RESUMO
Uveal melanoma is characterized by an unpredictable clinical course, during which metastatic disease may occur after a prolonged and, at present, undefinable disease-free interval. Because of its relative rarity and the dispersion of cases, the possible genetic alterations implicated in the invasive and metastatic behaviour of this ocular neoplasm have not yet been characterized. The aim of this immunohistochemical retrospective study was to assess the expression of nm23 gene product, proposed to be a metastasis-suppressor gene, in uveal melanoma and to analyse its prognostic significance in relation to the various conventional histopathological parameters, currently considered the major prognostic indicators in this intra-ocular neoplasm. We analysed formalin-fixed paraffin-embedded samples excised from 33 patients with uveal melanoma. Of these, 22 (67%) were positive for monoclonal antibody nm23. This nm23 positivity was inversely associated with scleral invasion level (P = 0.001) and largest tumour diameter (P = 0.02), which represent the two most significant prognostic factors for metastasis. On the other hand, there was no correlation between nm23 expression and other prognostic markers such as cell type, intraocular location or clinical characteristics. These results may suggest a close relationship between nm23 gene expression and metastatic potential of uveal melanomas. In addition, analysis of nm23 gene expression on bioptic tissue may represent an extreme useful prognostic tool for metastatic progression of uveal melanomas.
Assuntos
Biomarcadores Tumorais/biossíntese , Imuno-Histoquímica/métodos , Melanoma/metabolismo , Proteínas Monoméricas de Ligação ao GTP , Núcleosídeo-Difosfato Quinase , Fatores de Transcrição/biossíntese , Neoplasias Uveais/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/imunologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Melanoma/genética , Melanoma/patologia , Melanoma/secundário , Pessoa de Meia-Idade , Nucleosídeo NM23 Difosfato Quinases , Prognóstico , Estudos Retrospectivos , Fatores de Transcrição/imunologia , Neoplasias Uveais/genética , Neoplasias Uveais/patologiaRESUMO
The incidence of cutaneous melanoma is constantly rising. Ocular involvement is rare and the choroid is the most accessible structure to metastatic emboli. The case described is noteworthy on account of several particular features: 1) the missed diagnosis of the primary malignancy. This might be because either cutaneous melanoma or cutaneous nevi show several common features; 2) the rarity of the retinal metastatic site. Unlike the choroid, the retina is an unusual metastatic site but, regardless of organ blood flow, the metastatic efficiency may be related to interactions between tumor cells and host tissue; 3) the treatment of the retinal metastasis, excised conservatively. As far as we know, this is the first report of a retinal metastasis being treated by local resection.
