Herein, we report the case of a 72-year-old male patient who presented with a history of left anterior chest wall painless skin lesions. Histology of skin biopsy of the left chest skin lesion showed diffuse dermal infiltration by monomorphic medium-sized blastic cells positive for cluster of differentiation (CD)4, CD45, CD7, CD56, CD43, CD123, T-cell leukemia-1 (TCL1), and B-cell leukemia/lymphoma 2 protein (BCL2). Given the rarity of the disease, standard chemotherapy regimens used in treating different leukemias and lymphomas have been adapted to treat BPDCN. The gene discussed is NCAM1; the disease is CD4+/CD56+ hematodermic neoplasm.