• In vitro and in vivo immunologic studies were performed on a 28-year-old woman with phenytoin sodium-induced pseudolymphoma syndrome. During the acute phase of the syndrome, the patient appeared immunologically depressed. Six months after resolution of lymphadenopathy, repeat studies demonstrated a return to immunologic competence. In vitro studies of the patient's lymphocytes when incubated with phenytoin failed to indicate a delayed hypersensitivity reaction to the drug. These findings suggest that the patient developed a clinical lymphatic proliferation at a time when she was immunologically depressed. This may result in an increased chance of a mutant malignant clone developing at a time when the immunosurveillance system is impaired and explains why a rare patient with this syndrome may develop a frank malignant lymphoma.
(Arch Dermatol 113:477-480, 1977)
Ernest N. Charlesworth. Phenytoin-Induced Pseudolymphoma SyndromeAn Immunologic Study. Arch Dermatol. 1977;113(4):477–480. doi:10.1001/archderm.1977.01640040085013