Paroxysmal nocturnal hemoglobinuria preceding malignant lymphoma.

We diagnosed lymphoma 14 months after the patient presented with paroxysmal nocturnal hemoglobinuria. To our knowledge, this is the first presentation of both conditions in a patient. One possible explanation is that both conditions could be traced to an alteration in the most primitive hemic stem cell. Such an alteration would have resulted in abnormalities of both lymphoid and nonlymphoid cell lines.