Article

PAX-5: a valuable immunohistochemical marker in the differential diagnosis of lymphoid neoplasms.

Department of Pathology & Laboratory Medicine, Medical University of South Carolina
Clinical Medicine &amp Research 07/2010; 8(2):84-8. DOI: 10.3121/cmr.2010.891
Source: PubMed

ABSTRACT Undifferentiated tumors and hematolymphoid neoplasms can be diagnostically challenging due to potential overlap of morphologic features and variant antigen expression. PAX-5, a transcription factor expressed throughout B-cell maturation, is detected in most B-cell neoplasms including those that lack expression of mature B-cell markers, such as classical Hodgkin lymphoma (cHL), B-lymphoblastic leukemia and B-cell lymphomas following rituximab therapy. The lack of PAX-5 expression in most CD30-positive non-hematopoietic malignancies (embryonal carcinoma and seminoma) and T-cell lymphomas, such as anaplastic large cell lymphoma (ALCL), suggests that the absence of PAX-5 may be used to confirm non-B-cell lineage. The goal of this study was to retrospectively assess PAX-5 immunoreactivity in diagnostic samples of hematolymphoid and other non-hematopoietic malignancies.
Diagnostic lymph node, decalcified core bone marrow biopsies and tissue sections from 111 archived paraffin-embedded tissue blocks and a tissue lymphoma microarray were immunostained using a monoclonal antibody to PAX-5. The corresponding hematoxylin and eosin stained tissue sections and additional immunostains were simultaneously evaluated. PAX-5 immunoreactivity in neoplastic cells was scored as positive or negative. This study was exempted by the Institutional Review Board for Human Research.
Nuclear PAX-5 immunoreactivity was detected in 88% (36/41) of Hodgkin lymphoma, all cases of diffuse large B-cell lymphoma (n=72), small B-cell lymphomas (n=5), B-lymphoblastic leukemia/lymphoma and mixed phenotype acute leukemia with B-cell lineage (n=5). PAX-5 was not detected in ALCL (n=22), T-cell lymphoblastic leukemia/lymphoma, mixed phenotype acute leukemia with T-cell lineage (n=5), acute myeloid leukemia (n=4), carcinoid tumors with typical morphology (n=5), melanoma (n=3), and undifferentiated/metastatic tumors (n=8). Non-neoplastic bone marrow sections showed scattered nuclear staining in small B-cell lymphocytes/hematogones. The detection of PAX-5 immunoreactivity resulted in the reclassification of two cases of ALCL to cHL.
Overall, our results demonstrate that including PAX-5 in a panel with other immunomarkers helps establish B-cell lineage and increases diagnostic yield.

0 Bookmarks
 · 
91 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Uncommon tumors in the uterus present diagnostic challenges. In some cases, the tumor subtype is usually seen outside of the gynecologic tract and the possibility of a uterine primary is not considered. In other cases, histologic overlap with more common uterine tumors leads to potential misdiagnosis. Finally, metastatic carcinoma may the uterus and cervix. Rarely, symptoms related to the uterine metastasis may precede diagnosis of an extra uterine primary. Without the proper clinical context, the possibility of a missed diagnosis is increased. One must first be aware of these possibilities, but immunoperoxidase studies are often necessary to confirm the diagnosis. In this review, unusual and metastatic tumors involving the uterine corpus and cervix and immunoperoxidase studies used to diagnosis such tumors are discussed.
    Seminars in Diagnostic Pathology 05/2014; · 1.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cancer biomarkers have provided great opportunities for improving the management of cancer patients by enhancing the efficiency of early detection, diagnosis, and efficacy of treatment. Every cell type has a unique molecular signature, referred to as biomarkers, which are identifiable characteristics such as levels or activities of a myriad of genes, proteins, or other molecular features. Biomarkers can facilitate the molecular definition of cancer, provide information about the course of cancer, and predict response to chemotherapy. They offer the hope of early detection as well as tracking disease progression and recurrence. Current progress in the characterization of molecular genetics of HIV-associated cancers may form the basis for improved patient stratification and future targeted or individualized therapies. Biomarker use for cancer staging and personalization of therapy at the time of diagnosis could improve patient care. This review focuses on the relevance of biomarkers in the most common HIV-associated malignancies, namely, Kaposi sarcoma, non-Hodgkin's lymphoma, and invasive cervical cancer.
    Biomarkers in cancer. 01/2014; 6:11-20.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A 7-month-old castrated male French Bull dog was presented with vomiting, lethargy, anorexia and weight loss of 2 weeks duration. The patient's history and clinical manifestations of suspected hepatopathy were subjected to ultrasonography, radiography, biochemical investigations and cytology of hepatic lesion. The cytologic impression was hepatic lymphoma, which was later confirmed by histopathology. The neoplastic cells were strongly diffusely immunoreactive for PAX5, but not immunoreactive for CD3, and B lymphocyte specific clonal proliferation was detected using by assay of antigen receptor rearrangement. Large numbers of immunoreactive mature non-neoplastic lymphocytes were admixed with the neoplastic cell population. Therefore, the immunohistochemical results were definitively consistent with a T-cell rich B-cell lymphoma (TCRBCL). This is the first description of a hepatic TCRBCL in a juvenile dog showing a poor response to aggressive chemotherapy.
    Journal of Veterinary Medical Science 10/2014; · 0.88 Impact Factor

Preview

Download
0 Downloads
Available from