Van den Berghe's 5q- syndrome and myelodysplastic syndrome with isolated del(5q)

The del(5q) cytogenetic abnormality was first described by Van den Berghe et al. in 1974. 1 The original manuscript described five patients with a macrocytic anemia, dyserythropoiesis with erythroid hypoplasia, normal to elevated platelet count, hypolobulated megakaryocytes and an interstitial deletion involving the long arm of chromosome 5. However, a deletion of chromosome 5q in myelodysplastic syndrome (MDS) does not necessarily equate to the clinically described 5q-syndrome because, by definition, the 5q-syndrome is a distinct entity with the aforementioned clinical characteristics. 2 As we routinely evaluate patients with suspicion of MDS, some unusual clinical situations have emerged in our clinical practice. In December 2013, a 65-year-old asymptomatic woman was referred to us to investigate isolated leukopenia. The physical exam was normal. The complete blood count showed mild leukopenia (white blood cells 2.65 × 10 9 /L – neutrophils 36%, eosinophils 8%, basophils 0%, lymphocytes 48% and monocytes 8%), hemoglobin 12.3 g/dL (normal range 11.5–16.4 g/dL), mean corpuscular volume (MCV) 101.1 fL and platelets 326 × 10 9 /L. The patient was submitted to bone marrow (BM) aspiration and biopsy, as well as cytogenetic analysis by G-banding. The BM smear revealed a normocellular erythrocyte lin-eage, characterized by the presence of dysplasia in 12% of cells. The megakaryocytic lineage was hypercellular and characterized by dysplasia in 28% of cells. The morphologically abnormal megakaryocytes exhibited a non-lobulated, eccentric nucleus (Figure 1a). Occasionally, 'dumbbell-type' megakaryocytes were identified (Figure 1b). The BM biopsy showed overall hypocellularity and confirmed the significant dysmegakaryopoiesis. Dyserythro-poiesis was characterized by megaloblastoid erythroblasts (<10%). The granulocytic series showed no significant abnormalities. Following the recommendations of the International System for Human Cytogenetic Nomenclature (ISCN 2013), the cytogenetic analysis demonstrated a karyotype with a large interstitial deletion in the long arm of chromosome 5 (5q22) in 50% of 16 analyzed metaphases (46,XX,del(5)(q22)[8]/46,XX[8]) (Figure 1c). The patient's last medical consultation took place in June 2015 and she was asymptomatic. She continues to be followed by her local hematologist. In March 2015, the hemoglobin level dropped to 10.6 g/dL. The last complete blood count dated June 2015 showed white blood cells of 1.64 × 10 9 /L – neutrophils 23.9%, eosinophils 5.2%, basophils 0.5%, lymphocytes 61.6%, monocytes 8.8% – hemoglobin 9.9 g/dL, MCV 109.1 fL, and platelets 195 × 10 9 /L. The median value and the minimum–maximum value for hemoglobin, and neutrophil and platelet counts during the period of the follow up were Myelodysplastic …