Pseudolymphome sous-cutané postvaccinal de survenue tardive

Persistent subcutaneous nodules arise on rare occasions at sites of injection of aluminium hydroxide-adsorbed vaccine. We report a case following a diphtheria, tetanus and pertussis vaccination. The late onset of the lesion, four years after the injection, led to an uncertain preoperative diagnosis. Histopathologic examination showed features of a subcutaneous pseudolymphoma. The demonstration of aluminium by Morin staining and atomic absorption spectrometry on a paraffin-embedded tissue probe supported the diagnosis of a vaccination-induced pseudolymphoma.