Characteristics of Sweet Syndrome in patients with acute myeloid leukemia.

Introduction: Sweet syndrome (SS) is associated with hematologic malignancies including acute myeloid leukemia (AML).

Patients And Methods: Records of patients with AML treated at our institution were reviewed to identify those with SS. Patient characteristics, laboratory values, and cytogenetic and molecular abnormalities were retrospectively reviewed.

Results: We identified 21 of 2178 (1%) AML patients who demonstrated clinical signs and symptoms, and histological features consistent with SS. Eleven patients (52%) were classified as AML with myelodysplasia-related features and 3 patients had therapy-related AML. Three patients had received treatment with granulocyte colony stimulation factor, 1 patient liposomal all-trans-retinoic acid, and 2 patients received hypomethylating agents before development of SS. Cytogenetic analysis revealed diploid karyotype in 7 patients (33%); -5/del(5q) in 8 patients (38%): 3 patients had -5/del(5q) as the sole abnormality and 5 patients had -5/del(5q) as part of complex cytogenetics; and complex cytogenetics in 5 patients (24%). Gene mutations in FMS-related tyrosine kinase-3 (FLT3) gene were identified in 7 of 18 evaluable patients (39%), including FLT3-internal tandem duplication in 4 patients and FLT3-D835 tyrosine kinase domain mutation in 3 patients.

Conclusion: SS occurs in 1% of AML patients; -5/del(5q) karyotype, FLT3 mutations, and AML with myelodysplasia-related features were more frequent among patients with SS.