Comparative dermatology: blue nevus

Dermatologia comparativa: nevo azul

ICONOGRAPHY

Comparative dermatology: blue nevus^*

Dermatologia comparativa: nevo azul

Jefferson Alfredo de Barros^I; Cristiane Calcidoni Kafler^II; Juliano Cesar de Barros^I; Rodrigo Sestito Proto^III; Priscila dos Santos Costa^II; Carlos D'Apparecida Machado Filho^IV

^IM.Sc. in Health Sciences, ABC School of Medicine (Faculdade de Medicina do ABC) - Teaching Assistant of Dermatology, ABC School of Medicine - Santo André (SP), Brazil

^IIPhysician - Resident in Dermatology, ABC School of Medicine - Santo André (SP), Brazil

^IIIM.Sc. in Health Sciences, ABC School of Medicine - Santo André (SP), Brazil

^IVProfessor and Coordinator of the discipline of Dermatology, ABC School of Medicine - Santo André (SP), Brazil

^{Mailing address}

ABSTRACT

There are elements in nature that may be compared to some dermatological lesions, such as the black pearl, which is very similar to a cellular blue nevus observed in the gluteus region of a 31-year-old male patient.

Keywords: Nevus, blue; Skin diseases; Skin neoplasms

RESUMO

A natureza pode oferecer elementos passíveis de comparação com algumas lesões dermatológicas, como a semelhança entre a pérola negra e o nevo azul celular observado na região glútea de paciente do sexo masculino, 31 anos.

Palavras-chave: Dermatopatias; Neoplasias cutâneas; Nevo azul

Black pearls are the rarest kind of pearl found in nature. They grow in the waters of French Polynesia, where the oysters named Pinctada margaritifera, also known as the black-lipped oysters, are found. A pearl is formed when a strange body (such as a grain of sand) is deposited inside the bivalve of an oyster, between the mantle and the shell, causing an intense inflammatory process. The oyster reacts producing a secretion composed of nacre, which builds up in thin concentric layers that overlap originating "pearlescence" (i.e., a nacreous glow) (Figure 1).^1,2

In many ways, the black pearl is similar to the lesion found in a 31-year-old male patient, grayishbrown skin, who presented a bluish-brown, clearly defined, rounded, moderately firm, nodular tumor in his gluteus region, measuring 4.5 cm, and compatible with giant cellular blue nevus, confirmed by microscopic examination (Figure 2). We opted for the surgical excision of the lesion.

The blue nevus is a neoplasm composed of melanocytes in the reticular dermis. It can be congenital or acquired. The global rate of affected individual is around 3%. Microscopically, it is characterized by the presence of long, thin, often corrugated melanocytes, grouped to form irregular bundles predominantly in the upper dermis, parallel to the epidermis.³ It usually affects the skin, though it can also affect other regions such as the uterine cervix, vagina, spermatic cord, oral mucosa, prostate and lymph nodes.⁴ They often come alone.³ They can be clinically divided into (i) common - they appear during the first years of life, measuring 2 to 10 mm, found mainly on the limbs and face, and (ii) cellular - measuring more than 10 mm, appearing as firm nodules, mainly on the gluteus and sacrococcygeal regions, casually observed at birth, potentially undergoing malignant evolution, with indication for surgical removal^3,4 Some authors describe a third, very rare clinical form, named combined blue nevus, characterized by the overlapping of microscopic aspects of both blue and melanocytic nevus.⁵

Received on 13.02.2012.

Approved by the Advisory Board and accepted for publication on 30.03.2012.

Financial support: None.

Conflict of interest: None.

• 1. How Stuff Works -A Discovery Company [homepage on the Internet]. "How do oysters make pearls?" [cited 2007 Ago 23]. Available from: http://animals.howstuffworks.com/marine-life/question630.htm
• 2. Thongnopkun P, Ekgasit S. Characterization of dyed pearls by FT-IR spectroscopy and FT-RAMAN spectroscopy. KMITL Sci J. 2008;8. (Section B, July - December).
• 3. Murali R, McCarthy SW, Scolyer RA. Blue nevi and related lesions: a review highlighting atypical and newly described variants, distinguishing features and diagnostic pitfalls. Adv Anat Pathol. 2009;16:365-82.
• 4. Hanna A, Rawal S, Anderson KM, Rawal YB. The epithelioid blue nevus: a rare intraoral nevomelanocytic tumor. J Oral Maxillofac Pathol. 2011;15:88-90.
• 5. Corrêa LA, Carneiro FR, Meireles VMB, Miranda MFR. Nevo azul combinado gigante: relato de caso. An Bras Dermatol. 1998;73:225-8.

*

Work conducted as a requirement for the discipline of Dermatology, ABC School of Medicine, Santo André - São Paulo (SP), Brazil.

Publication Dates

• Publication in this collection
  10 Aug 2012
• Date of issue
  Aug 2012

History

• Received
  13 Feb 2012
• Accepted
  30 Mar 2012