Recall phenomenon with the unusual presence of eccrine squamous syringometaplasia

The recall phenomenon is an inflammatory reaction limited to a previously X-irradiated field when the patient is treated months or years later with certain drugs. Only a few cases have been reported in dermatological journals. We report a patient with lymphoma who was treated with low-dose abdominal irradiation and high-dose irradiation to the knees and who, 2 months later, when chemotherapy was started, developed a pronounced inflammatory reaction limited to the areas treated with high-dose irradiation. A skin biopsy specimen showed features of radiation damage, marked epidermal changes and extensive eccrine squamous syringometaplasia. This case of the recall phenomenon is of interest because we have found that there is apparently a radiation dose threshold for this event, and because this is the first report of its association with eccrine squamous syringometaplasia.