Sweet syndrome: long-term follow-up of 138 patients

Several studies support a strong association of Sweet syndrome (SS) with malignancy. However, only a few studies analysing the clinical features of malignancy-associated SS have been published in recent years.

To retrospectively study the clinical features of SS that could predict the development of associated malignancies and to analyse the development of malignant neoplasia during long-term follow-up of patients with SS.

Clinical features of the patients diagnosed with SS syndrome between 1987 and 2013 at Bellvitge Hospital (Barcelona, Spain) were retrospectively analysed.

In total, 138 patients were included in the study (66 male, 72 female, mean ± SD age 51.24 ± 14.11 years). SS was associated with haematological malignancy in 31 cases, infection in 23, inflammatory bowel disease in 12, inflammatory systemic disease in 8, and solid tumours in 4. It was drug-induced in 5 cases and idiopathic in 54. In four patients, an underlying haematological disease that was considered related to SS was diagnosed between 4 and 16 months after SS presentation. Variables significantly associated with malignancy in multivariate logistic regression analysis were age (OR = 1.08 for each increasing year, P = 0.01), anaemia (OR = 9.38, P = 0.001), thrombocytopenia (OR = 16.10, P < 0.01) and absence of arthralgia (OR = 11.13, P < 0.01).

Patients with older age, anaemia or thrombocytopenia, and without arthralgia are more likely to have malignancy-associated SS. We recommend that patients with SS without clear aetiology should be followed up for at least 16 months to exclude a possible underlying haematological malignancy.