Case 1
Patient 1 was a 67-year-old woman with no relevant past medical history. She initially presented with a persistent fever for 15 days in August 2017. Computed tomography (CT) detected multiple abdominal lymphadenopathies and splenomegaly. During hospitalization, laboratory tests revealed a hemoglobin level of 87 g/L and a platelet count of 50× 109/L. Flow cytometry was used to detect abnormal cells in the bone marrow, and two masses of abnormal cells were identified.
a) B-lymphocytes (11.03%) positive for CD19, CD20, CD200, and cKappa, and negative for CD5, CD10, CD103, CD25, CD11c, mlambda, mkappa, clambda, and CD38.
b) Plasma cells (14.1%) positive for CD38, CD138, CD71, CD13, and CD19, with ckappa and CD20 moderately expressed, but negative for CD5, CD10, clambda, CD103, CD11c, mlambda, mkappa, CD200, CD25, CD56, and CD117.
The initial bone marrow biopsy also identified a cluster of large B lymphocytes that tested positive for CD20, PAX5, CD38, and MUM1 and negative for CD3 and CD5. Additionally, chromosomal analysis of bone marrow cells indicated the presence of complex chromosomal aberrations (Table 1). Subsequent fluorescence in situ hybridization (FISH) confirmed the rearrangements of MYC, BCL2, and IgH, confirming the diagnosis of DLBCL according to the World Health Organization (WHO) classification.
The patient underwent definitive treatment with 4 cycles of the R-CHOP (Rituximab 375 mg/m2 D1, Cyclophosphamide 750 mg/m2 D1, Doxorubicin 50 mg /m2 D1, Vincristine 1.4 mg/m2, and prednisone 100 mg orally D1–D5) regimen from August to November 2017. Post-treatment positron emission tomography computed tomography (PET-CT) and a repeated bone marrow biopsy confirmed a complete metabolic response after 4 cycles of treatment. Subsequently, the patient received high-dose Busulfan–Cyclophosphamide (BuCy) chemotherapy in combination with autologous hematopoietic stem cell transplantation (auto-HSCT). Maintenance Rituximab therapy was administered for two cycles following the auto-HSCT until May 2018.
Regrettably, the patient complained of fatigue, and subsequent hematological examination indicated pancytopenia in April 2019. Bone marrow examination revealed the presence of 22% myeloid blasts. Cell surface marker analysis showed positive results for CD4, CD13, CD33, and HLA-DR and negative results for CD3, CD8, CD10, CD19, CD20, CD14, CD34, and CD58, which were consistent with AML. Whole-genome sequencing identified the GC (Arg/Pro) genotype of the SNP rs1042522 and SH2B3 tryptophan262arginine polymorphism in bone marrow leukocytes. Unfortunately, the patient passed away in August 2019 due to severe infection. The timeframe for patient treatment and the evolution of Case 1 are shown in Figure 1.
Case 2
A 27-year-old man initially presented with stomachache. Histopathological examination of the gastroscopic biopsy specimen revealed that the B cells exhibited a diffuse growth pattern and large lymphocytes. Immunohistochemical analysis indicated that these large cells tested positive for CD20, CD8, CD4, CD10, Bcl-6, Bcl-2, and C-myc, with a Ki-67 index of 70%. The cells tested negative for CD3, CD56, CD30, Mum-1, ALK, and EBER. Based on the Hans algorithm, it was classified as an activated B-cell (ABC) type of DLBCL. FISH analysis for rearrangements of MYC, BCL2, and BCL6 also yielded negative results. No somatic mutations related to lymphoma were identified using whole-genome sequencing. The GG (Arg/Arg) genotype of the SNP rs1042522 and SH2B3 tryptophan262arginine polymorphism were also detected in this patient. The patient underwent definitive treatment with eight cycles of R-CHOP (rituximab 375 mg/m2 D1, cyclophosphamide 750 mg/m2 D1, doxorubicin 50 mg/m2 D1, vincristine 1.4 mg/m2, and prednisone 100 mg orally D1–D5) until December 2017. PET-CT was utilized for assessing the response in the middle and post-therapy stages, which indicated a complete metabolic response. After nine months, routine hematological examination revealed a notable increase in the monocyte ratio. Further examination of the patient's bone marrow revealed 57.91% myeloid blasts, along with a recurrent chromosomal abnormality, t (9;11) (p22; q23), indicating progression to AML.
Based on the available data, the patient was diagnosed with AML-M5. Whole-genome sequencing revealed the presence of a WT1 gene mutation and MLL-AF9 fusion, both of which are associated with poor survival outcomes in AML. The patient underwent induction chemotherapy with a 7/3 regimen of cytarabine (100 mg/m2 for 7 days) and idarubicin (12 mg/m2 for 3 days). A repeat bone marrow biopsy performed 30 days post-induction confirmed complete remission, which was sustained CR after two cycles of chemotherapy. The patient underwent allogeneic stem cell transplantation (allo-SCT) in January 2019. Transplantation was preceded by a BuCy myeloablative conditioning regimen. Unfortunately, the patient passed away 90 days after the allo-SCT because of severe graft-versus-host disease (GVHD). The timeframe for patient treatment and the evolution of Case 2 are shown in Figure 2.