can also arise in older individuals (Cabral et al. 2014). Somatic acquired mutations in GNAQ and GNA11 have been identified in BN (Van Raamsdonk et al. 2010). Clinically, common BN present as a solitary small, well-defined, round to oval shaped, flat to slightly-elevated papule with a predominant steel blue color (spectrum gray-blue-black). They are most often located on the distal extensor aspects of limbs, followed by the face and scalpThis glossary term has not yet been described., and the sacral region. Other less common locations include genitalia, oral cavity, and lymph nodes (Zembowicz 2017). The histopathologic features seen in common BN are highly pigmented bipolar spindle cells parallel to the epidermis intermingled with bundles of collagen in the mid to deep dermis, sometimes even extending to the hypodermis. Typically, there is a grenz zone at the dermoepidermal junction, which remains unaffected. When faced with blue lesions, clinical history remains of great importanceThis glossary term has not yet been described.. Blue nevi lesions arising in childhood and with no history of change are highly suggestive of common BN. In contrast, a new onset and fast-growing lesion in a middle-aged adult, or in the contextThis glossary term has not yet been described. of a previous melanomaThis glossary term has not yet been described., should raise concern for the possibility of melanoma.
The most characteristic pattern of BN is the absence of a pigment networkGrid-like pattern consisting of interconnecting pigmented lines surrounding hypopigmented holes., with homogeneous and structureless blue pigmentation or a combinationThis glossary term has not yet been described. of two colorsThis glossary term has not yet been described.: white-blue, steel blue-gray, blue-brown or blue-black. The pigment is confluent throughout the lesion and fades toward the periphery (figuresThis glossary term has not yet been described. 12). Multichromatic pigmentation has also been described, always including blue in the spectrum (figure 4) (Di Cesare et al. 2012). With the use of polarized lightThis glossary term has not yet been described. dermoscopes additional structuresThis glossary term has not yet been described. are seen: bluish globulesThis glossary term has not yet been described./dotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect)., network-like structuresThis glossary term has not yet been described. or peripheral out-of-focus streakslines radial (always at periphery) streaks Reed nevus melanoma recurrent nevus corresponding to pigmented projections of the nevus cells or melanophages, both deep within the dermis.
A combined nevusBenign nevus with 2 different cell population in the same lesion. Most frequently this refers to a junctional nevua in associatoin with a blue nevus with a blue nevusis a type of melanocytic nevus that clinically and dermoscopically will appear blue 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 streaks 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.
In the nevus of Ota and nevus of Ito a diffuse irregular blue-brownish pigmentation is the main dermoscopic feature.
Dermoscopic Differential diagnosisis the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines with variations in the use of logic, analytics, and experience to determine "cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions of blue nevus
- Some nodular melanomas and malignant 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 presentationThis glossary term has not yet been described. of multiple new blue lesions are relevant for the differential diagnosis.
- 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.
- Vascular lesionsThis glossary term has not yet been described. exhibit a typical dermoscopy pattern with red, blue or purple black clods without vascular features. However some vascular lesionsThis glossary term has not yet been described. be exhibit a blue homogeneous patternA pattern lacking any definable pigment structures, structureless pattern.
- Finally some rare pigmented basal cell carcinomas with large blue ovoid nestsThis glossary term has not yet been described. 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. While BCC has a very low metastatic risk, this tumor can cause significant disfigurement by invading surrounding tissues such as branched vesselsThis glossary term has not yet been described. are present
Blue nevi are benign 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.
- 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 acral 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 Diagnosisis the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines with variations in the use of logic, analytics, and experience to determine "cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions. Case Rep Pathol. 2016;2016:8107671.
- Costa J, Ortiz-Ibañez K, Salerni G, Borges V, Carrera C, Puig S, Malvehy J. Dermoscopic patternsThis glossary term has not yet been described. of melanoma metastases: interobserver consistency and accuracy for metastasis recognition. Br J Dermatol. 2013 Jul;169(1):91-9