Hyperdiploidy in CLL/SLL: A Rare Cytogenetic Event Associated with Poor Prognosis

Hyperdiploidy has been described in a variety of malignancies including acute lymphoblastic leukemia and plasma cell myeloma, in which the abnormality is associated with a very good prognosis. Herein, we describe a 61-year-old female that was diagnosed with atypical chronic lymphocytic leukemia (CLL). Initial chromosome analysis of a lymph node specimen showed an abnormal karyotype described as 46-48,XX,add(3)(q12),+16,+mar[cp3]/46,XX[1]. Chromosome analysis of the bone marrow a week later showed a pseudodiploid and normal diploid clone described as: 46,X,-X,-3,-6,+7,+9,-14,-15,+16,+17,+17,+20,-22[1]/46,XX[19]. Concurrent FISH studies of peripheral blood samples using the CLL FISH panel showed nuclei with an extra copy of chromosome 13 and an extra copy of the short arm of chromosome 17. FISH for t(11;14) was negative. These results suggest the presence of an underlying complex hyperdiploid karyotype. Hyperdiploidy is a rare event in SLL/CLL and is usually associated with a poor prognosis.