Unexpected lambda chain expression in lymphocytic malignancy

Presence of three recurrent chromosomal reaarrangements, t(2;3)(p12;q37), del(8)(q24), and t(14;18), in an acute lymphoblastic leukemia

A complex chromosomal abnormality associating three recurrent rearrangements, t(2;3)((p12;q37), del (8)(q24) and t(14;18)(q32;q21), was detected in a patient with acute lymphoblastic leukemia of the Burkitt type. Southern blot studies showed rearrangements of the MYC, BCL2, and JH genes, thus confirming the cytogenetic data. However, no rearrangement of the LAZ3/BCL6 gene, normally localized on band 3q27, could be detected. The simultaneous presence of three recurrent rearrangements specific for lymphoid malignancies addresses the question of their timing in the malignant process and the prognostic significance of the association of such anomalies.

Combination of t(14;18) and a Burkitt's type translocation in B-cell malignancies

The combination of chromosomal translocations associated with bcl-2 rearrangement [t(14;18)] and c-myc rearrangement [t(8;14), t(8;22), or t(2;8)] has infrequently been detected in lymphoproliferative disorders. We have recently identified four cases of a B-cell malignancy exhibiting this dual translocation. In addition to t(14;18), one case had t(8;14) and three had the t(8;22). One case presented as de novo acute lymphoblastic leukemia (ALL-L2), two as de novo high grade lymphomas and the fourth evolved to a "blastic" phase from a previously documented follicular lymphoma. Immunophenotyping and molecular analysis was performed on three of the cases: all were negative for terminal deoxynucleotidyl transferase (TdT) but were CD10 positive. Two of the three cases with t(8;22) were negative for surface immunoglobulin (SIg) and positive for HLA-DR. Rearrangement of the oncogene bcl-2 was identified in a single case by polymerase chain reaction (PCR) only. Similar to cases reported in the literature, all patients had a poor clinical outcome despite aggressive therapy. Dual translocation lymphoid malignancy has a relatively characteristic morphology and the diagnosis should be considered when there is a history of an antecedent low grade lymphoma or when there is discordance between the "blastic" morphology and the immunophenotype (TdT- and/or SIg+). Confirmation requires demonstration of the characteristic translocations. Recognition of this entity has significant clinical implications that may require consideration of alternate treatment strategies.

Simultaneous occurrence of t(14;18) and t(8;22) common acute lymphoblastic leukemia

A young male patient progressed rapidly from localized abdominal lymph node enlargement to overt acute lymphoblastic leukemia. Despite aggressive treatment, he died of progressive CNS leukemia 5 months after initial presentation. At diagnosis, karyotypic analysis of an abdominal lymph node revealed the coexistence of t(14;18) (q32;q21), specific for follicular lymphoma, and t(8;22) (q24;q11), a variant Burkitt translocation. Such cases might be considered as a model for a general mechanism of tumor progression with cascade-like involvement of oncogenes.

Simultaneous presence of translocations t(14;18) and t(2;8) in a case of chronic lymphocytic leukemia

We report a patient with classical chronic lymphocytic leukemia of IgM kappa phenotype and a stable clinical course, in which repeated chromosome analyses of blood lymphocytes revealed the coexistence of t(14;18), a marker often associated with follicular low grade lymphocytic lymphomas, and t(2;8), a variant of the t(8;14) typically seen in Burkitt's lymphoma. Both these translocations involve immunoglobulin gene regions, the t(2;8) being almost always found in patients with kappa light chain restriction. However, in an EBV-immortalized cell line of this patient, most karyotypes contained t(14;18) alone, without the t(2;8). This suggests that t(14;18) was the primary cytogenetic event, and that t(2;8) evolved subsequently. As a secondary cytogenetic event, the t(2;8) may not share the grave clinical consequences of a primary t(2;8) as seen in Burkitt's lymphoma and related disorders.