An Assessment of the Usefulness of Immunohistochemical Stains in the Diagnosis of Hairy Cell Leukemia

Dept of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA.
American Journal of Clinical Pathology (Impact Factor: 2.88). 09/2011; 136(3):390-9. DOI: 10.1309/AJCP5GE1PSBMBZTW
Source: PubMed

ABSTRACT Annexin-1 and T-bet are recently described immunohistochemical stains that reportedly assist in the diagnosis of hairy cell leukemia (HCL). Our objective was to assess the sensitivity and specificity of a panel of immunohistochemical stains in distinguishing HCL from other B-cell neoplasms, particularly splenic and extranodal marginal zone lymphomas (SMZL and ENMZL, respectively). The study included 234 bone marrow biopsy specimens: 101 HCL, 13 SMZL, and 10 ENMZL cases were assessed with CD20, tartrate-resistant acid phosphatase (TRAP), DBA.44, a-1, T-bet, and cyclin D1, and 110 control cases were assessed with annexin-1 and T-bet. Our study showed that annexin-1 is a specific and sensitive marker for HCL; however, interpretation is limited by positivity within myeloid precursors. T-bet, DBA.44, and TRAP immunohistochemical stains lack sufficient sensitivity and specificity to differentiate HCL from either form of marginal zone lymphoma. However, our data suggest that the addition cyclin D1 to the immunostaining panel will increase the sensitivity and specificity of HCL diagnosis.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Hairy cell leukemia (HCL) is usually diagnosed by morphology and flow cytometry studies. However, it is challenging sometimes to distinguish HCL from its mimics. Recently, the BRAF V600E mutation has been described as a disease-defining molecular marker for HCL which is present in nearly all cases of HCL but virtually absent in mimics of HCL. In this study, we investigated the possibility of using immunohistochemical detection of the BRAF V600E mutant protein to differentiate HCL from its mimics. A total of twenty-eight FFPE tissue specimens were studied, including HCL (n=12), HCL variant (HCL-v, n=3), splenic marginal zone lymphoma (SMZL, n=6), and other marginal zone lymphomas (MZL, n=7). Immunohistochemical studies were performed using a mouse monoclonal antibody (clone VE1, Spring Bioscience, CA) specific for BRAF V600E mutation. Molecularly confirmed BRAF V600E mutation positive and negative cases were used as the positive and negative controls respectively. All 12 cases of HCL showed cytoplasmic BRAF V600E protein expression in leukemia cells by immunohistochemical study regardless of tumor burden, whereas all cases of HCL mimics including HCL-v, SMZL, and MZL were negative for BRAF V600E protein. Using this BRAF V600E mutation specific antibody, this immunohistochemical study has 100% sensitivity and 100% specificity for the diagnosis of HCL in our cohort. In conclusion, immunohistochemical detection of the BRAF V600E mutant protein is highly sensitive and specific for the diagnosis of HCL. Compared to PCR or sequencing-based methodologies, immunohistochemistry is a relatively rapid and inexpensive alternative for the differential diagnosis between HCL and its mimics.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hairy cell leukemia (HCL) is an uncommon B cell lymphoproliferation characterized by a unique immunophenotype. Due to low number of circulating neoplastic cells and 'dry tap' aspiration, the diagnosis is often based on BM trephine biopsy. We have performed a consecutive immunohistochemical analysis to evaluate diagnostic usefulness of various HCL markers (CD11c, CD25, CD68, CD103, CD123, CD200, annexin A1, cyclin D1, DBA.44, HBME-1, phospho-ERK1/2, TRAP, and T-bet) currently available against fixation resistant epitopes. We analyzed tissue microarrays consisting of samples gained from 73 small B-cell lymphoma cases, including hairy cell leukemia (HCL) (n = 32), HCL variant (HCL-v) (n = 4), B-cell chronic lymphocytic leukemia (B-CLL) (n = 11), lymphoplasmacytic lymphoma (LPL) (n = 3), mantle cell lymphoma (MCL) (n = 10), splenic diffuse red pulp small B cell lymphoma (SDRPL) (n = 2), splenic B cell marginal zone lymphoma (SMZL) (n = 8), and splenic B cell lymphoma/leukemia, unclassifiable (SBCL) (n = 3) cases. The HCL cases were 100 % positive for all but 2 (DBA.44 and CD123) of these markers. Annexin A1 showed 100 % specificity and accuracy, which was followed by CD123, pERK, CD103, HBME-1, CD11c, CD25, CD68, cyclin D1, CD200, T-bet, DBA.44, and TRAP, in decreasing order. In conclusion, our results reassured the high specificity of annexin A1 and pERK, as well as the diagnostic value of standard HCL markers of CD11c, CD25, CD103, and CD123 also in paraffin-embedded BM samples. Additional markers, including HBME-1, cyclin D1, CD200, and T-bet also represent valuable tools in the differential diagnosis of HCL and its mimics.
    Pathology & Oncology Research 06/2014; 21(1). DOI:10.1007/s12253-014-9807-5 · 1.81 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The BRAFV600E mutation is a highly sensitive and specific marker for the diagnosis of hairy cell leukaemia (HCL) and a potential therapeutic target. We assessed the performance of high resolution melting (HRM), allele-specific priming (ASP) and Sanger sequencing (SS) for BRAFV600E detection in 17 unenriched samples from 15 HCL patients: blood (n = 7), marrow aspirate (n = 3), ethylenediaminetetraacetic acid (EDTA)-decalcified trephine biopsy (n = 2), formic acid (FA)-decalcified trephine biopsy (n = 5). Our results showed that for blood and marrow aspirate samples, both HRM and ASP had a very high analytical sensitivity (1%) in clinical specimens and excellent diagnostic sensitivity (100%) and specificity (100%) in analysable samples. Sanger sequencing had a lower analytical sensitivity (4%), resulting in false-negative analysis in samples with a low tumour cell percentage. High resolution melting was technically the simplest and had the shortest turn-around time (2 hours). Analysis of decalcified trephine biopsies was more difficult because of suboptimal DNA preservation. Although Sanger sequencing was least demanding on sample DNA quality for a successful analysis, none of the three techniques showed satisfactory diagnostic performance on trephine biopsies. Therefore, careful selection of a suitable sample type and testing platform is important to optimise the detection of this important mutation in HCL.
    Pathology 08/2014; 46(6). DOI:10.1097/PAT.0000000000000151 · 2.62 Impact Factor