4. Hrvatski kongres kliniËke citologije 4th Croatian Congress ... - Penta

Clinical Cytology - Plenary and Invited Lectures
SMALL LYMPHOCYTIC LYMPHOMAS - PITFALLS IN METHODS AND INTERPRETATION
Dominis M
Dpt.of Pathology & Cytology, Clinical Hospital “Merkur”, Zagreb, Croatia
Small B-cell lymphomas/leukemias are derived from the mature B-cells. In term of
clinical, morphological and molecular aspects they represent a hetrogenous group of
diseases. Although overlap is present, clinically distinct entities exist with characteristic
presentation, response to therapy and/or prognosis.
Despite well defined morphological, immunohistochemical and molecular characteristics,
atypical case may exist in single entity. Overlap of morphological and immunohistochemical
features between various entities of B small cell lymphomas can induce
considerable diagnostic problems. It is of great importance to distinguish between such
entities whenever is possible because of contrast of some poor prognosis cases and
long survival of others.
201 patients with predominantly small B-lymphocytic lymphoma were reevaluated. 100
were diagnosed as follicular cell lymphoma (FCC), 45 as mantle cell lymphoma and 56
as small lymphocytic lymphoma (SLL). Adverse findings were: in FCC group BCL2 was
positive; 11 cases without any changes of BCL2 gene, however in another 4 cases BCL2
was negative and gene was either in translocation or amplification. BCL6 was positive in
70 cases but the BCL6 gene showed translocation only in 8 and amplification in 7 cases,
respectively. Translocation of BCL2 and BCL6 genes was found in 8 and amplification
in 7 patients. 45 mantle cell lymphomas were all CD20 and BCL2 positive and CD23 and
CD43 negative; 32 out of 45 were CD5 positive, 8 were +/- and 5 were CD5 negative. In 43
patients t(11;14) was found, and in one case BCL1 gene amplification. t(14;18) was found
in one case, amplification of BCL2 gene in 7 cases. Two patients with blastiod variant of
mantle cell lymphoma were CD5+, BCL2 as well as BCL1 were in one case positive and
in another negative. Neither t(11;14) or t(14;18) were found. In so-called SLL group of 56
patients, who were all CD19 and BCL2 positive, CD5, CD23 and CD43 were positive in 51
patients. t(11;14) was found in 5 patients, 4 who were CD5 and CD23 positive and one
who was CD5 and CD23 negative. Other abnormalities, i.e. 3-5 copies of BCL1 gene were
found in 3 CD5, CD23 positive patients. Pitfalls in methods and interpretation will be discussed
and are still matter of debate.
mara.dominis@zg.t-com.hr
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4 th Croatian Congress of Clinical Cytology / 1 st Croatian Symposium of Analytical Cytology / 2 nd Croatian Symposium of Cytotechnology