The median age at diagnosis of BPLL
is 69 years, and the condition has a similar distribution pattern among male and female patients, who typically present with B symptoms, marked lymphocytosis, massive splenomegaly, and minimal lymphadenopathy .
Cytogenetic abnormalities in T-cell PLL include inv, trisomy 8q, 6q- and trisomy 7q. The inversion involving 14q11 breakpoint, where the gene coding for the alpha chains of the alpha-beta TCR is located, and at 14q32, which is located in the proximity of the immunoglobulin heavy (IgH) chain gene, appears characteristic but not entirely unique to patients with T-PLL, and only rarely is observed in other mature T-cell leukemias. It is apparent, therefore, that the different karyotypic patterns of these phenotypic variants of PLL reflect fundamental differences and are useful in distinguishing BPLL