Cerebriform variant type of T cell prolymphocytic leukemia with complex karyotype including an additional segment at 1p36.1.

We describe two patients with T cell prolymphocytic leukemia (T-PLL) who exhibited the same complex karyotype, including an additional segment at 1p36.1. One presented with secondary progression following an initial stable clinical course, and the other with typically progressive disease. Features of the cerebriform variant were identified in the peripheral blood of both patients. Aggressive symptoms, such as lymphocytosis, lymphadenopathy, pleural effusion, cutaneous involvement and hepatosplenomegaly, developed during the progressive phases. Levels of serum soluble interleukin 2 receptor increased when symptoms worsened. These patients did not have the karyotypic 14q11 abnormality and trisomy 8q that are features of non-Japanese patients. The prognoses of these patients were poor; one survived for 2 months and the other survived for 10 months after progression. A chromosomal abnormality may occur in other types of aggressive T-PLL, particularly when extramedullary infiltration is a feature.