Acquired Dermal Melanocytosis Research Articles

A Case Series With Acquired Dermal Melanocytosis: A Retrospective Study From 2001 to 2018.

Acquired dermal melanocytosis (ADM) is a pigmented lesion caused by melanocytes in the dermis, and it is most often observed on the face of young and middle-aged Asian women. ADM development may be associated with melanin synthesis alterations, but little evidence of its molecular and histological alteration has yet been reported. This study aimed to evaluate ADM in different body locations using different immunohistochemical and chemical staining techniques. This retrospective case series includes consecutive patients confirmed as ADM by biopsy between 2001 and 2018. Patient data and archival images were used to determine the pattern and duration of skin lesions, as confirmed by data analysis of immunohistopathological staining of skin biopsy specimens. A total of 22 ADM patients were included with mean age at diagnosis of 47 years, and 63.6% were female. The most common site was limbs (36.4%), followed by face (27.3%), trunk (22.7%), and scalp (13.6%). Melanin levels were highest in the face and upper extremities and lowest in the trunk. All participants had perivascular distribution of dermal melanocytes, particularly on the face and limbs. The perineural distribution of dermal melanocytes was observed in the lower limbs, with prominent inflammation and fibrosis on the scalp. Dermal melanocytes expressed most markers recognizing melanocytes except for CD117. Analysis of this ADM case series has confirmed that melanin is activated by dermal melanocytes that may aggregate along blood vessels. CD117 may be a useful biomarker by which to identify the migration of epidermal melanocytes.

Combination treatment algorithm for pigmentary disorders of the face: A prospective observational study in Asian patients

Most patients with facial pigmentary disorders have multiple disorders. However, there is no definitive treatment algorithm improving various pigmentary disorders simultaneously. To investigate the clinical efficacy and safety of the combination of the Q-switched alexandrite and the carbon dioxide lasers with ZO SKIN HEALTHⓇ for facial pigmentary disorders. This prospective observational study enrolled 251 patients with at least one facial pigmentary disorder. We assessed treatment efficacy and investigated which disorders were most responsive to combination treatment and the relationship between doctors' skills, outcomes, and dropout rates. There were 246 patients with lentigo senilis, 186 with moles, 79 with melasma, 53 with seborrheic keratosis, 17 with acquired dermal melanocytosis (ADM), and 16 with freckles. Overall, 227 patients completed treatment. Post-treatment outcomes were excellent in 97, good in 113, fair in 17, and poor in 0 patients. Freckles were the most responsive, and ADM was the least responsive. Patient withdrawal and treatment outcomes did not differ significantly based on the doctors' skills. Overall, 3.2% of patients had adverse events. Our combination algorithm improved several pigmentary disorders of the face simultaneously, regardless of the doctors' proficiency level.

Histopathological features of acquired dermal melanocytosis

Acquired dermal melanocytosis (ADM) is the term used for pigmentary disorders characterized by blue brown macules, most frequently seen on the face (acquired bilateral nevus of Ota-like macules, ABNOM), and rarely found on the trunk or extremities. Although extrafacial ADM and ABNOM are not usually considered separate entities because of similar features, there has been debate as to whether extrafacial ADM and ABNOM might be part of the same disease spectrum, with or without the same pathogenesis. In order to investigate the relationship between these two entities, the histopathological features of extrafacial ADM and ABNOM were evaluated. We examined nine cases of extrafacial ADM and ten cases of ABNOM. Biopsies were performed on both normal and lesional skin, or on lesional skin only. The sections were stained using hematoxylin-eosin, Fontana-Masson, and NKI/beteb. There was no difference in the degree of melanin pigmentation and the number of melanocytes per unit area in the lesional skin of the epidermis and dermis in the comparisons between extrafacial ADM and ABNOM. The mean depth of the dermal melanocytes was significantly increased in extrafacial ADM (0.88 +/- 0.19 mm) compared to ABNOM (0.58 +/- 0.19 mm); however, in both extrafacial ADM and ABNOM, dermal melanocytes were distributed from the upper to the mid dermis. In conclusion, there was no significant difference in the histopathological features, including relative depth of melanocytes, between extrafacial ADM and ABNOM. To the best of our knowledge, this is the first study to demonstrate by histopathology that extrafacial ADM is the same as ABNOM.

Acquired Dermal Melanocytosis: A Case with Conjunctival and Gingival Pigmentation

A 28-year-old Japanese woman was referred to us because of widespread bilateral blue-gray and brown pigmentation on her face. Pigmentation was apparant on both sclerae, the alae of the nose, the lower lip and the gingiva; and it was also evident on her extremities. A biopsy specimen revealed melanin-containing cells and numerous mononulear cells in the upper dermis, particularly, near the small vessels. The melanin-containing cells immunoreacted with S100-specific antibodies but did not react with CD68-specific antibodies, these observations indicated that they were melanocytes. A diagnosis was made of acquired dermal melanocytosis (ADM), even though ADM is very rarely associated with conjunctival and mucosal involvement. Dermal melanocytes and large numbers of mononuclear cells adjacent to small vessels in the upper dermis have not previously been reported in ADM. Such melanocytes might play an important role in protecting blood cells from ultraviolet light. The presence of mononuclear cells close to melanocytes suggests that an inflammatory reaction might have initiated the activation of these dermal melanocytes.

Effects of Ultraviolet Light on Melanocyte Differentiation: Studies with Mouse Neural Crest Cells and Neural Crest‐derived Cell Lines

To evaluate the etiologic role of ultraviolet (UV) radiation in acquired dermal melanocytosis (ADM), we investigated the effects of UVA and UVB irradiation on the development and differentiation of melanocytes in primary cultures of mouse neural crest cells (NCC) by counting the numbers of cells positive for KIT (the receptor for stem cell factor) and for the L-3,4-dihydroxyphenylalanine (DOPA) oxidase reaction. No significant differences were found in the number of KIT- or DOPA-positive cells between the UV-irradiated cultures and the non-irradiated cultures. We then examined the effects of UV light on KIT-positive cell lines derived from mouse NCC cultures. Irradiation with UVA but not with UVB inhibited the tyrosinase activity in a tyrosinase-positive cell line (NCCmelan5). Tyrosinase activity in the cells was markedly enhanced by treatment with alpha-melanocyte-stimulating hormone (alpha-MSH), but that stimulation was inhibited by UVA or by UVB irradiation. Irradiation with UVA or UVB did not induce tyrosinase activity in a tyrosinase-negative cell line (NCCmelb4). Levels of KIT expression in NCCmelan5 cells and in NCCmelb4 cells were significantly decreased after UV irradiation. Phosphorylation levels of extracellular signal-regulated kinase 1/2 in cells stimulated with stem cell factor were also diminished after UV irradiation. These results suggest that UV irradiation does not stimulate but rather suppresses mouse NCC. Thus if UV irradiation is a causative factor for ADM lesions, it would not act directly on dermal melanocytes but may act in indirect manners, for instance, via the overproduction of melanogenic cytokines such as alpha-MSH and/or endothelin-1.

Acquired dermal melanocytosis: Appearance during pregnancy

We report the first case of acquired dermal melanocytosis (ADM) appearing during pregnancy. A 23-year-old Hispanic woman presented to the Dermatology Clinic of Columbia-Presbyterian Medical Center during the second trimester of pregnancy with a nonpalpable blue-gray patch with interspersed discrete brown macules on the right lower extremity. It had appeared during the first trimester of pregnancy. Cutaneous biopsy specimens revealed dermal melanocytes. A review of all reported cases of this rare dermatosis in the international literature is presented. (J Am Acad Dermatol 2001;45:609-13.)

Clinical, pathological, and etiologic aspects of acquired dermal melanocytosis.

To study the pathogenesis of acquired dermal melanocytosis (ADM), we reviewed the clinical, immunohistochemical, and ultrastructural features of 34 cases (female, 33, and male, 1) of ADM. The patients' ages at onset ranged from 8 to 51 years and averaged 26.8 +/- 12.7 years. There was a positive family history. Gray-brown macules were mostly recognized on the face. Not only active dermal melanocytes but also non-pigmented c-KIT- and TRP-2-positive immature melanocytes were detected in the dermis. Taken together those clinical and histological findings, activation of pre-existing immature melanocytes by sunlight, estrogen, and/or progesterone, and some other factors, may be the most likely mode of the development of ADM. Moreover, using cultured murine neural crest cells as a model of c-KIT-positive immature melanocytes, we confirmed that endothelin-1, which is produced and secreted by keratinocytes after UV-irradiation, affects melanocytes and accelerated melanogenesis.