Applying next-generation sequencing to paired skin and marrow biopsies, Delaleu et al describe an entity they term “myelodysplasia cutis,” comprising histologic features of histiocytoid Sweet syndrome in the skin and a clonally related myelodysplasia in the bone marrow. This can be distinguished from forms of histiocytoid Sweet syndrome not associated with myelodysplastic syndromes, as well as classical neutrophilic Sweet syndrome associated with various malignant and nonmalignant diseases and leukemia cutis where the infiltrating cells are myeloblasts.