Case 416

Submitting Author: Jaso, Jesse Manuel, MD
Institution: University of Texas MD Anderson Cancer Center, Univerity of Texas Medical School at Houston
Additional authors:Alyaa Al-Ibraheemi, M.D., Amer Wahed, M.D.
Session: Erythroleukemia and megakaryoblastic AML and mimics

HISTORY

The patient is a 56-year-old male who was presented with chest pain, shortness of breath, and fatigue. His symptoms rapidly progressed and he became obtunded. He WAS admitted to the Intensive Care Unit. Peripheral blood smear showed pancytopenia and a bone marrow aspiration and biopsy was performed.

DETAILS

Bone marrow aspirate, clot section, and biopsy were obtained from the left posterior iliac crest using standard techniques. The biopsy and clot sections were fixed in formalin and stained with hematoxylin and eosin after decalcification of the biopsy. The aspirate smears were air-dried and stained with Wright-Giemsa. The bone marrow aspirate showed increased erythroid precursors (76%) with marked dysplasia including nuclear membrane irregularities and mild cytoplasmic vacuolization. Blasts were mildly increased (7% as a total of non-erythroid cells). The granulocyte lineage showed normal maturation and no significant dysplasia. Differential: Myeloblasts: 1 Promyelocytes: 0 Myelocytes: 9 Metas: 1 Bands & PMN's: 3 Eos: 3 Baso: 0 Monos: 2 Lymphs: 5 Plasma cells: 0 Erythroids: 76 M:E ratio: 0.25:1 The bone marrow clot section was aparticulate. The bone marrow core was suboptimal due to crush artifact and mostly sub-cortical location. The preserved intra-trabecular spaces showed predominantly eyrthoid precursors.

IMMUNOHISTOCHEMISTRY AND FLOW CYTOMETRY

Flow cytometric immunophenotyping did not reveal an aberrant B-cell or T-cell population, and an increase in CD34-positive blasts was not identified.

CYTOGENETIC FINDINGS

Diploid karyotype

MOLECULAR FINDINGS

No molecular analysis was performed.

INTERESTING FEATURES

The intial impression, based on the morphologic findings, was Myelodysplastic Syndrome (MDS) vs Erythroleukemia. Upon further investigation, the patient was found to have an extremely elevated lactate dehyrdogenase level (LDH), increased bilirubin, and decreased haptoglobin. The patient responded to supportive therapy and his neurological status improved. The patient mentioned a history of sickle cell disease/beta thalassemia and stated that he had been recently transfused. This case highlights the difficulty in evaluating cases with ≥50% erythroid precursors. Based on the number of erythroid cells, increased blasts, and dyserythropoiesis the differential diagnosis includes Erythroleukemia. However, the sudden onset of disease, as well as the presence of a normal granulocyte population undergoing orderly maturation argue against the diagnosis. The presence of severe hemolysis and the history of sickle cell disease/beta thalassemia and the rapid response to supportive therapy suggest that the morphologic findings represent reactive erythroid hyperplasia due to severe hemolysis of an unknown cause. In summary, this case highlights the need to rule out reactive causes of erythroid hyperplasia in the work-up of cases with ≥50% erythroid precursors. Such cases require coordination of clinical and laboratory data, along with ancillary studies. This case also highlights the limitations imposed by a sub-optimal specimen.

PROPOSED DIAGNOSIS

REACTIVE ERYTHROID HYPERPLASIA

CONSENSUS DIAGNOSIS

Reactive erythroid hyperplasia