[Recurring Sweet syndrome in a patient with Philadelphia chromosome-positive acute lymphoblastic leukemia]

Sweet syndrome is a rare inflammatory disease with rapid onset of painful, edematous skin eruptions, and neutrophilia. Concerning hematological disorders, Sweet syndrome often presents in patients with myeloid diseases, but it is rarely observed in patients with lymphoid diseases. Here we describe a 72-year-old male with Philadelphia chromosome-positive acute lymphoblastic leukemia who suffered recurring Sweet syndrome. Following induction chemotherapy, granulocyte colony-stimulating factors (G-CSFs) were administered due to febrile neutropenia. A few weeks thereafter, skin eruption emerged on the palmar and dorsal surfaces of his hands, and skin biopsy confirmed Sweet syndrome. His symptoms improved with the short-term use of prednisolone. After recovering from the neutropenia, the patient received percutaneous coronary intervention (PCI) due to unstable angina that developed after the induction chemotherapy. During PCI, coronary artery dissection caused cardiopulmonary arrest. The patient recovered with intensive care. However, blood tests on the following day revealed marked neutrophilia. The skin eruption re-emerged on both hands, which was consistent with Sweet syndrome. Sweet syndrome repeatedly occurred after the recovery of neutropenia due to chemotherapy. We suggest that the intrinsic increase in G-CSF in response to inflammation might have caused recurring Sweet syndrome in this patient.