Chronic lymphocytic leukemia/small lymphocytic lymphoma with cyclin D1 positive proliferation centers do not have CCND1 translocations or gains and lack SOX11 expression.
Cyclin D1 expression, usually absent in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), has been described in the proliferation centers (PC) of some CLL/SLL. The prevalence of this finding is uncertain, as is the explanation for its occurrence and whether these cases have any other unique features. Cyclin D1 immunohistochemical staining was therefore investigated in 57 extramedullary CLL/SLL biopsies. In 6 cases, cyclin D1 immunofluorescence followed by CCND1 fluorescence in situ hybridization (FISH) and PC targeted analysis was performed using a Bioview Duet system. Excluding the prospectively selected cases that had the targeted FISH studies, cyclin D1+ PC were identified in 20% of cases. The cyclin D1+ CLL did not appear pathologically or phenotypically distinctive, though 46% had an interfollicular growth pattern. The cyclin D1+ PCs were SOX11- and lacked CCND1 translocations and gains in 5 of 5 informative cases. The recognition of cyclin D1 expression in PC of a significant minority of CLL/SLL can be a diagnostic aid and should not lead to the diagnosis of focal mantle cell lymphoma.
Division of Hematopathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
Joel F
JF
Gradowski
Rachel L
RL
Sargent
Fiona E
FE
Craig
Kathleen
K
Cieply
Kim
K
Fuhrer
Carol
C
Sherer
Steven H
SH
Swerdlow
D000368:Aged; D000369:Aged, 80 and over; D019938:Cyclin D1 / Q000235:genetics* / Q000378:metabolism; D005260:Female; D018858:Germinal Center / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055751:SOXC Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014178:Translocation, Genetic
C097473:SOX11 protein, human; D055751:SOXC Transcription Factors; D019938:Cyclin D1