A Case of Fulminant Myelodysplastic Syndrome Versus Acute Erythroleukemia Variant.

Case: A 73 year old male with no significant past medical history presented with chronic fatigue. A routine CBC revealed an H/H of 6.8/19, MCV 103, WBC 4,100 and platelet count 92,000. Reticulocyte count was 0.6%. Serum iron, B₁₂ and red cell folate studies were within normal limits. A bone marrow aspiration and biopsy were performed.

Bone Marrow Findings: The bone marrow aspirate showed an M:E ratio of 1.8:1, with 33% erythrocytic elements. There was markedly left shifted erythropoiesis, with 57% of erythrocytic precursors being pronormoblasts. 1.2% blasts were present. Moderate erythrocytic dysplasia was present, with mild granulocytic and megakaryocytic changes. Vacuolated pronormoblasts were readily identified. No ringed sideroblasts were present. A diagnosis of MDS, NOS was rendered. No cytogenetics were obtained.

Follow-up: The patient was transfused 4 units of packed red cells. Due to the patient’s rapidly deteriorating condition, comfort measures only were provided. The patient died 2.5 weeks after the bone marrow procedure. No autopsy was performed. The cause of death was listed as MDS.

Discussion: This case is an extremely rare instance of left shifted erythropoiesis in the absence of the requisite number of erythrocytic elements for consideration of acute erythroleukemia (50%). By current definitions, this is an example of a fulminant MDS. However, this case does beg the question of whether or not pronormoblasts should be included in the assessment of malignant disorders of bone marrow.