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Benign Neoplasms
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Abdullah Demirbaş, Ömer Faruk Elmas, Necmettin Akdeniz
Laboratory studies: Histologically, the dermis contains darkly pigmented bipolar dendritic cells and melanophages extending parallel to the epidermis. Melanocytes will stain positive with HMB-45, Melan A, MITF-1, and S-100. The common blue nevus is associated with nests and fascicles of spindle-shaped cells with abundant pale cytoplasm containing little or no melanin.
Ultrastaging of the sentinel node
Published in Charles F. Levenback, Ate G.J. van der Zee, Robert L. Coleman, Clinical Lymphatic Mapping in Gynecologic Cancers, 2022
Celien P.H. Vreuls, Ate G.J. van der Zee, Paul J. van Diest
For squamous cell carcinoma metastases, AE1/3 is a reliable antibody. It has high specificity and sensitivity. Van den Brekel et al.63 found additional non-SN lymph node metastases in 3/13 head and neck squamous cell carcinoma patients (23%) with this antibody. This antibody can also be used for squamous gynecologic cancer; however, its yield appears to be modest, as described in the previous paragraph. For melanoma, a combination of a sensitive marker (S100) and a specific marker (Melan A, MART1, tyrosinase) can be recommended.
Invasive Tests
Published in Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan, Comprehensive Textbook on Vitiligo, 2020
Hemant Kumar Kar, Gunjan Verma
Skin biopsy samples can also be examined by Melan-A (A103 clone)+ for melanocyte expression by immunohistochemical analysis and for melanin by histochemical studies with section staining by Fontana-Masson method. Melan-A+ cells and melanin granules were detected in depigmented skin as indication that the residual melanocytes are preserved in vitiligo lesions. More than threefold decrease of Melan-A+ melanocytes amount was revealed in perilesional normally pigmented skin of vitiligo patients [3].
Matched analysis of the prognosis of amelanotic and pigmented melanoma in head and neck
Published in Acta Oto-Laryngologica, 2020
Wei Guo, Gaofei Yin, Hongfei Liu, Hanyuan Duan, Zhigang Huang, Xiaohong Chen
The histopathological diagnosis of melanoma is based on the identification of intracellular melanin. Therefore, it is often difficult to make a final diagnosis of non-pigmented lesions, and tumour cells are diverse in morphology. These cell types can present epithelioid, fusiform, plasmacytoid, rhabdomyoid or polynuclear morphology alone or in combination [13]. It is difficult to make a definite diagnosis of AM during intraoperative freezing, and an immunohistochemical study is necessary to make a definite diagnosis. Immunohistochemical staining is very valuable for diagnosis, especially for S100, HMB-45 and Melan-A. The sensitivity of S100 was 97–100%, but the specificity was 75–87% [14]. Melan-A is a highly sensitive and specific marker, especially for cutaneous malignant melanoma and its metastasis, but it is inferior to HMB-45 in non-cutaneous malignant melanoma [15]. It has been reported [16] that HMB-45 may be more sensitive to primary oral and nasal melanoma than any other marker because it shows significantly higher staining intensity.
Natural options for management of melasma, a review
Published in Journal of Cosmetic and Laser Therapy, 2018
Mulberry extract is a Morus alba L. derivative plant from Moraceae family. The root bark has been found to have skin depigmenting effects due to its inhibitory action of dopa oxidase activity of tyrosinase and its superoxide scavenging activity (53). An in vitro investigative study looked at the effects of compounds found in dried mulberry leaves on melanin biosynthesis (79). The result of this study was significant as cultured melan-a cells responded positively. It was discovered that dried mulberry leaves have an inhibitory effect on tyrosinase action and on melanin formation in melan-a cells (79). A randomized clinical trial investigated 75% topical mulberry oil compared to a placebo in the treatment on melasma (80). Results demonstrated that mulberry was a safe and effective lightening agent with added antioxidant benefits with mild side effects such as itching (Table 3).
Melanocytes and keratinocytes morphological changes in vitiligo patients. A histological, immunohistochemical and ultrastructural analysis
Published in Ultrastructural Pathology, 2022
Raghda Elsherif, Waleed Ahmed Mahmoud, Refaat R Mohamed
Antibodies directed against Melan-A protein markers used in the identification of melanocytes. Avidin-Biotin peroxidase technique was used according to O’Callaghan and Jensen.19 The primary antibodies used for immunohistochemical staining were mouse antihuman polyclonal Melan-A antibodies (Novocastra Laboratories Ltd., UK) at a dilution of 1:25 in phosphate buffer solution (PBS) and left-over night at room temperature. Then, sections were stained with an avidin-biotin-peroxidase system with diaminobenzidine as the chromogen. Then, sections were washed in distilled water and counterstained with hematoxylin. Melan-A positive cells have dark brownish cytoplasmic staining.