Reassessment of small lymphocytic lymphoma in the era of monoclonal B-cell lymphocytosis

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BlankReassessment of small lymphocytic lymphoma in the era of monoclonal B-cell

lymphocytosis.

SE GibHaematologica, May 5, 2011son, SH Swerdlow, JA Ferry, U Surti, P Dal Cin,

NL , and RP Hasserjian

PA, USA;

Background. In the 2008 World Health Organization Classification, small

lymphocytic lymphoma is defined as a neoplasm with tissue morphology and

immunophenotype of chronic lymphocytic leukemia, but with absence of leukemia.

Minimal criteria of tissue involvement to separate small lymphocytic lymphoma

from monoclonal B-cell lymphocytosis have not been defined. Design and Methods.

We reviewed the clinicopathologic features of 36 patients with extramedullary

tissue biopsies containing chronic lymphocytic leukemia-type cells and <5x109/L

peripheral blood monoclonal B cells. Pathologic features (extent and patterns of

involvement, architectural preservation, presence of proliferation centers) as

well as cytogenetic and radiologic findings were examined in relation to

clinical outcome. Results. The biopsies were performed to evaluate

lymphadenopathy in 20 patients and for other reasons (most frequently staging of

a non-hematologic neoplasm) in 16 patients. At latest follow-up (median 23

months), 21 untreated patients had no or stable lymphadenopathy, 3 had regressed

lymphadenopathy, and 12 developed progressive lymphadenopathy and/or received

therapy for chronic lymphocytic leukemia/small lymphocytic lymphoma. Features

associated with progression/treatment included lymph nodes ?1.5 cm on imaging

studies (P=0.01) and presence of proliferation centers in the biopsied tissue

(P=0.004). Neither the size nor extent of involvement of the excised lymph node

correlated with progression/treatment. Conclusions. Our findings suggest that

biopsies containing chronic lymphocytic leukemia-type cells, but lacking

proliferation centers and with non-enlarged or only slightly enlarged lymph

nodes on imaging, represent a very indolent disease that may best be considered

a tissue equivalent of monoclonal B-cell lymphocytosis rather than overt small

lymphocytic lymphoma. We propose that such cases be designated as " tissue

involvement by chronic lymphocytic leukemia/small lymphocytic lymphoma-like

cells of uncertain significance " .

PMID: 21546505