Atypical chronic lymphocytic leukaemia with t(11;14)(q13;q32): karyotype evolution and prolymphocytic transformation

In order to define better the cytological and clinical features of atypical B-cell chronic lymphocytic leukaemia (B-CLL) with t(11:14)(q13;q32), sequential morphologic immunological and cytogenetic studies were performed in seven patients belonging to a series of 72 consecutive cases presenting with a diagnosis of CLL or atypical CLL according to the FAB criteria. Cytologic diagnosis in these seven patients with t(11;14) was typical CLL in two cases presenting with 40% cells in 5/6 cases. Chromosome changes in addition to t(11;14) were seen in five cases; in two cases unbalanced translocations involving the 3q21 chromosome region, resulting in partial trisomy for the long arm of chromosome 3, were detected early in the course of the disease. Karyotype evolution that was associated with disease progression occurred in 3/6 assessable patients. Comparison of these findings with similar data from 65 B-CLL patients without t(11:14) showed that atypical morphology, switch of FAB diagnosis during the course of the disease, and karyotype evolution were more frequently seen in cases with t(11;14) (5/7 v 15/65 cases, P = 0.015, 7/7 v 7/65 cases, P < 0.0001, and 3/6 v 5/45 assessable cases, P = 0.04, respectively). The frequency of positivity for CD23 and bright SIg staining differed significantly in the two groups. It is concluded that t(11;14) identifies a cytologically atypical subset of B-CLL, characterized by frequent cytologic and cytogenetic evolution and by a distinct immunological profile, sharing some biological features with mantle cell lymphoma