[Malignant lymphoma following years of hydantoin treatment for epilepsy].

The cases are presented of 4 hydantreated epileptic patients developing malignant lymphomas (1 Hodgkin's lymphoma). The duration of the hydantoin therapy ranged from 7 to 23 years. There was no evidence of an allergic drug reaction, with the exception of slight blood eosinophilia. Prior to the lymphoma one patient exhibited leukopenia and a second thrombocytopenia. Hydantoins were discontinued in 3 cases but the lymphomas never disappeared spontaneously and only once did tumor progression came to a stillstand. Two patients were successfully treated with either chemo- or radiotherapy. Possible correlations between the documented immunosuppressive action of hydantoin derivatives and tumor induction are discussed. Malignant lymphomas may be sequelae of long-term hydantoin therapy and are not always preceded by the well-known reversible hydantoin lymphadenopathy.