Laboratory divergences in concurrent diagnosis of acute myeloid leukemia relapse and COVID‐19: A case report

Abstract

Dear Editors, Although acute myeloid leukemias (AML) are well known and are not rarely reported, in time of coronavirus disease 2019 (COVID19) pandemic, diagnosis, followup, and care of patients with AML can become a huge challenge for clinicians and clinical laboratory specialists, due to a lack of experience and the presence of divergences in both clinical examination and laboratory results. A 61yearold patient in complete remission for 6 years for an AML with maturation diagnosed with trisomy 8 and treated by allogeneic stem cell transplantation (SCT), was admitted in the emergency department for a flu syndrome with productive cough, headaches, anosmia, and ageusia. At the admission, physical examination showed only a mild hypoventilation. Chest computedtomography (CT) scan revealed no abnormalities suggestive of severe acute respiratory syndrome coronavirus 2 (SARSCoV2) infection. Nasopharyngeal swab was realized for SARSCoV2 polymerase chain reaction (PCR) detection and bone marrow (BM) aspirate was performed due to the patient s AML history. Laboratory tests indicated an inflammatory syndrome (Creactive protein 30.5 mg/L), a pancytopenia (hemoglobin 10.9 g/ dL, white blood cells count 1.13 × 109 cells/L, and platelets count 66 × 109 cells/L), and the presence of multiple plasma cells (5.5%) and activated lymphocytes (4.5%) in the peripheral blood smear (Figure 1). The BM aspirate smear revealed a fibrous marrow with a mild lymphocytosis (23%) characterized by the presence of few activated lymphocytes and some plasma cells (approximately 5%), both were also previously noticed in the peripheral blood sample. Otherwise, a large blast population (approximately 24%) was visualized in the BM but was not found in peripheral blood smear (Figure 2). Flow cytometry immunophenotypic analysis identified the presence of 5% myeloblasts, with weak CD45, HLADR, CD34, CD117, strong CD33, weak CD11c, weak CD15, and CD13 expression confirming the increased blast population seen in BM aspirate smear and the probable relapse of AML. SARSCoV2 PCR detected the presence of the virus in the nasopharyngeal swab of the patient and confirmed the COVID19 disease, despite negative chest CT scan and absence of severe respiratory symptoms. Morphological anomalies of circulating blood cells in COVID19 patients were already reported and could be caused by cytokine storm and inflammatory syndrome, two pathogenic factors of the SARSCoV2 infection.13 In this case, presence of plasma cells and activated lymphocytes in both peripheral blood and BM smear samples highlighted the reactive state caused by the SARSCoV2 infection while the homogeneous blast population only found in the BM sample showed the probable relapse of AML. AML relapse of the patient was confirmed by the cytogenetic analysis. Indeed, the majority of mitoses analyzed in the BM sample