Objective: To analyze the clinical and cytogenetic features of myelodysplastic syndrome(MDS) associated with del(20q).
Methods: The cytogenetic profiles, clinical manifestations, laboratory data, and transformation in course of disease were analyzed.
Results: (1) Of 29 MDS patients with del(20q), eleven (37.9%) had normal karyotype in addition to del(20q) aberration. Among them, nine patients were categorized into refractory anemia(RA)/RA with ringed sideroblasts(RAS) group and two into RA with excess Hasts(RAEB)/RAEB in transformation(RAEB-T) group. The breakpoint in 20q11 was commonly seen in patients with RA/RAS(63.2%), while del(20q12) was predominant in patients with RAEB/RAEB-T(accounting for 70% in all RAEB/RAEB-T patients). It was observed that RAEB/RAEB-T patients had higher frequencies of extra chromosomal aberrations(50%) and complex karyotype(30%) than did the RA/RAS patients (26.3%, 5.3% respectively); (2) Almost all patients revealed prominent pancytopenia, dyserythropoiesis and dysgranulopoiesis and 58.6% patients showed dysmegakaryopoiesis; positive periodic acid schiff staining of nucleated erythrocytes or reduction of neutrophils were found in 62.5% of patients; 81.8% of patients expressed lymphoid antigens; (3) Two cases transformed to acute myeloid leukemia.
Conclusion: Del(20q) may be an early and primary cytogenetic event in the development of hematologic malignancies. Pancytopenia and dysplasia of bone marrow cells are prominent in patients with MDS associated with del(20q); lymphoid antigen expression is a common occurrence; more additional chromosomal abnormalities and complex karyotypes appear when the disease becomes worse.