CNTN2 and T-cell non-Hodgkin lymphoma: Our patient had missense mutations in the FLT3 and PTPRB genes, which are associated with myeloid sarcoma; missense mutations in LTK (associated with poorly differentiated cancer), NOTCH2 (associated with diffuse large B-cell tumor), and CNTN2 (associated with T-cell lymphoma); and a frameshift deletion mutation in the oncogene TP53. We also reviewed the relevant literature from 1990 to 2021, and identified 10 cases of myeloid sarcoma with monocytic differentiation.