Interphase fluorescence in situ hybridization with an IGH probe is important in the evaluation of patients with a clinical diagnosis of chronic lymphocytic leukaemia

Abstract

Summary Translocations involving IGH are common in some lymphoid malignancies but are believed to be rare in chronic lymphocytic leukaemia (CLL). To study the clinical utility of fluorescence in situ hybridization (FISH) for IGH translocations, we reviewed 1032 patients with a presumptive diagnosis of CLL. Seventy‐six (7%) patients had IGH translocations. Pathology and clinical data were available for the 24 patients evaluated at the Mayo Clinic. Ten (42%) patients had IGH/cyclin D1 fusion and were diagnosed with mantle cell lymphoma (MCL). The immunophenotype was typical of MCL in three of these patients and atypical for MCL in seven patients. One patient had biclonal disease with typical MCL and CLL with IGH/BCL‐2. Eleven (46%) patients had IGH/BCL‐2 fusion including the patient with biclonal disease. Two of these patients had leukaemic phase follicular lymphoma and nine patients had CLL. The median progression‐free survival of patients with CLL and IGH/BCL‐2 translocation was 20·6 months. The two patients with IGH/BCL‐3 fusion (one of these also had IGH/BCL‐11a) had rapid disease progression. The IGH partner gene was not identified in two patients. We conclude that use of an IGH probe in FISH analysis of monoclonal B‐cell lymphocytosis improves diagnostic precision and could have prognostic value in patients with CLL.

MYC translocation in chronic lymphocytic leukaemia is associated with increased prolymphocytes and a poor prognosis

“…Similar to the patients we report, this patient had classic cytology and immunophenotype, and splenomegaly (Reddy et al, 2006). In other reports with smaller cohorts of CLL patients, either none or rare cases with MYC translocation have been identified by either conventional cytogenetic analysis or FISH studies (Rechavi et al, 1989;Raghoebier et al, 1991;Dohner et al, 2000;Nowakowski et al, 2005;Nelson et al, 2007).…”

Array-based karyotyping in chronic lymphocytic leukemia (CLL) detects new unbalanced abnormalities that escape conventional cytogenetics and CLL FISH panel

“…16 ). Translocations and deletions of 14q32 involving the IGH gene were found in up to 5% of CLL patients [17][18][19] . Other chromosomal abnormalities involving regions of 3q, 8q, 9p and other regions are less frequent in CLL.…”

Translocation t(14;18) is not associated with inferior outcome in chronic lymphocytic leukemia

“…This contrasts with earlier studies reporting a TFS of only 2 months in patients with 14q32/IGH translocations (n ¼ 18) 6 and a progression-free survival (PFS) of 20.6 months in patients with IGH/BCL2 translocations (n ¼ 8). 5 However, another study showed different PFS and time to treatment (TTT) according to the partner gene. Indeed, translocations involving BCL3 were correlated with a worse prognosis than those involving BCL2 with a median TTT of 1.5 and 3.6 years, respectively (P ¼ 0.017).…”

“…[2][3][4] Their significance remains poorly understood. 5 In published series, 4,6 part of the cases have unknown partner genes. Recurrent partner genes include BCL2, BCL3, BCL11A and CMYC.…”