Acute Pancreatitis in the Context of Hypercalcemia: Unveiling Multiple Myeloma

Background Acute pancreatitis (AP) is an inflammatory condition of the pancreas, commonly triggered by gallstones or alcohol consumption. Hypercalcemia, although rare, is a recognized cause of AP, accounting for 1.5% to 8% of cases, typically due to primary hyperparathyroidism. Multiple myeloma (MM), a hematological malignancy characterized by clonal plasma cell proliferation, is an uncommon source of hypercalcemia and an even rarer cause of AP. While MM generally presents with anemia, bone pain, and renal impairment, hypercalcemia-induced AP as an initial manifestation is highly unusual and poses diagnostic challenges with meticulous clinical judgement. Case Presentation A 62-year-old male presented with severe epigastric pain radiating to the back, accompanied by nausea and vomiting. Laboratory tests revealed anemia, renal impairment, and elevated serum calcium levels. Imaging confirmed AP, while common causes like gallstones were excluded. Despite normal parathyroid hormone levels and no obvious bone metastases, an elevated erythrocyte sedimentation rate (ESR) raised suspicion for a hematological malignancy. Initial investigations, including serum protein electrophoresis and urine testing for Bence Jones protein, were inconclusive. However, a bone marrow biopsy confirmed the diagnosis of MM as the underlying cause of hypercalcemia-induced AP. Conclusion This case underscores the diagnostic complexity of hypercalcemia-induced AP, particularly when it is secondary to an uncommon cause like MM. Clinicians should consider MM in patients with unexplained hypercalcemia, even when initial tests are inconclusive, to avoid delays in diagnosis and treatment, which are crucial for improving patient outcomes.