Isodicentric chromosome 18q as sole abnormality in a histologically normal bone marrow from a patient with diffuse large-cell non-Hodgkin's lymphoma.

Cytogenetic analysis was performed on the histologically and immunophenotypically normal bone marrow (BM) of a 33-year-old woman with non-Hodgkin's lymphoma (NHL) before BM harvest. Unstimulated 24- and 48-hour cultures produced only normal metaphases. A pokeweed mitogen (PWM)-stimulated 48-hour culture, however, showed a clonal isodicentric chromosome 18q as the sole abnormality, suggesting a role for this approach in detection of submicroscopic BM involvement by B-cell NHL.