CD20 negative primary diffuse large B cell lymphoma of breast: Role of Pax-5

• Published in: Journal of cancer research and therapeutics 2015-07, Vol.11 (3), p.658
• Main Authors: Shukla, Saumya, Awasthi, Namrata Punit, Singh, Pradyumn, Husain, Nuzhat
• Format: Article
• Language: English
• Subjects: Adult; Antigens, CD20 - metabolism; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Biomarkers, Tumor - metabolism; Breast Neoplasms - diagnosis; Breast Neoplasms - drug therapy; Breast Neoplasms - metabolism; Care and treatment; Case studies; Diagnosis; Female; Humans; Lymphoma, Large B-Cell, Diffuse - diagnosis; Lymphoma, Large B-Cell, Diffuse - drug therapy; Lymphoma, Large B-Cell, Diffuse - metabolism; Non-Hodgkin's lymphomas; Patient outcomes; PAX5 Transcription Factor - metabolism; Risk factors
• ISSN: 0973-1482; 1998-4138
• DOI: 10.4103/0973-1482.140792

Pax-5 is a B cell marker, the expression of which is detectable in as early as the pro B stage, and subsequently, in all further stages of B cell development except the plasma cells. Malignant lymphomas of breast are uncommon and occur as either primary or secondary lesions. Primary lymphoma is a rare disorder of breast and constitutes less than 0.6% of all breast malignancies and 2.2% of extranodal lymphomas. We report an unusual case of CD20 negative Pax-5 positive primary diffuse large B cell lymphoma (DLBCL) of breast. The case highlights the diagnostic challenge posed by extranodal CD20 negative DLBCL. Pax-5 immunohistochemistry has diagnostic benefit as a B-cell marker in the work-up of undifferentiated malignant neoplasms. Although it is available for nearly a decade now, it is not widely used. Pax-5 is a valuable addition to the armamentarium of markers currently available for lymphoma subtyping.