Prolonged survival in Richter syndrome with subsequent reemergence of CLL: a case report including serial cell-surface phenotypic analysis

The clonal origin of two cell populations in Richter's syndrome

A case of Richter's syndrome was studied by morphology, immunohistochemistry, flow cytometry, and immunoglobulin gene rearrangement. Flow cytometric study clearly demonstrated two monoclonal populations. The use of double staining with CD 5/CD 19 antibodies accompanied by two-color flow cytometric analysis clearly defined the chronic lymphocytic leukemia population and separated it from the lymphoma population. Immunoglobulin heavy-chain gene analysis of blood and lymph node specimens revealed nonidentical as well as identical nongermline bands in these two populations. However, light-chain gene analysis demonstrated that both populations shared a common clonal origin. This result underscores the unreliability of using heavy chain genotype alone to identify clonal origin. Since post-rearrangement deletion, point mutation, and heavy chain switching occur in heavy chain genes, but are seldom seen in light chain genes, it is important to analyze both heavy and light chain genes to conclusively determine clonal origin.

Centroblastic lymphoma of the thyroid supervening long-lasting chronic lymphocytic leukemia (B-CLL) demonstration of biclonality by immunohistochemical and gene rearrangement analysis

A 67-year-old woman suffering since 5 years from a so far nontreated B-CLL underwent hemithyroidectomy for a rapidly enlarging tumor. Histologically, the coincidence of a centroblastic lymphoma and thyroidal infiltration by the CLL was diagnosed. Immunohistology revealed typical immunoprofils for both, B-CLL and centroblastic lymphoma on the background of B cell differentiation antigens. The bitypical immunoglobulin light chain expression--lambda on the B-CLL cells and kappa on the centroblasts--suggested biclonality. This was confirmed by gene rearrangement analysis of peripheral leukemia cells and tumor tissue. Thus, the final diagnosis of a primary thyroidal lymphoma of the centroblastic type (stage IE) arising independently from a preexisting B-CLL was achieved. Consequently, the patient received local radiotherapy. In our opinion, the designation "Richter's Syndrome", readily applied in the literature, is inappropriate for this tumor constellation.

Relapsing large cell immunoblastic lymphoma complicating well-differentiated lymphocytic lymphoma: a report of two cases showing prolonged survival with therapy

Two patients presented with co-existing large cell immunoblastic and well-differentiated lymphocytic lymphomas. Prolonged remissions from the large cell lymphomas were achieved following intensive combination chemotherapy but both patients suffered relapses after many years. Previous reports have grouped such patients with those developing classical Richter's syndrome implying a uniformly poor prognosis. This report suggests that this is not the case. It was not possible with immunohistochemical stains to prove or disprove that these tumours had the same stem cell origins.