Congenital segmental dermal melanocytosis associated with cellular blue nevus

ARTICLE

Auteur(s) : Li Wang¹, Xi-Chuan Yang¹, Fei Hao¹, Zhi- Fang Zai¹, Yan Mei²

¹Department of Dermatology, Southwest Hospital, The third military medical university, 400038 Chongqing, China
²Department of Architecture and Civil Engineering.400040 Chongqing, China

Dermal melanocytosis (DM) is characterized by the presence of ectopic melanocytes in the dermis. There are several classically recognized morphological forms, such as the blue nevus, the mongolian spot, the nevus of Ota, and the nevus of Ito [1]. Moreover, a few cases of dermal melanocytosis have been reported that do not belong to any of the above-mentioned entities. In this article, we report an unusual case of dermal melanocytosis.

A 27-year-old Chinese man was referred to us for his asymptomatic pigmentation on the left aspect of his breast. The patient stated that the pigmentation had been present since birth and grew slowly in the first decade, but with its size, color and texture unchanged in recent years. Over the past 14 years, the patient noticed a slowly enlarging, 2 cm, asymptomatic, dark blue nodule on his left areola papillaris, but there had been no change in its size, color, or texture in the past 8 years. The nodule had been completely surgically removed 20 days before. There was no family history of pigmentary disorders. He was otherwise healthy and on no medication.

Physical examination showed that the bluish patch covered the left aspect of breast in a segmental distribution. The surface was smooth without follicular abnormality. The lesion was heterogeneous in color, with numerous gray-blue maculae giving the lesion a mottled appearance. An incisional scar was seen on the edge of left areola papillaris (figure 1A). The results of sensory examinations were normal. The general physical examination, including a clinical neurological exploration, revealed nothing meaningful except the skin lesion. Data from routine laboratory studies, chest roentgenogram, and findings from an X-ray bone series were normal.

Two biopsy specimens were obtained: the specimen from the pigmentation showed a sparse number of elongated melanocytes that were situated mainly in the middle part of the dermis. A brown pigment filled the cytoplasm of elongated melanocytes (figure 1B). The specimen from the nodule under his left areola papillaris showed a large nodular cellular mass filling the dermis. It had a well circumscribed border and was composed of a dual population of islands of plump spindle or dendritic melanocytes admixed with sclerotic foci. In neither specimen were mitotic figures, pleomorphism or areas of necrosis presented. A great number of melanophages were also observed (figures 1C, D).

Congenital DM with a segmental organization has very rarely been reported [2-5]. In 1992, Vélez et al. reported a 28-year-old white woman with a congenital, extensive, speckled gray-blue pigmentation on the right aspect of her trunk in a segmental pattern, and histological examination revealed sparse, elongated, dermal melanocytes. The authors named this disease “congenital segmental dermal melanocytosis”. The pigmented lesion in our patient is unusual and does not fit into any of the classically recognized forms of dermal melanocytosis; however, it shows pathological and clinical similarities with the lesion of Vélez et al. [5].

The lesion which was surgically removed grossly appeared nodular shaped and 2 cm sized. Histologically it consisted of a fairly well-circumscribed proliferation of a large number of plump spindle or dendritic melanocytes. The cell type and disposition in the nodule are distinguished from segmental DM, which is composed of sparse numbers of elongated melanocytes, situated mainly in the middle part of the dermis. We concluded from the clinical and histopathological findings that the nodule was best classified as a cellular blue nevus [6]. Congenital segmental dermal melanocytosis associated with a cellular blue nevus has not, to the best of our knowledge, been reported before.

Acknowledgements

References

2 Grézard P, Berard F, Balme B, et al. Congenital bilateral dermal melanocytosis with a dermatomal pattern. Dermatology 1999; 198: 105-6.

3 Krishnan RS, Roark TR, Hsu S. Isolated patch of speckled, congenital, pigmented dermal melanocytosis outside the face or acromioclavicular regions. J Eur Acad Dermatol Venereol 2003; 17: 238-9.

4 Kim S, Kim JA, Kim WS, et al. Congenital dermal melanocytosis confined to the palm. J Eur Acad Dermatol Venereol 2007; 21: 1116-7.

5 Vélez A, Fuente C, Belinchon I, et al. Congenital segmental dermal melanocytosis in an adult. Arch Dermatol 1992; 128: 521-5.

6 Bisceglia M, Carosi I, Fania M, et al. Nevus of Ota. Presentation of a case associated with a cellular blue nevus with suspected malignant degeneration and review of the literature. Pathologica 1997; 89: 168-74.