RESUMO
Extramedullary plasmacytoma is defined as neoplastic proliferation of plasma cells in soft tissue. It accounts for up to 3% of all plasma cell tumors. Approximately, 90% of extramedullary plasmacytomas are found in the head and neck region commonly affecting the nasal cavity, paranasal sinuses, tonsillar fossa, and oral cavity. Radiotherapy is the common modality of treatment with or without adjuvant chemotherapy. We report a case of extramedullary plasmacytoma of the gingiva.
Assuntos
Neoplasias Gengivais/patologia , Plasmócitos/patologia , Plasmocitoma/patologia , Biópsia , Células da Medula Óssea/patologia , Diagnóstico Diferencial , Seguimentos , Neoplasias Gengivais/diagnóstico por imagem , Neoplasias Gengivais/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Plasmocitoma/diagnóstico por imagem , Plasmocitoma/radioterapia , RadiografiaRESUMO
The extent of lymph node metastasis is a major determinant in the prognosis of oral squamous cell carcinoma (OSCC). Abnormalities of cell adhesion molecules are known to play an important role in invasion and metastasis of cancer cells through the loss of cell-to-cell adhesion. In this study, we isolated highly invasive clones from an OSCC cell line established from a lymph node metastasis by using an in vitro invasion assay method and compared the abnormalities of cell adhesion molecule E-cadherin and beta-catenin in these cells. The isolated, highly invasive clones showed significant invasive capacity and reduction of E-cadherin and membranous beta-catenin protein in comparison with parent cells. We found that reduced expression of E-cadherin was due to methylation of its promoter region. In fact, most invasive and metastatic area of OSCCs showed reduced expression and methylation of E-cadherin. Moreover, we found that reduced expression of membranous beta-catenin was due to its protein degradation. Reduced expression of membranous beta-catenin was also found frequently in invasive and metastatic areas of OSCCs. In summary, invasion and metastasis of OSCC cells require methylation of E-cadherin and/or degradation of membranous beta-catenin. In addition, we suggest that the method of isolation of highly invasive clones may be useful for studies aimed at discovering novel genes involved in invasion and metastasis.