Trisomy 13 in a patient with idiopathic myelofibrosis

Although trisomy 13 has been reported as a recurring abnormality in acute myelocytic leukemia [1], it has been rarely described in other hematological diseases, particularly in chronic myeloproliferative disorders. We report here a case of a 79-year-old male patient with idiopathic myelofibrosis showing a trisomy 13 at cytogenetic analysis upon diagnosis. The patient was referred to our division because of leukocytosis, anemia, and thrombocytopenia. Physical examination showed marked hepatomegaly and splenomegaly. A peripheral blood sample showed hemoglobin 9.6 g/dL, platelets 50 × 10/L, and white blood cells 60 × 10/L with 60% neutrophils, 10% lymphocytes, 20% myelocytes, 5% metamyelocytes, 5% monocytes, and rare erythroblasts. Poikilocytosis with dacryocytes was observed. Analysis of bone marrow biopsy showed hypercellularity and was consistent with a diagnosis of idiopathic myelofibrosis in the cellular phase. Cytogenetic analysis was performed with a Wright–Giemsa banding technique on a bone marrow aspirate. We examined metaphase cells from shortterm unstimulated cultures at 37 C in RPMI-1640 medium, supplemented with 10% fetal calf serum. Chromosomal abnormalities were described according to ISCN 1995 [2]. The karyotype showed 47,XY, 13[19]/46,XY[1]. As of writing, the patient was in good clinical condition, after being treated with hydroxyurea 1 g/d with stable disease at 6 months follow-up. Trisomy 13 is associated predominantly with undifferentiated acute myelocytic leukemia (AML, M0), but a few cases of myelodysplastic syndrome have been reported [3], with a highly variable prognosis: 4 months to 10 years of survival. Trisomy 13 affects predominantly older men and there is a possible association with previous chemoradiotherapy. No