A Rare Concurrence of Myelodysplastic Neoplasia and Tetrasomy 8 in a 3-Year-Old Bahraini Male

Abstract

Myelodysplastic neoplasia (MDS) is a group of stem cell disorders involving ineffective hematopoiesis. It can be associated with an increased risk of progression toward acute myeloid leukemia (AML). In Bahrain, MDS is the fifth most common primary hematologic malignancy. MDS has an annual incidence of up to 4 million cases. Some of the presenting signs and symptoms of MDS are often nonspecific, such as fatigue, pallor, malaise, fevers, bleeding, bruising, weight loss, and anorexia. Approximately 40% of patients with MDS progress to AML. This paper outlines a case of a 3-year-old Bahraini male (known to have sickle cell trait) who presented to the emergency department of Salmaniya Medical Complex with a five-day history of fever, congested throat, left ear pain, and abdominal pain. He had one episode of vomiting gastric content the previous day. He had previously gone to a private clinic with similar symptoms. Physical examination revealed a short neck and short stature, which was found to be below the 5^th percentile. He had generalized pallor and hepatosplenomegaly. A blood smear showed leukopenia and normochromic normocytic anemia. There were excessive blasts found which consisted of 17% of nucleated cells and few granulopoietic cells. Erythropoiesis was active with a few showing mild megaloblastic changes. There were rare megakaryocytes noted. Moreover, the bone marrow aspirate showed two populations on dim CD45. The first population consisted of 3.15% on dim CD45 comprising of hematogones which brightly expressed CD19, HLA-DR, CD79a, and dim CD10. The second population consisted of 14.85% on dim CD45 which expressed CD34, CD13, CD117, HLA-DR, and dim CD7. Based on the peripheral blood smear and bone marrow immunophenotyping findings, a diagnosis of myelodysplastic syndrome with excessive blasts was made, which soon transformed into a diagnosis of AML. Furthermore, increased levels of dysplastic changes and percentage of blasts in the peripheral blood smear and bone marrow lead to a higher possibility of transformation into AML. As per the WHO classification, a diagnosis of MDS needs evaluation of the morphology of blood and bone marrow.

Keywords: acute myeloid leukemia; bone marrow biopsy; cytopenia; myelodysplastic neoplasia; peripheral blood smear; tetrasomy 8.