Expression of C-myc p62 oncoprotein in multiple myeloma: an immunohistochemical study of 180 cases.

The immunohistochemical expression of C-myc p62 oncoprotein was investigated using the immunoperoxidase method and the monoclonal antibody (Mab) MYC 1-9E10 in bone marrow paraffin sections. 180 cases of multiple myeloma (MM) were studied. C-myc expression was found to correlate well with the grade of malignancy, type of myeloma and tumor cell burden (p < 0.001). A relationship was also observed between C-myc p62 and IgA-secreting myelomas. It was found that intermediate grade myelomas are heterogeneous as far as C-myc expression is concerned. Our findings strongly suggest that C-myc might be involved in myelomutagenesis. The evaluation of its expression in MM may be helpful in determining the grade of malignancy and possibly the biological behaviour of this tumor.