Hypercalcemia Induced Respiratory Failure as the Primary Presentation in Chronic Myelomonocytic Leukemia

Abstract

Chronic Myelomonocytic Leukemia (CMML) is a rare hematopoietic stem cell disorder characterized by persistent monocytosis and bone marrow dysplasia. Although hypercalcemia is prevalent in various malignancies, its role in CMML-associated respiratory failure remains poorly understood. This report presents a case involving a 69 years old woman with no prior health issues, who presented with symptoms of intermittent fever, dry cough, and generalized weakness. Investigations revealed leukocytosis and an elevated monocyte count. Despite initial treatment with intravenous fluids and antibiotics, her condition deteriorated, manifesting as increased drowsiness and respiratory difficulties. Blood gas analysis revealed elevated pCO2 levels, and an MRI of the brain demonstrated focal temporal lobe enhancement. Neurological assessments were inconclusive; however, due to elevated calcium levels, zoledronic acid was administered alongside intravenous fluids. Following the correction of metabolic abnormalities, her condition improved. Bone marrow aspirate and trephine biopsy findings were consistent with Chronic Myelomonocytic Leukemia I (CMML). This case underscores the importance of considering hematological malignancies in elderly patients presenting with unexplained hypercalcemia and respiratory failure.