Trisomy 22 as the Sole Karyotypic Abnormality in Myelodysplastic Syndrome

Abstract

Trisomy 22 as a sole acquired chromosomal abnormality is an uncommon cytogenetic aberration in hematological malignancies. As far as we know, this abnormality has not been reported in myelodysplastic syndrome (MDS). We report here a unique case of MDS showing trisomy 22 as a sole karyotypic abnormality. An 89-year-old woman was admitted to our hospital in June 2004 because of weakness. She had a history of cerebral infarction at the age of 65. She had anemia that began when she was 80 years old and was diagnosed as being of unknown origin. Physical examination disclosed severe anemia without hepatosplenomegaly or lymphadenopathy. The patient’s temperature was 36.7 C, pulse was 84, and blood pressure was 152/80 mm Hg. Her white cell count was 3.9 109/L, with 64.5% neutrophils, 33.5% lymphocytes, and 2% monocytes. Red cell count was 850 109/L with 1.2% reticulocytes, hematocrit was 8.8%, and hemoglobin concentration was 2.7g/dL. Her platelet count was 323 109/L. A bone marrow aspiration showed hypercellular bone marrow with proliferation of blasts (9.5% of all nucleated cells), decreased erythropoiesis, and trilineage dysplasia. Proliferation of megakaryocytes (4.0% of all nucleated cells) was prominent, and some erythrocytes showed ringed-sideroblastic appearance. A diagnosis of refractory anemia with excess blasts 1 was made according to World Health Organization criteria. Cytogenetic studies of bone marrow cells disclosed 47, XX, +22 [16] (Figure 1), /46, XX [4]. Repeat examination of bone marrow cells a month later showed the same karyotypic abnormality, 47, XX, +22 [16]/46, XX [4]. To detect cryptic rearrangements of major-bcr/abl, PML/RARA, AML1/ MTG8, CBF /MYH11, DEK/CAN, NUP98-HOXA9, MLL/ AF6, MLL-AF9, MLL/AF9, or MLL/ENL, real-time quantitative polymerase chain reaction (RQ-PCR) analyses were performed by SRL (Tokyo, Japan), using their corresponding Trisomy 22 as the Sole Karyotypic Abnormality in Myelodysplastic Syndrome