Atypical ringed sideroblasts in association with trisomy 19 and myelodysplasia

Clonal abnormalities are identified by standard cytogenetic analysis of bone marrow cells in 40–50% of individuals with acquired idiopathic sideroblastic anemia/refractory anemia with ringed sideroblasts, a distinctive hematologic illness which is also classified as a form of myelodysplasia. Certain recurring chromosomal abnormalities, including 5q-, 7q-, 20q-, and trisomy 8, are the most frequent examples. Isolated trisomy 19 as a sole clonal aberration in this disorder is a rare event. The case presented here, and which demonstrated 30% involvement of bone marrow cells with trisomy 19, as quantified by fluorescent in situ hybridization studies, appears to represent only the fifth reported instance of such association. An atypical feature in this case was the unique histological appearance of the excessive cytoplasmic mitochondrial-associated iron deposition present in 30% of the bone marrow erythroid precursors as large chunks of Prussian blue-staining material rather than the individual, punctuate, multiple iron granules typically evident in refractory sideroblastic anemias.