Expression of leucocyte common antigen and epithelial membrane antigen in plasmacytic malignancies

Anaplastic carcinoma of the nose and paranasal sinuses. Light microscopy, immunohistochemistry and clinical correlation

Twenty-one cases of anaplastic carcinoma of the nasal cavity and paranasal sinuses were diagnosed by conventional light microscopy and the use of monoclonal antibodies to epithelial membrane antigen and cytokeratin. Lymphomas and malignant melanomas were excluded by immunohistochemical staining for leukocyte common antigen and S100 protein respectively. The median survival time for these patients was only 1 year despite all forms of treatment. Two patients survived for a longer period and their cases had unusual pathologic features that may have influenced the prognosis.

Metastatic thymoma: a case report and immunohistological analysis

A patient with metastatic lymphocyte predominant thymoma was studied and an immunohistological analysis of frozen and paraffin sections was performed. The immunophenotype of the lymphoid cells was similar to that of primary thymomas and T cell lymphoblastic lymphomas. The epithelial cells reacted with an anticytokeratin monoclonal antibody. The results have diagnostic implications for the histopathologist using immunohistochemistry as a diagnostic aid and it is concluded that a panel of monoclonal antibodies against both lymphoid and epithelial markers should be used for immunohistological typing of tumours of uncertain histogenesis.