Sweet's syndrome in a patient with oral cancer associated with radiotherapy.

Approximately 10-20% of the reported patients with acute febrile neutrophilic dermatosis (Sweet's syndrome) have an associated neoplasm. Oral findings of Sweet's syndrome are rarely reported, and no cases in patients with oral cancer have been reported to date. This report describes the clinico- and histopathological findings of Sweet's syndrome in a patient with oral cancer, treated with radiotherapy. After 10 fractions of external beam radiotherapy, treatment was interrupted because of severe oral mucositis which extended beyond the radiation fields. Two days later the patient developed multiple tender skin lesions and the diagnosis Sweet's syndrome was made. Skin and oral lesions resolved without additional treatment and did not recur upon resuming radiotherapy. As suggested in previous case reports, tumour antigens might play a role in the development of Sweet's syndrome. In this case, irradiation therapy may also have been a trigger for this syndrome.