Incidental Hypercalcemia: The Sole Presentation of B-Cell Acute Lymphoblastic Leukaemia

Abstract

This article aims to report a sole presentation of B-cell acute lymphoblastic leukaemia (ALL) as incidental hypercalcemia. ALL is the most frequent neoplastic disease in children, with an early peak at the age of 3–4 years. ALL presents with neutropenic fever, bruising, anaemia, lymphadenopathy and bone pain. Presenting features as manifestations of hypercalcemia in ALL is extremely rare, especially in adults. More than 90% of causes of hypercalcemia are primary hyperparathyroidism and malignancy. Hence, if parathyroid hormone (PTH) levels come low, malignancy is the most probable aetiology. Hypercalcemia associated with malignancy includes three distinct syndromes. Bone metastases may cause hypercalcemia. Direct bone marrow invasion occurs with hematologic malignancies such as leukaemia, lymphoma and multiple myeloma. Hypercalcemia is seen in <1% of cases of leukaemia. A 16-year-old male presented with nausea, vomiting, abdominal pain and burning micturition. Physical examination was unremarkable except for pallor. His laboratory studies showed haemoglobin 5.7g/dL, white cell count 5700/mm3, platelet count 51,000/dL, and serum calcium 17.1 mg/d. He was hydrated and given zoledronate IV, with which calcium level normalised and symptoms resolved. The patient had low PTH and low parathyroid hormone-related peptide (PTHrp). Peripheral smear and bone marrow showed lymphoblasts. Flow cytometry confirmed B-cell ALL with 43% blasts. Hypercalcemia revealed B-cell ALL in an adult after a thorough workup of low PTH and PTHrp, peripheral blood picture, bone marrow examination, and flow cytometry. Hence, ALL should be considered in the differential diagnosis of a young adult presenting with incidental hypercalcemia.