Multiple blue nevi with late appearance

ARTICLE

Auteur(s) : Francisco Manuel Almazán-Fernández, María Antonia Fernández-Pugnaire, María Victoria Guiote, Jesús Hernández-Gil, Salvio Serrano-Ortega

Servicio Dermatología Hospital Clínico San Cecilio, Avda. Madrid sn, 18012 Granada, Spain

Blue nevus is a benign melanocytic neoformation, originating from dermal melanocytes which have stopped their migration from the neural crest to the epidermis during the fetal period. It manifests as well-defined papules, nodules, or maculae, located on the back of the hands, feet or head, but multiple locations have been reported (cervix, oral mucosa, vagina, sclera…) [1]. They become evident in early childhood or adolescence with a prevalence rate of 0.5-4% in Caucasians. When they appear in adulthood and are multiple, they may be part of the Carney complex. We report two patients, 51 and 64 years old, with multiple acquired blue nevi.

A male, 51 years old, without relevant history, consulted about the recent gradual appearance of an asymptomatic pigmented lesion on the scalp. The patient denied trauma or burns in that area. We observed > 10 blue, plane, symmetrical tumors with well defined borders, distributed in the left front-parieto-occipital region (figure 1A). Digital dermoscopy showed a characteristic homogeneous blue pattern (figure 1B). A detailed physical examination, complete analytical and body-CT ruled out other injuries or associated systemic disease. The pathological study confirmed the clinical suspicion of common blue nevi (figure 1C). After 3 years of follow-up the patient has not shown malignant lesions.

A female, 67 years old, with a history of hysterectomy and a permanent pacemaker for atrioventricular complete block, consulted for the gradual appearance, over 2 years, of pigmented, blue and asymptomatic lesions localized on the facial region. She had a history neither of trauma nor burns and the injuries appeared > 20 years after the menopause. She had 4 slate-blue, plane and symmetrical tumors, with well defined borders, in the frontal region and on the left cheek (figure 1D). The dermoscopic image was also characterized by a homogeneous blue pattern. We carried out rigorous complementary investigations that revealed no additional information. A biopsy confirmed the diagnosis of common blue nevi. After 4 years of monitoring the patient has not shown malignant lesions.

Blue nevi belong to the circumscribed dermal melanosis group, like Mongolian spot, nevus of Ota or Ito. Histologically, we distinguish 3 types: Common blue nevus, cellular blue nevus and combined blue nevus. The characteristic location of blue nevus is the back of hands and feet, the scalp and sacral region [2]. With dermoscopy, common blue nevus presents a characteristic homogeneous blue or white-blue pattern and the absence of other parameters, such as pigmented network, dots and globules, allowing differentiation from other melanocytic tumors [3].

The eruption of blue nevi has been described during physiological conditions such as puberty or pregnancy, and pathological conditions like after trauma, burns and bullous diseases [2, 4]. Nardini et al. proposed that, in cases without other influences, chronic solar photo-exposure could stimulate proliferation in the dermis of residual melanocytes which present incomplete migration [4].

Multiple blue nevi are rare. They can be part of Carney complex, described in 1985. The most important cutaneous manifestations are lentigines with a centrofacial location, multiple epithelioid blue nevi on the trunk, limbs, and head and junctional and compound nevus [5]. Previously published multiple blue nevi, with late appearance, without associated systemic disease or tumors, are shown in table 1.
Table 1 Previously published multiple blue nevi

We report 2 new cases of eruptive blue nevi appearing in adulthood. If the nevi are epithelioid, it is essential to carry out detailed cutaneous and other examinations (ultrasound for cardiac myxomas, abdominal CT, ultrasound for breast visualization, testes or ovaries, cranial CT and MRI, and complete analytical, and even genetic studies) to rule out a Carney complex. But common blue nevi, in photo-exposed areas, may be a sign of photoaging and we believe they do not require further complementary studies.

Acknowlegements

References

2 William M, Hendricks MD. Eruptive blue nevi. J Am Acad Dermatol 1981; 4: 50-3.

3 Ferrara G, Soyer HP, Malvehy J, et al. The many faces of blue nevus: A clinicopathologic study. J Cutan Pathol 2007; 34: 543-51.

4 Nardini, de Giorgi, Massi, Carli. Eruptive disseminated blue naevi of the scalp. Br J Dermatol 1999; 140: 178-80.

5 Jérôme Bertherat. Carney Comples (CNC). Orphanet Journal of Rare Diseases 2006; 1: 21.