Annular pigmented actinic keratosis mimicking lentigo maligna melanoma in a 75-year-old female: An unusual presentation

Pigmented actinic keratosis (PAK) is an uncommon variant of actinic keratosis that can mimic different pigmented lesions, which may be benign or malignant. The diagnosis of PAK is often challenging because of overlapping features with lentigo maligna melanoma (LMM). Clinically, lesions of both conditions almost look similar; the diagnoses must be established histologically and with the help of immunostaining whenever needed. The distinction between a large PAK and LMM is important because their prognosis and management differ. We present a 75-year-old female with annular brown-to-black-colored maculo-plaque on forehead having clinical suspicious of melanocytic malignancy; which was diagnosed with a PAK on biopsy with help of histopathology and confirmed with Melan A/MART‑1 immunostaining.

A Misdiagnosed Case of Anal Canal Malignant Melanoma: A Case Report.

Anal canal malignant melanoma is an uncommon malignancy. It is a highly aggressive tumor that tends to spread early in the course and present with distant metastasis. Due to the rarity of the condition, treatment is yet to be standardized. We report a case of a 47-y ear-old male patient who presented with the history of mass coming out of anus for 6 months, which was misdiagnosed as a case of hemorrhoids. Abdominoperineal resection was done based on tissue biopsy which suggested it to be a primary anal canal malignant melanoma. The diagnosis was later confirmed by histopathological and immunohistochemistry studies, which was strongly positive for HMB 45 AND Melan-A.

Hepatic perivascular epithelioid cell tumor (PEComa): a case report with a review of literatures

Hepatic perivascular epithelioid cell tumors (PEComas) are very rare. We report a primary hepatic PEComa with a review of the literature. A 56-year-old women presented with a nodular mass detected during the management of chronic renal failure and chronic hepatitis C. Diagnostic imaging studies suggested a nodular hepatocellular carcinoma in segment 5 of the liver. The patient underwent partial hepatectomy. A brown-colored expansile mass measuring 3.2×3.0 cm was relatively demarcated from the surrounding liver parenchyma. The tumor was mainly composed of epithelioid cells that were arranged in a trabecular growth pattern. Adipose tissue and thick-walled blood vessels were minimally identified. A small amount of extramedullary hematopoiesis was observed in the sinusoidal spaces between tumor cells. Tumor cells were diffusely immunoreactive for human melanoma black 45 (HMB45) and Melan A, focally immunoreactive for smooth muscle actin, but not for hepatocyte specific antigen (HSA).

OAZI-1 enhances the immunogenicity of Melan-A vaccine in mice / 基础医学与临床

Objective To investigate whether ornithine decarboxylase antizyme inhibitor-1(OAZI-1) can enhance the immunogenicity of Melan-A and induce antitumor immune effect in the experimental animals.Methods The eukaryotic expression plasmid pcDNA3.1(-) /OAZI-1, pcDNA3.1 (-)/Melan-A and pcDNA3.1(-)/Melan-A-OAZI-1 were constructed and used to immunize BALB/c mice.The spleen lymphocytes were prepared from the immunized mice and then used to determine the lymphocyte subsets by flow cytometry assay and tumor-killing activity by LDH release assay.The blood samples were collected from the immunized mice and used to test the serum INF-γ by ELISA.Results The eukaryotic expression plasmid pcDNA3.1(-)/OAZI-1, pcDNA3.1(-)/Melan-A and pcDNA3.1(-)/Melan-A-OAZI-1 were successfully constructed.All three gene vaccines could increaseCD4+ T cell ratio (P<0.05), among of them, the ratio in the pcDNA3.1(-)/Melan-A-OAZI-1 and pcDNA3.1(-)/Melan-A immunized groups increased more significantly than other groups but no obvious differences was observed between these two groups.Similarly, all three gene vaccines could also increased CD8+T cells ratio significantly (P<0.05), but, comparing with all other groups, the highest increase was observed in the pcDNA3.1(-)/Melan-A-OAZI-1 immune group (P<0.05).The pcDNA3.1(-)/Melan-A-OAZI-1 gene vaccines significantly increased cytotoxic activity of the spleen lymphocyte in the immune mice(P<0.05).Among the three gene vaccines only pcDNA3.1(-)/Melan-A-OAZI-1 could significantly increased the INF-γ level in the mice serum (P<0.05).Conclusions OAZI-1 can improve antitumor immunity by promoting tumor antigen presentation.

Modulation of Melanin Synthesis by Amaranthus spp. L Seed Extract in Melan-a Cells

Anti-melanogenic effects of amaranth (AT), one of the key source of squalene, were investigated in melanocytes. Amaranth seed powder was extracted with water and melan-a cells were treated with various concentrations of AT. By using HPLC, content of myo-inositol, one of potential active components, was measured in the crude extract of AT.AT reduced the melanin content in melan-a melanocytes and down-regulated melanogenic enzyme activity such as tyrosinase, TRP-1 and TRP-2. By regulating melanogenic enzyme activity, AT may be a potential natural source for whitening agent. Myo-inositol was detected in AT by HPLC and may be one of the active compounds from AT involved in the regulation of anti-melanogenesis. In this study, we demonstrated that AT has anti-melanogenesis properties. This new function of amaranth may be useful in the development of new skin-whitening products and its value as food.

Immunohistochemical Double Staining of Ki-67/Melan-A in Melanocytic Nevi and Malignant Melanomas / 대한피부과학회지

BACKGROUND: Melanomas need to be differentiated from benign melanocytic lesions during diagnosis. However, it is difficult to differentiate them using histopathology alone, since both neoplasms have broad morphological spectrums and subtle differentiating features. OBJECTIVE: To evaluate the usefulness of Ki-67/Melan-A double staining for differentiating melanoma from benign melanocytic nevi. METHODS: We selected 20 cases of intradermal nevi, 20 cases of compound nevi, 5 cases of dysplastic nevi, and 25 cases of melanoma from clinicopathologically proven cases reviewed by the Department of Dermatology at our medical center. Ki-67/Melan-A double staining was performed, and the Melan-A verified Ki-67 index (Ki-67-M index) and Ki-67 index were measured. The immunopositivity was measured in the deepest third of the lesions. RESULTS: The Ki-67-M index of intradermal nevi, compound nevi, dysplastic nevi, and melanoma were 0.4+/-0.9%, 1.0+/-1.1%, 4.3+/-1.7%, and 24.1+/-10.9%, respectively. The best Ki-67/Melan-A cut-off point to distinguish melanomas from benign melanocytic nevi was 5%; the sensitivity and specificity were 100% and 97.7%, respectively. Immunopositivity in the deepest third of the intradermal nevi, compound nevi, and melanoma, were 10.5%, 20%, and 100%, respectively; the sensitivity and specificity for diagnosing melanoma were 100% and 84.6%, respectively. The sensitivity and specificity of combined Ki-67-M and immunopositivity in the deepest third for diagnosing melanoma were 100% and 97.7%, respectively. CONCLUSION: The Ki-67-M index and immunopositivity in the deepest third of melanoma were significantly higher than that of benign melanocytic nevi. Therefore, Ki-67/Melan-A double staining is a potentially valuable diagnostic tool for differentiating melanoma from benign melanocytic nevi.

Imuno-histoquímica para o diagnóstico precoce de vitiligo / Immunohistochemistry for early diagnosis of vitiligo

O vitiligo é uma doença de pele freqüente que acomete 1% da população e é caracterizada por máculas despigmentadas conseqüentes à perda progressiva e localizada dos melanócitos da epiderme. Na maioria dos pacientes, o diagnóstico é feito por exame clínico. A biópsia da pele é realizada quando há necessidade de diagnóstico diferencial com doenças hipocromiantes. O diagnóstico histopatológico de vitiligo é difícil nos preparados corados por hematoxilina e eosina (HE). Há poucos estudos sobre a melhoria da qualidade diagnóstica no vitiligo. OBJETIVO: Avaliar a utilidade dos marcadores imuno-histoquímicos proteína S-100, human melanoma black-45 (HMB-45) e Melan-A para o diagnóstico precoce em casos clinicamente suspeitos ou duvidosos de vitiligo. Material e métodos: Lâminas histológicas de biópsias de pele sã e lesada de 10 pacientes com suspeita clínica de vitiligo coradas pelos métodos de HE, proteína S-100, HMB-45 e Melan-A. Utilizou-se contracoloração com Giemsa como modificação técnica para diferenciar a melanina da imunomarcação. RESULTADOS: Seis casos, com manifestação clínica recente, apresentaram infiltrado linfocitário, do tipo dermatite de interface, na pele lesada na HE. As colorações por S-100, HMB-45 e Melan-A marcaram os melanócitos da camada basal da pele sã, e a proteína S-100 evidenciou as células de Langerhans. Na pele lesada, os melanócitos estavam ausentes ou diminuídos quando comparados com a pele normal. A proteína S-100 demonstrou maior número de células de Langerhans, o que é característico das lesões de vitiligo. CONCLUSÃO: A imuno-histoquímica pode ser utilizada como método auxiliar no diagnóstico dos casos duvidosos de vitiligo.

Vitiligo is a frequent skin disease that affects 1% of the population. It presents depigmented macules resulting from a gradual loss of melanocytes in the epidermis. In most cases, the diagnosis is made by clinical examination. Skin biopsies are performed when it is necessary to compare it with other hypomelanosis. Histopathological diagnosis of vitiligo is often difficult in hematoxylin-eosin (H&E) stained sections. There are a few studies on the improvement of diagnostic quality in vitiligo. OBJECTIVE: To evaluate the use of immunohistochemical markers, such as S-100 protein, human melanoma black-45 (HMB-45) and Melan-A, in the early diagnosis of clinically suspected or doubtful cases of vitiligo. Materials and methods: Histological sections of biopsies from healthy and affected skin areas from 10 patients clinically suspected of vitiligo. The samples were stained with H&E, S-100 protein, HMB-45 and Melan-A methods. Counterstaining with Giemsa was applied as a technical modification to differentiate melanin from immunolabelling. RESULTS: Six cases with recent clinical manifestation showed lymphocyte infiltrates, such as interface dermatitis, in the affected skin in the H&E staining technique. S-100 protein, HMB-45 and Melan-A staining marked the basal layer melanocytes of the healthy skin and S-100 protein antigen evidenced Langerhans cells. Melanocytes were absent or less frequent in affected skin areas in comparison with normal skin. S-100 protein showed a larger number of Langerhans cells, what is a common feature of vitiligo lesions. Conclusion: Immunohistochemistry may be used as an auxiliary technique for the diagnosis of suspected vitiligo cases.

Immunohistochemical Study of Malignant Melanoma with HMB-45, Antibodies against S100 Protein, Melan-A, and Tyrosinase / 대한피부과학회지

BACKGROUND: Immunohistochemical confirmation is needed to correctly diagnose malignant melanoma, due to its heterogeneous histological appearance. OBJECTIVE: In the diagnosis of malignant melanoma, we evaluated the usefulness of recently introduced antibodies against Melan-A and tyrosinase, and compared them with antibodies against S100 protein and HMB-45. METHOD: Immunohistochemical staining with the above 4 antibodies was performed on 36 cases of malignant melanoma which had been excised. The percentage of positive tumor cells with the semi-quantitative estimation were than graded as follows; 0% = grade 0, 1-25% = grade 1, 26-50% = grade 2, 51-75% = grade 3, 76-100% = grade 4. We regarded grade 0 as negative, and grade 1 to 4 as positive. The association of Breslow thickness with the individual grade of 4 antibodies was then evaluated. RESULTS: 1. Positiveness of the 4 antibodies were as follows; 100% of the antibody against S100 protein, 97.2% of HMB-45, 97.2% of the antibody against tyrosinase, 91.7% of the antibody against Melan-A. 2. A case of a HMB-45 negative melanoma showed a grade 4 for the antibody against S100 protein, a grade 2 for the antibody against Melan-A, and a grade 3 for the antibody against tyrosinase. 3. The Breslow thickness had a significant positive correlation with the individual grade of antibody against Melan-A. CONCLUSION: In combination with the antibody against S100 protein and HMB-45, the newly developed antibodies against Melan-A and tyrosinase may be useful in the diagnosis of malignant melanoma.

Numerical Changes of Melanocytes in Artificial Epidermis Reconstructed by Keratinocytes and Melanocytes Coculture / 대한해부학회지

To follow up the change of melanocytes to keratinocytes ratio in stratified epidermis reconstructed by mixed culture of these cells, the author investigated the ratio of melanocyte to keratinocyte in the basal layer of reconstructed epidermis after induction of stratification for 1 week with cocultured melanocyte and keratinocyte in various ratio. Initial mixing ratios of melanocyte to keratinocyte were 1 : 10, 1 : 20, 1 : 40, 1 : 80. Post ratios were changed to 1 : 6.7, 1 : 10.7, 1 : 12.6, 1 : 13.8 respectively after 1 week. Eight time of initial gap reduced to two times and melanocyte to keratinocyte ratio converged to 1 : 10. To know the regulation mechanism, the author investigated the ratio of basal melanocytes to suprabasal melanotytes. The ratios were nearly same by showing 0.142, 0.140, 0.118, 0.104 respectively. These results suggest that the ratio of melanocyte to keratinocyte in reconstructed stratified epidermis in vitro was not related with initial mixing ratio and was regulated by proliferation of melanocytes controled by corresponding keratinocytes.