Pulmonary Alveolar Proteinosis as a Terminal Complication in a Case of Myelodysplastic Syndrome with Idic(20q-).

Abstract 4864

Secondary pulmonary alveolar proteinosis (PAP) is a rare lung disease which was reported in 13 cases of myelodysplastic syndromes (MDS). A dicentric isochromosome of deleted chromosome 20q i.e., idic(20q-) is a newly recognized rare but recurrent cytogenetic anomaly which has been described in thirty cases of MDS. Recently we encounted an interesting MDS patient with idic(20q-) and secondary PAP. At presentation she was a forty-year-old women manifesting pancytopenia and dysplasia involving two cell lineages which were compatible with refractory cytopenia with multilineage desplasia. Chromosome analysis using R-banding technique showed a karyotype of 46,XX,-20,+a small metacentric chromosomal marker. FISH analysis proved this marker to be a dicentric isochromosome of a deleted 20q. Three yaeas after presentation her disease was complicated by secondary PAP which was confirmed by chest computed tomographic scan and the thoracoscopic lung biopsy which revealed the characteristic periodic acid Schiff stain-positive materials filling the alveoli. After prednisolone and intibiotics freatment, her symptoms had temporary improvement. At last she died of respiratory failure with a survival of 45 months. As we know, no MDS patients with idic(20q-) and secondary PAP have been reported in the literature. Thus, this patient is not only the thirty-first MDS case with idic(20q-), but also the first MDS case with idic(20q-) and secondary PAP.