An acral lentiginous melanoma (ALM) is the most common type of cutaneous melanoma in Asians. However, it is unusual to encounter a patient showing only the histologic features of an ALM in situ. Here we describe clini...An acral lentiginous melanoma (ALM) is the most common type of cutaneous melanoma in Asians. However, it is unusual to encounter a patient showing only the histologic features of an ALM in situ. Here we describe clinical and histologic features of nine cases of ALM in situ including immunohistochemical staining with anti-S 100 protein and HMB-45. All the patients had a long clinical history. Clinically, the lesions were characterized by a longitudinal pigmented streak in the nail plates, black pigmentation on the proximal or lateral nail fold, and an irregular border and variegated pigmentation on the sole or thumb. Total resections of the lesions were performed in all patients. All lesions, in both biopsy and excisional specimens demonstrated more melanocytes generally located in the basal layer of the epidermis. There was no dermal invasion. No recurrence of the disease had occurred in any patient after a follow-up period of between 6 months to 12 years after surgery. These results suggest that ALM can evolve slowly over many years.展开更多
Epidermal melanin reduces some effects of UV radiation,the major cause of skin cancer. To examine whether induced melanin can provide protection from sunburn injury,65 subjects completed a trial with the potent synthe...Epidermal melanin reduces some effects of UV radiation,the major cause of skin cancer. To examine whether induced melanin can provide protection from sunburn injury,65 subjects completed a trial with the potent synthetic melanotropin, [Nle4-D-Phe7]-α-melanocyte-stimulating hormone ([Nle4-D-Phe7]-α-MSH) delivered by subcutaneous injection into the abdomen at 0.16 mg/kg for three 10-day cycles over 3 months. Melanin density, measured by reflectance spectroscopy, increased significantly in all [Nle4-D-Phe7]-α-MSH-treated subjects. The highest increases were in volunteers with lowest baseline skin melanin levels. In subjects with low minimal erythemal dose (MED) skin type,melanin increased by an average of 41%(from 2.55 to 3.59, P< 0.0001 vs placebo)-over eight separate skin sites compared with only 12%(from 4.18 to 4.70,P< 0.0001 vs placebo) in subjects with a high-MED skin type. Epidermal sunburn cells resulting from exposure to 3 MED of UV radiation were reduced by more than 50%after [Nle4-D-Phe7]-α-MSH treatment in the volunteers with low baseline MED. Thymine dimer formation was also shown to be reduced by 59%(P=0.002) in the epidermal basal layer. This study has shown for the first time the potential ability of a synthetic hormone that augments melanin production to provide photoprotection to people who normally burn in direct sunlight.展开更多
Skin-infiltrating T lymphocytes are thought to play a major role in the pathogenesis of cutaneous lupus erythematosus (CLE). In this study, we investigated the role of the chemokine receptor 4 (CCR4) and its ligand th...Skin-infiltrating T lymphocytes are thought to play a major role in the pathogenesis of cutaneous lupus erythematosus (CLE). In this study, we investigated the role of the chemokine receptor 4 (CCR4) and its ligand thymus-and activation-regulated chemokine (TARC/CCL17) for the recruitment of T cells in inflamed skin of patients with CLE. We found significant numbers of CCR4+T lymphocytes in the skin of all patients with CLE. Interestingly, a subset of patients with disseminated scarring skin involvement were characterized by both lesional and circulating CD8+T cells expressing CCR4. Destruction of epidermal and adnexal structures was histomorphologically associated with CCR4+cytotoxic T cells invading basal layers of the epidermis where keratinocytes showed apoptotic death. The CCR4 ligand TARC/CCL17 was strongly expressed in skin lesions and elevated in the serum of CLE patients. The functional relevance of lymphocytic CCR4 expression could be confirmed by TARC/CCL17-specific in vitro migration assays. Our investigations suggest that CCR4 and TARC/CCL17 play a role in the pathophysiology of CLE. In particular, cytotoxic CD8+T cells expressing CCR4 appear to be involved in scarring subtypes of CLE.展开更多
文摘An acral lentiginous melanoma (ALM) is the most common type of cutaneous melanoma in Asians. However, it is unusual to encounter a patient showing only the histologic features of an ALM in situ. Here we describe clinical and histologic features of nine cases of ALM in situ including immunohistochemical staining with anti-S 100 protein and HMB-45. All the patients had a long clinical history. Clinically, the lesions were characterized by a longitudinal pigmented streak in the nail plates, black pigmentation on the proximal or lateral nail fold, and an irregular border and variegated pigmentation on the sole or thumb. Total resections of the lesions were performed in all patients. All lesions, in both biopsy and excisional specimens demonstrated more melanocytes generally located in the basal layer of the epidermis. There was no dermal invasion. No recurrence of the disease had occurred in any patient after a follow-up period of between 6 months to 12 years after surgery. These results suggest that ALM can evolve slowly over many years.
文摘Epidermal melanin reduces some effects of UV radiation,the major cause of skin cancer. To examine whether induced melanin can provide protection from sunburn injury,65 subjects completed a trial with the potent synthetic melanotropin, [Nle4-D-Phe7]-α-melanocyte-stimulating hormone ([Nle4-D-Phe7]-α-MSH) delivered by subcutaneous injection into the abdomen at 0.16 mg/kg for three 10-day cycles over 3 months. Melanin density, measured by reflectance spectroscopy, increased significantly in all [Nle4-D-Phe7]-α-MSH-treated subjects. The highest increases were in volunteers with lowest baseline skin melanin levels. In subjects with low minimal erythemal dose (MED) skin type,melanin increased by an average of 41%(from 2.55 to 3.59, P< 0.0001 vs placebo)-over eight separate skin sites compared with only 12%(from 4.18 to 4.70,P< 0.0001 vs placebo) in subjects with a high-MED skin type. Epidermal sunburn cells resulting from exposure to 3 MED of UV radiation were reduced by more than 50%after [Nle4-D-Phe7]-α-MSH treatment in the volunteers with low baseline MED. Thymine dimer formation was also shown to be reduced by 59%(P=0.002) in the epidermal basal layer. This study has shown for the first time the potential ability of a synthetic hormone that augments melanin production to provide photoprotection to people who normally burn in direct sunlight.
文摘Skin-infiltrating T lymphocytes are thought to play a major role in the pathogenesis of cutaneous lupus erythematosus (CLE). In this study, we investigated the role of the chemokine receptor 4 (CCR4) and its ligand thymus-and activation-regulated chemokine (TARC/CCL17) for the recruitment of T cells in inflamed skin of patients with CLE. We found significant numbers of CCR4+T lymphocytes in the skin of all patients with CLE. Interestingly, a subset of patients with disseminated scarring skin involvement were characterized by both lesional and circulating CD8+T cells expressing CCR4. Destruction of epidermal and adnexal structures was histomorphologically associated with CCR4+cytotoxic T cells invading basal layers of the epidermis where keratinocytes showed apoptotic death. The CCR4 ligand TARC/CCL17 was strongly expressed in skin lesions and elevated in the serum of CLE patients. The functional relevance of lymphocytic CCR4 expression could be confirmed by TARC/CCL17-specific in vitro migration assays. Our investigations suggest that CCR4 and TARC/CCL17 play a role in the pathophysiology of CLE. In particular, cytotoxic CD8+T cells expressing CCR4 appear to be involved in scarring subtypes of CLE.
