Oct2 and Bob1 are sensitive and specific markers in lineage determination of B cell lymphomas with no expression of conventional B cell markers.

Abstract

AIMS:

Rare cases of B cell lymphomas do not express conventional B cell markers (CD20, CD79a and PAX5), and these types of lymphomas include anaplastic lymphoma kinase (ALK)-positive large B cell lymphoma, plasmablastic lymphoma, primary effusion lymphoma and the solid variant of primary effusion lymphoma, extracavitary human herpesvirus 8 (HHV8)-positive large B cell lymphoma. Establishing accurate diagnoses of these B cell lymphomas can be challenging, and often requires a large panel of immunohistochemical stains, molecular assays and cytogenetic studies. B cell-specific transcription factors, Oct2 and Bob1, have been shown to be expressed consistently in most, if not all, B cell lymphomas, and therefore we investigated the utility of Oct2 and Bob1 immunohistochemistry in lineage determination of the aforementioned B cell lymphomas.

METHODS AND RESULTS:

We selected 34 cases of previously diagnosed B cell lymphomas with no or weak expression of CD20, CD79a and PAX5. Oct2 and Bob1 were positive in 74% (25 of 34) and 85% (29 of 34) of the cases, respectively. When we combined the results of these two immunostains, 94% (32 of 34) cases expressed at least one of these two markers. We also included 51 control cases of non-B cell neoplasms, and none of them expressed either Oct2 or Bob1.

CONCLUSIONS:

Oct2 and Bob1 are very reliable in determining B cell lineage in the absence of expression of other pan-B cell markers, and it should provide great diagnostic benefit to include them both in a panel of immunohistochemistry to assess undifferentiated malignant neoplasms.

• Authors: Liqun Yin, Jie Xu, Min Li, Vishnu Reddy, Quan Zhou, Huanxin Liu, Peiguo Chu, Qianyun Zhang, Qin Huang, Zifen Gao, Xiayuan Liang, Huan-You Wang, Zenggang Pan
• Journal: Histopathology (Histopathology) Vol. 69 Issue 5 Pg. 775-783 (Nov 2016) ISSN: 1365-2559 [Electronic] England
• PMID: 27319306 (Publication Type: Journal Article)
• Copyright: © 2016 John Wiley & Sons Ltd.

Chemical References

• Biomarkers, Tumor
• Organic Cation Transport Proteins
• Organic Cation Transporter 2
• POU2AF1 protein, human
• SLC22A2 protein, human
• Trans-Activators

Topics

• Biomarkers, Tumor (analysis)
• Cell Lineage
• Humans
• Lymphoma, Large B-Cell, Diffuse (diagnosis)
• Organic Cation Transport Proteins (analysis, biosynthesis)
• Organic Cation Transporter 2
• Sensitivity and Specificity
• Trans-Activators (analysis, biosynthesis)