[1406] Atypical Chronic Lymphocytic Leukemia: Morphologic, Immunophenotypic, Cytogenetic and Oligo SNP Array Comparative Genomic Hybridization Profile

Tarek Jazaerly, Salman Ayub, Leopoldo Eisenberg, Anwar Mohamed, Salah Ebrahim, Ali Gabali, Ayad Al-Katib, Margarita Palutke. Wayne State University/Detroit Medical Center/Barbara Ann Karmanos Cancer Institute, Detroit, MI

Background: Chronic lymphocytic leukemia (CLL) is the most common leukemia in Western Europe and United States. It is, as a rule, CD5 positive. CD5 negative CLL is encountered infrequently and has several features which differ from CD5 positive CLL. The aim of this study is to compare multiple parameters of CD5 positive and CD5 negative CLL.
Design: Thirty consecutive cases with the diagnosis of atypical CLL were selected from our central referral hematology laboratory. Clinical data, morphological and immunophenotypic findings, and cytogenetic features including conventional chromosome analysis and fluorescence in situ hybridization (FISH) were studied. Additionally, combined oligonucleotide-single nucleotide polymorphism (Oligo-SNP)-comparative genomic hybridization (CGH) was performed on 8 cases of atypical CLL and 8 cases of typical CLL. Electron microscopy (EM) was performed on 6 cases in order to identify the cytoplasmic granules commonly seen in this leukemia.
Results: The male to female ratio was: 1:1. The age ranged from 37 to 98 years, median: 67. The peripheral blood was the presenting site of involvement in all cases and bone marrow was available and involved in 10 cases. Lymphadenopathy was present in 4 cases and splenomegaly in 5. Generally, the neoplastic cells were medium-sized with moderate to abundant pale cytoplasm and visible nucleoli. Smudge cells were lacking. In some cases, the neoplastic cells showed cytoplasmic vacuoles and cytoplasmic granules which by EM appeared to be crystalline structures of immunoglobulins. Flow cytometry in the majority of the cases showed bright CD20, bright s-Ig, CD23+, FMC7+, CD22+, CD11c+, CD5-, CD25- and CD103-. Del 17p/P53 was detected in 11 cases and trisomy 12 in 6 cases. Oligo-SNP array in the 8 atypical cases revealed abnormality in chromosome 5q13.2 in 5 cases, including duplication in 4 cases and deletion in one. On the other hand, del 14q32.33 was seen in 6 typical CLL cases, del 13q14.3 in 5 cases and trisomy 12 in three cases. 5q abnormality was not detected in typical CLL cases.
Conclusions: The 5q13.2 chromosomal abnormality may represent a unique feature in CD5 negative atypical CLL and, thus, warrants further studies to determine its possible impact clinically.
Category: Hematopathology

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 214, Monday Morning


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