Recurrent chromosomal defects are found in most patients with non-Hodgkin's-lymphoma.

Using methotrexate cell synchronization, we successfully analyzed chromosomal preparations of 40 lymph node biopsies and one bone marrow sample from 44 patients with non-Hodgkin's, non-Burkitt's lymphoma. All of the 41 patients successfully analyzed showed clonal chromosomal abnormalities. In 25 of the 41 (61%), the defects were found to be consistent with (A) a deletion 6q in five of seven patients with diffuse large cell lymphoma, (B) a t(11;14), a del 11q, or a + 12 in seven of nine patients with small cell lymphocytic lymphoma, and (C) a t(14;18) in 12 of 15 patients with follicular lymphoma (small cleaved and mixed small and large cleaved) and in a single case of diffuse large cell lymphoma. In three patients with small cell lymphocytic lymphoma whose biopsies exhibited a t(11;14), lymphocytes were cultured and chromosomes examined for the presence of fragile sites. In two, frequent breaks at band 11q13.3 were observed. Such findings suggest a possible relationship between a fragile site and a predisposition to a specific chromosomal rearrangement in human neoplasia.