Test Details: Immunohistochemical testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody. MUM-1 is a marker for post-germinal centre B cells, plasma cells, and subset of T cells and related lymphoma types in addition to Hodgkin cells. It is expressed in plasma cell neoplasms, diffuse large B-cell lymphoma. It is also expressed in Hodgkin lymphoma, CLL, marginal zone lymphoma and malignant melanoma.