Myelodysplastic syndromes with del(20q) transformed into B-lineage acute lymphoblastic leukemia remaining with del(20q): a case report with literature review

The transformation of myelodysplastic syndromes (MDS) into acute myeloid leukemia (AML) is common, while it is extremely rarely for acute lymphoblastic leukemia (ALL) transformation. Herein, we described the clinical and cytogenetic features of a case of MDS with del(20q) transformed into B-lineage ALL (B-ALL) remaining with del(20q). A 66-year-old Chinese man who presented with pancytopenia, bone marrow hypercellularity and obvious megakaryocytes dysplasia were admitted for treatment. Karyotype analysis of leukemic cells revealed the clonal abnormality of del(20q) and he was diagnosed with MDS carrying del(20q). He was administrated with Danazol, cyclosporin A, and lenalidomide for 3 months, and then discontinued due to poor efficacy, severe swelling and aching of gum. He was subsequently treated with Chinese herbs and uninterrupted platelet infusion. After 41 months, this patient evolved into B-ALL. Cytogenetics demonstrated that in addition to the previous abnormality of del(20q), an emerging clonal abnormality of + 21 was observed. Unfortunately, the patient failed to achieve remission after receiving conventional treatment and other symptomatic supportive treatment. This study reported a rare case of B-ALL with del(20q) following MDS with del(20q), and conducted a literature review to explore the clinical features and potential mechanisms of disease transformation in patients with MDS progression to ALL. Collectively, this study will help enrich the knowledge of MDS progression to ALL.