Leukemia subtypes are recognized based on a complex analysis of clinical, morphological, immunophenotype and genetic features. Acute myeloid leukemia (AML) is a highly heterogeneous clonal expansion from the myeloid lineage, representing the most common form of acute leukemia in adults. Leukemic infiltrations in the oral cavity are well described, more frequently representing AML manifestations, usually presenting as a diffuse and reddish gingival swelling, with spontaneous bleeding. In the gnathic bones, myeloid leukemia causes ill-defined radiolucent images. Myeloid sarcoma is a solid mass consisting of myeloblasts, with or without maturation, that develops in extramedullary sites. Males in the sixth decade of life are the most affected individuals. In the oral cavity the gingival tissue is also the most affected location, manifesting as nodules or tumors, usually presenting with a reddish to purple-colored aspect. Microscopic features of myeloid sarcoma vary depending on the degree of differentiation of myeloblasts, and it usually shows a solid proliferation with effacement of tissue architecture by poorly differentiated blast-like cells, which are positive for myeloid markers like myeloperoxidase, CD33, CD43, CD68, CD64, CD163, CD15, CD34 and CD117. The prognosis of patients affected by leukemic infiltrations or myeloid sarcoma varies significantly depending on several prognostic factors.