Synonyms: Tièche-Jadassohn naevus, Jadassohn-Tièche naevus, common blue naevus, cellular blue naevus, chromatophoroma, melanofibroma
A blue naevus is a small blue- or grey-coloured lesion of the skin, with an appearance similar to a mole. They derive their blue colour from their pigmentation with melanin and relatively deep position within the epidermis. One theory of their origin is that they represent embryonic neural crest cells that have failed to migrate into the epidermis in the usual fashion. There are two forms:
Common blue naevus
- The most common form, 2-7 mm in diameter.
- Slightly raised and smooth lesion with macular, papular or plaque-like appearance.
- Grey-blue to bluish-black in colour.
- Does not have any malignant potential.
- Usually a solitary lesion with a predilection for the head (especially the scalp), neck, sacral area and dorsum of the hands/feet.
Cellular blue naevus
- Much rarer than the common form.
- Larger lesion, often 1-3 cm in diameter.
- Raised lesions with a smooth surface.
- The same colour as the common form.
- Often solitary and found on the buttocks, sacral region and the back of the hands/feet.
- Large blue naevi on the trunk have been reported with cellular changes similar to a melanoma although metastases have never been reported.
- Blue naevi are present from a young age, but relatively unusual at birth (estimated prevalence ~1 in 1,000).
- They are at their most common in Asian populations, with a prevalence of 3-5% among adults. Prevalence in white populations is roughly 1-2%.
- They are around twice as common in women as they are in men.
- They usually arise during the second decade and do not change in shape or size thereafter.
- Rarely, they can be present from birth.
- If the cellular form of the lesion undergoes malignant transformation this usually manifests as a precipitate increase in size or, more rarely, ulceration.
- They can be found as pigmented lesions at unusual sites - eg, the female genitourinary tract, beneath nails, spermatic cord, bronchus, lymph nodes and prostate. Blue naevi found in the oral mucosa are rare but can have tendency to malignancy.
- Malignant melanoma.
- Melanocytic naevus.
- Combined naevus.
- Compound naevus.
- Tattooing effect (deliberate, or material accidentally pushed into the skin during trauma - eg, coalminer's tattoo, ink pens).
- Thrombosed plantar wart.
- Apocrine hydrocystoma.
- Kaposi's sarcoma.
- Congenital naevus.
- Granuloma telangiectaticum.
- Naevi of Ota and Ito.
- Carney's syndrome/complex is a rare association of blue naevi with further abnormalities of the skin and other organs, inherited in an autosomal dominant fashion.
- It causes cardiac, endocrine, cutaneous and neural myxomatous tumours, plus a variety of pigmented lesions of the skin and mucosae.
- None is usually required.
- If the nature of a lesion is uncertain then dermoscopy may be performed by a dermatologist to distinguish it from melanomatous lesions.
- Occasionally even dermoscopy is insufficient and biopsy may be required.
- A technique called fluorescence in situ hybridisation (FISH) assay is sometimes needed to diagnose cellular blue naevi from blue naevus-like melanoma.
- Typical lesions that have the appropriate history, that have not changed in size or shape and where there are no other features that would suggest an alternative diagnosis, or the presence of melanoma, can be left alone, and the patient reassured.
- However, as for any pigmented lesion, where there is doubt as to the diagnosis, it is safest to perform excision biopsy or refer for dermatological advice.
- Where the history is atypical, or the lesion has changed, refer for advice or perform excision biopsy.
- There are occasional reports of recurrence of the lesion in a satellite form after excision; such lesions must be examined by further excision biopsy, preferably with dermatological opinion, to exclude malignant transformation.
- Common blue naevi do not have any complications, are benign, and persist unchanged throughout life.
- Cellular blue naevi are also usually benign but may, rarely, undergo malignant transformation.
- Cellular naevi are larger and so more likely to present and undergo excision biopsy.
- The prognosis for both types of lesion is excellent.
- In the rare cases where cellular naevi become malignant then prognosis is improved by earlier diagnosis, as for melanoma.
Further reading & references
- Improving Outcomes for People with Skin Tumours including Melanoma, NICE (Update May 2010)
- Tièche-Jadassohn naevus; Whonamedit.com
- Roth RR et al; Blue Nevi, Medscape, Jan 2012
- North JP, Yeh I, McCalmont TH, et al; Melanoma ex blue nevus: two cases resembling large plaque-type blue nevus with subcutaneous cellular nodules. J Cutan Pathol. 2012 Dec;39(12):1094-9. doi: 10.1111/cup.12015. Epub 2012 Nov 12.
- Craddock KJ, Bandarchi B, Khalifa MA; Blue nevi of the Mullerian tract: case series and review of the literature. J Low Genit Tract Dis. 2007 Oct;11(4):284-9.
- Fitzhugh VA, Houck K, Heller DS; Vaginal blue nevus: report of a case and review of the literature. J Low Genit Tract Dis. 2011 Oct;15(4):325-7. doi: 10.1097/LGT.0b013e318213f3b8.
- Santos Tde S, Frota R, Martins-Filho PR, et al; Extensive intraoral blue nevus--case report. An Bras Dermatol. 2011 Jul-Aug;86(4 Suppl 1):S61-5.
- Blue Nevus; DermIS (Dermatology Information System), 2013
- American Osteopathic College of Dermatology, Blue Nevus, 2013
- Carney Complex, Type 1: CNC1; Online Mendelian Inheritance in Man (OMIM)
- Di Cesare A, Sera F, Gulia A, et al; The spectrum of dermatoscopic patterns in blue nevi. J Am Acad Dermatol. 2012 Aug;67(2):199-205. doi: 10.1016/j.jaad.2011.08.018. Epub 2011 Oct 26.
- Gammon B, Beilfuss B, Guitart J, et al; Fluorescence in situ hybridization for distinguishing cellular blue nevi from blue nevus-like melanoma. J Cutan Pathol. 2011 Apr;38(4):335-41. doi: 10.1111/j.1600-0560.2010.01667.x. Epub 2011 Jan 19.
|Original Author: Dr Sean Kavanagh||Current Version: Dr Laurence Knott||Peer Reviewer: Prof Cathy Jackson|
|Last Checked: 11/02/2013||Document ID: 4063 Version: 23||© EMIS|
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