Case Report: Chronic Lymphocytic Leukemia With a Rare Translocation t(14;19)(q32;q13) Involving IGH/BCL3 Rearrangements: Report of Three Chinese Cases and Literature Review

[Clinical characteristics of 11 patients with chronic lymphocytic leukemia with t (14;19) (q32;q13)]

Objective: To analyze the clinicopathological characteristics of 11 cases of chronic lymphocytic leukemia (CLL) with t (14;19) (q32;q13) . Methods: The case data of 11 patients with CLL with t (14;19) (q32;q13) in the chromosome karyotype analysis results of the Blood Diseases Hospital, Chinese Academy of Medical Sciences from January 1, 2018, to July 30, 2022, were retrospectively analyzed. Results: In all 11 patients, t (14;19) (q32;q13) involved IGH::BCL3 gene rearrangement, and most of them were accompanied by +12 or complex karyotype. An immunophenotypic score of 4-5 was found in 7 patients and 3 in 4 cases. We demonstrated that CLLs with t (14;19) (q32;q13) had a mutational pattern with recurrent mutations in NOTCH1 (3/7), FBXW7 (3/7), and KMT2D (2/7). The very-high-risk, high-risk, intermediate-risk, and low-risk groups consisted of 1, 1, 6, and 3 cases, respectively. Two patients died, 8 survived, and 2 were lost in follow-up. Four patients had disease progression or relapse during treatment. The median time to the first therapy was 1 month. Conclusion: t (14;19) (q32;q13), involving IGH::BCL3 gene rearrangement, is a rare recurrent cytogenetic abnormality in CLL, which is associated with a poor prognosis.

IGH Translocations in Chinese Patients With Chronic Lymphocytic Leukemia: Clinicopathologic Characteristics and Genetic Profile

Immunoglobulin heavy chain translocations (IGH-t) have occasionally been reported in Chinese patients with chronic lymphocytic leukemia (CLL). The objective of the present study was to identify the clinicopathologic features of patients with IGH-t CLL and compare them with those of patients with non-IGH-t CLL. We performed fluorescence in situ hybridization (FISH) based on a routine CLL prognostic FISH panel using IGH, IGH-BCL2, BCL3, IGH-CMYC, and BCL6 FISH probes. Furthermore, we retrospectively evaluated the clinical features of 138 newly diagnosed CLL patients via chromosome banding analysis (CBA), FISH, and targeted next-generation sequencing. IGH-t was identified in 25 patients (18.1%). Patients with IGH-t CLL had lower flow scores than those with non-IGH-t CLL. The most frequent translocation was t(14;18) (10 patients), followed by t(14;19) (3 patients), and t(2;14)(p13;q32), t(7;14)(q21.2;q12), t(9;14)(p13;q32) (3 patients). The remaining nine patients included three with abnormal karyotypes without translocation involving 14q32, four with a normal karyotype, and two who failed CBA. The most frequently concomitant FISH-detected aberrations were 13q deletion, followed by +12 and TP53 deletion, while one case involved ATM deletion. Complex karyotypes were detected in five patients with IGH-t CLL, in whom all partner genes were non-BCL2. Available mutational information indicated that KMT2D mutation was the most frequent mutation among tested 70 patients, while TP53 mutation was the most frequent mutation in the IGH-t group. Moreover, the IGH-t group had higher FBXW7 (P=0.014) and ATM (P=0.004) mutations than the non-IGH-t group, and this difference was statistically significant. Our study demonstrates that IGH-t is not uncommon among Chinese CLL patients, and that its partner genes are multiple. The gene mutational profile of the IGH-t group was distinct from that of the non-IGH-t group, and the concomitant chromosomal abnormalities within the IGH-t CLL group differed. Thus, identification of IGH-t and its partner genes in CLL patients may help further refine risk stratification and strengthen the accurate management in CLL patients.

[Chronic lymphocytic leukemia with t (14;18) (q32;q21) : report of eight cases and a literature review]

Objective: The study aimed to analyze the clinical features and prognosis of chronic lymphocytic leukemia (CLL) with t (14;18) (q32;q21) and conduct a literature review. Methods: The clinical data of 8 patients with CLL carrying t (14;18) (q32;q21) seen in Jiangsu Province Hospital from November 2009 to November 2019 were collected and analyzed. Results: Among the 8 cases, 7 were male and 1 was female. The median age at diagnosis was 70 years old. The immunophenotype score was 5 in 3 patients. 4 patients were scored 4 and the remaining one scored 3. The bone marrow histopathology showed the typical manifestation of CLL. Karyotype analysis showed that all the cases carried t (14;18) (q32;q21) in the stemline. The t (14;18) (q32;q21) showed as the sole abnormality in 3 cases, with +12 in 4, and with 13q- in 1 case. 13q- was found in another 3 patients by FISH. Immunoglobulin heavy chain gene (IGHV) mutation status was detected in 6 cases and all of them were mutated. None of them used IGHV3-21. Only 1 case harbored TP53 mutation and no TP53, SF3B1, NOTCH1, or MYD88 mutations were found in the remaining cases who underwent the relevant tests. At a median follow-up of 30.9 months, 1 case died. The remaining 7 cases survived and 3 of them have not reached the treatment indication. 4 patients who received chemotherapy or immunotherapy were stable. Conclusions: The t (14;18) (q32;q21) is rare in CLL and often accompanied by +12 and mutated IGHV. CLL with t (14; 18) (q32; q21) tends to have a good prognosis.