Serial cytogenetic alterations resulting in transformation of a low-grade follicular lymphoma to Burkitt lymphoma.

Follicular lymphoma (FL) is the most common indolent or low-grade non-Hodgkin lymphoma (NHL). Histologic transformation to high-grade lymphoma, generally to diffuse large B-cell lymphoma, occurs in 25-35% of cases. Although t(14;18), the cytogenetic hallmark of FL, has been found in approximately 85% of these cases, multiple secondary cytogenetic and molecular genetic changes underlie the transformation process. We report the case of a 58-year-old patient who presented with stage IVA, grade 2 FL that subsequently transformed to Burkitt lymphoma. Multiple chromosomal aberrations, including three novel translocations, were observed related to this transformation. Inversion (1)(p36.3q12) and t(3;14;18)(p23;q32;q21) occurred prior to transformation and may have contributed to the transformation process. A t(1;11)(q25;q13) was acquired simultaneously with t(8;22) and, in conjunction with other chromosomal abnormalities, coincided with an extremely aggressive clinical course. The frequent breakage of 1q observed in this case suggests that the region harbors important genomic signals for the transformation of FL.