Clonal evolution in the transition from cutaneous disease to acute leukemia suggested by liquid biopsy in blastic plasmacytoid dendritic cell neoplasm.

We have detected novel mutations in TET2 and RHOA genes in a case of blastic plasmacytoid dendritic cell neoplasm (BPDCN). Analysis of peripheral blood mononuclear cell (PBMNC) samples at two timepoints allowed inference of subclonal variation associated with the evolution of acute leukemia from cutaneous disease. Blastic plasmacytoid dendritic cell neoplasm is a rare disease, which is now regarded as myeloid-related.1 There is a male preponderance (M:F 3:1), and patients typically present with cutaneous lesions, which might include nodules, patch-plaques or bruise-like areas. Bone marrow (60-90%) and lymph nodes (40-50%) might also be involved, while low-level peripheral blood involvement is a recognized feature of the disease.2,3 While some cases remain cutaneous, others develop acute myeloid leukemia, which is often metachronous.3 Prognosis is poor with a median overall survival of 12-14 months, although combination chemotherapy followed by allogeneic stem cell transplantation appears to offer the possibility of cure for some patients.4