Structural chromosomal abnormality of 1q in acute leukemia with Sweet syndrome

Insights Into the Pathogenesis of Sweet's Syndrome

Sweet's syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. It is considered to be the prototype disease of neutrophilic dermatoses, and presents with acute onset dermal neutrophilic lesions, leukocytosis, and pyrexia. Several variants have been described both clinically and histopathologically. Classifications include classic Sweet's syndrome, malignancy associated, and drug induced. The cellular and molecular mechanisms involved in Sweet's syndrome have been difficult to elucidate due to the large variety of conditions leading to a common clinical presentation. The exact pathogenesis of Sweet's syndrome is unclear; however, new discoveries have shed light on the role of inflammatory signaling, disease induction, and relationship with malignancy. These findings include an improved understanding of inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic contributions. Continued investigations into effective treatments and targeted therapy will benefit patients and improve our molecular understanding of inflammatory diseases, including Sweet's syndrome.

Clonal neutrophil infiltrates in concurrent Sweet's syndrome and acute myeloid leukemia: A case report and literature review

Sweet's syndrome (SS), also known as acute febrile neutrophilic dermatosis is often associated with a hematological malignancy, especially acute myeloid leukemia (AML) and myeloid dysplasia syndrome. Histopathologically, SS is characterized by diffuse infiltrates in the upper dermis, predominantly consisting of mature neutrophils. The origin of neutrophils invading the skin remains unknown. Herein, we report a patient with concurrent acute monoblastic leukemia and SS who initially presented with discrete erythematous papules and nodules on the neck. Single nucleotide polymorphism (SNP) array and next generation sequencing (NGS) revealed a concordant fms-related tyrosine kinase-3 (FLT-3) gene mutation in the bone marrow and skin lesion, indicating that the neutrophilic infiltrates were clonally related to the underlying myeloid neoplasm. This is the first case report of concurrent SS and AML, in which SNP array and NGS analysis were applied to confirm the clonality of the neutrophilic infiltrates.