A transient dermatologic abnormality which gave a histologic picture compatible with malignant lymphoma is described. The clinical manifestations included diarrhea, hepatosplenomegaly, moderate lymph node enlargement without histopathological changes and evidence of involvement of the reticulo-endothelial system. Both the dermatologic and gastrointestinal disorders appeared approximately 1 year after discontinuation of treatment with diphenylhydantoin, which the patient had taken for 2 years. The possible association between the transient abnormality and the previous diphenylhydantoin therapy justifies the classification of this case as ‘pseudolymphoma syndrome