RESUMO
BACKGROUND: The Coexistence of myeloid and lymphoid malignancies is rare. Myeloid leukemia occurs more frequently as a secondary event in patients receiving chemotherapy agents for lymphoid malignancies. Synchronous diagnoses of diffuse large B-cell lymphoma (DLBCL), acute myeloid leukemia (AML), and untreated lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) in the same patient have not been reported. Here we report one such case. CASE SUMMARY: An 89-year-old man had a chest wall mass histopathologically diagnosed as DLBCL. The bone marrow and peripheral blood contained two groups of cells. One group of cells fulfilled the criteria of AML, and the other revealed the features of small B lymphocytic proliferative disorder, which we considered LPL/WM. Multiple chromosomal or genetic changes were detected in bone marrow mononuclear cells, including ATM deletion, CCND1 amplification, mutations of MYD88 (L265P) and TP53, WT1 overexpression, and fusion gene of BIRC2-ARAP1, as well as complex chromosomal abnormalities. The patient refused chemotherapy because of old age and died of pneumonia 1 mo after the final diagnosis. CONCLUSION: The coexistence of DLBCL, AML, and untreated LPL/WM in the same patient is extremely rare, which probably results from multiple steps of genetic abnormalities. Asymptomatic LPL/WM might have occurred first, then myelodysplastic syndrome-related AML developed, and finally aggressive DLBCL arose. Therefore, medical staff should pay attention to this rare phenomenon to avoid misdiagnoses.