Complete Bone Marrow Necrosis with Charcot-Leyden Crystals Caused by Myeloid Neoplasm with Mutated NPM1 and TET2

Bone marrow necrosis (BMN) has various underlying diseases. In hematological malignancies, both lymphoid and myeloid neoplasms have been shown to cause BMN. Charcot-Leyden crystals (CLCs) are bipyramidal crystals that have been found in patients with immune system diseases, tumors, skin diseases, asthma, infections, and intestinal diseases. Because the combination of CLCs and acute myeloid leukemia (AML) is rare, the relationship between BMN, CLCs, and AML remains largely unexplored. We herein report a suspected case of AML that was difficult to diagnose morphologically because of complete BMN with CLCs but achieved complete hematologic remission with treatment similar to that for AML.