Endocrine Abstracts

Introduction: Acute lymphoblastic leukaemia (ALL) can present with hypercalcaemia in infancy. We describe a 10-month-old boy with B-ALL who presented with hypercalcaemia and multiple fractures, including vertebral fractures (VF), where diagnosis required multiple bone marrow biopsies. This case also raises important questions about the duration of bisphosphonate therapy and the role of routine spine imaging in ALL.

Case: The infant presented with a one-month history of vomiting, fever, lethargy, and reduced oral intake. There were no signs of bruising, night sweats, or organomegaly. Blood tests revealed marked hypercalcaemia (adjusted calcium 4.81 mmol/l), undetectable parathyroid hormone (PTH), normal 25-hydroxyvitamin D, and evidence of acute kidney injury. Full blood count showed mild normocytic anaemia; the blood film was unremarkable. Imaging revealed generalised osteopenia, multiple VF, anterior rib, and long bone fractures. Dense bones were not observed, making osteopetrosis unlikely. Whole-body MRI showed no additional pathology but suggested an infiltrative process. Diagnosis of B-ALL was confirmed after three bone marrow biopsies over six weeks. Hypercalcaemia was managed with two courses of IV pamidronate. Given ongoing corticosteroid and chemotherapy use, regular IV zoledronate was initiated for bone protection. Spine radiographs at 10 months post-diagnosis showed evidence of vertebral reconstitution, with stable appearances on subsequent imaging.

Discussion: This case highlights the diagnostic complexity of ALL in infants, where obtaining adequate marrow samples can be technically challenging. Diagnosis must be confirmed before commencing chemotherapy to allow appropriate monitoring of treatment response. It also raises key considerations in the management of VF in ALL. Studies suggest 16% of children have VF at diagnosis with routine spine imaging and 25% may develop new VF during treatment. While many children with ALL and VF may undergo spontaneous vertebral reshaping without bisphosphonates, the optimal duration of treatment in symptomatic cases remains uncertain. The role of routine spinal imaging at diagnosis and with follow-up, particularly in asymptomatic patients, also warrants further investigation. We propose an age-stratified monitoring and management approach, informed by current evidence, to guide bisphosphonate use and spine imaging in paediatric ALL.