Imuno-histoquimica para identificacao de celulas neoplasicas no infiltrado ativo de melanomas finos



Título del documento: Imuno-histoquimica para identificacao de celulas neoplasicas no infiltrado ativo de melanomas finos
Revista: Jornal brasileiro de patologia e medicina laboratorial
Base de datos: PERIÓDICA
Número de sistema: 000297269
ISSN: 1676-2444
Autores: 1
Instituciones: 1Universidade Estadual Paulista "Julio de Mesquita Filho", Faculdade de Medicina, Botucatu, Sao Paulo. Brasil
Año:
Periodo: Abr
Volumen: 42
Número: 2
Paginación: 143-148
País: Brasil
Idioma: Portugués
Tipo de documento: Artículo
Enfoque: Caso clínico, analítico
Resumen en inglés Thin melanomas are frequently associated with brisk lymphocytic infiltrate. Pigmented melanocytes are difficult to distinguish from melanophages, which are usually seen interspersed among lymphocytes on routine hematoxylin and eosin (HE) stained slides. As the presence of melanocytes in the papillary dermis characterizes the lesion as Clark II requiring the Breslow index, it is important to identify these cells properly and overcome such technical limitations. Even using immunohistochemistry staining for Melan-A and DAB as chromogens, this distinction is still difficult because the brown pigment formed by the chromogen DBA can not be easily differentiated from the brown melanin granules. We have introduced a simple modification on the technique, by replacing hematoxylin with Giemsa as counterstain. In this regard, the melanin pigment was decorated in green-blue while the Melan-A positive melanocytes were colored brown. Negatively stained melanophages contain only course green-blue granules of melanin in their cytoplasm. Thus, we were able to identify Melan-A positive cells in the papillary dermis accurately, determining microinvasion (Clark II) in 31 (77,5%) out of 40 in situ (Clark I) melanomas associated with brisk infiltrate. This technique is useful to distinguish melanophages and melanocytes interspersed among the lymphocytic infiltrate associated to thin melanomas, allowing detection of early invasion and avoiding Clark levels and Breslow index misinterpretation
Resumen en portugués A técnica apresentada permite, portanto, diferenciar macrófagos e melanócitos dispersos no infiltrado linfocitário associado a melanomas finos, permitindo detectar invasão inicial, evitando interpretação errônea do nível de Clark e da medida de Breslow
Disciplinas: Medicina
Palabras clave: Dermatología,
Oncología,
Inmunología,
Melanoma,
Inmunohistoquímica,
In situ,
Técnicas de laboratorio
Keyword: Medicine,
Dermatology,
Oncology,
Melanoma,
Immunohistochemistry,
In situ,
Laboratory techniques,
Immunology
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