[1357] Atypical Chronic Lymphocytic Leukemia, Predominantly CD5 Negative with Cytoplasmic Granules

Salman Ayub, Bradley Gehrs, Hayan Jaratli, Mohamed Anwar, Leopoldo Eisenberg, Ayad Al-Katib, Margarita Palutke. Wayne State University/Detroit Medical Center, Detroit, MI

Background: Chronic lymphocytic leukemia (CLL) is a heterogeneous disease. Some of the features not associated with typical CD5 + CLL have led investigators to classify them as atypical CLL.
Design: Twenty-three patients presenting with atypical features of the leukemia were selected and their immunophenotypic characteristics, genetic markers and clinical variables were studied.
Results: The patients' ages ranged from 37 to 98 years. Twelve patients were male and eleven were females.
Peripheral blood smears showed that the majority of neoplastic lymphocytes had the following features: moderate to large size, moderate to abundant cytoplasm, cytoplasmic granules and sometimes vacuoles, visible nucleoli and absence of smudge cells. A neoplastic cell from our study is shown.

Electron microscopy showed the granules to be crystalline structures associated with dilated profiles of rough endoplasmic reticulum, most likely representing immunoglobulins.

Flow cytometry results: CD5 – or weakly +, CD20 + (bright), CD22 +, CD23 +, FMC-7 +, CD11c + and mostly CD25 and CD 103 –. SIg were predominantly bright. Nineteen of them were kappa and three were lambda restricted. One was biclonal.
Splenomegaly was seen in only five cases and lymphadenopathy was present in four. Bone marrow was available in ten cases and was involved. Deletion of TP53 gene (del 17p13) was the most common cytogenetic abnormality seen in ten patients, followed by trisomy 12 in four, del 13q14 in four, del 11q23 and t(11;14) in one each.
Conclusions: Some features of this subset of CLL resemble a hemic phase of splenic marginal zone lymphoma or splenic lymphoma, unclassifiable, except that the majority of these cases had no splenomegaly and there were no cytoplasmic villous projections. Although TP53 deletion is generally considered a bad prognostic indicator, our patients with this deletion as a sole or combined abnormality had good clinical outcomes with little or no treatment.
Category: Hematopathology

Monday, March 19, 2012 1:00 PM

Poster Session II # 207, Monday Afternoon

 

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