P-032 PAGET’S DISEASE PRESENTING WITH PROFOUND HYPOCALCEMIA AND MASSIVE SKULL INVOLVEMENT: A RARE CLINICAL MANIFESTATION

Abstract Introduction Paget's disease of bone is a metabolic bone disorder characterized by abnormal bone remodeling and is often detected incidentally through elevated alkaline phosphatase (ALP) or pathological fractures. Presentation with severe hypocalcemia is unusual. Here, we describe a rare case of Paget's disease admitted to the emergency department with profound hypocalcemia and extensive cranial bone involvement. Clinical Case A 64-year-old woman presented with progressive somnolence and speech difficulties. Neurological evaluation revealed disorientation with a Glasgow Coma Scale score of 11, frontal and temporal bone prominence, and increased head size. Cranial changes had gradually progressed over the previous four years, with hearing loss and recurrent headaches emerging during the last two years. Her vital signs were stable. Chvostek’s and Trousseau’s signs were positive. Arterial blood gas analysis revealed pH 7.39, bicarbonate (HCO₃⁻) 30 mmol/L, and ionized calcium 2.3 mg/dL. Brain CT and diffusion MRI excluded acute stroke and intracranial hemorrhage. ECG demonstrated a prolonged QT interval of 490 ms. Laboratory tests showed severe hypocalcemia (Ca: 4.1 mg/dL), low phosphorus (2.1 mg/dL), markedly elevated ALP (1550 U/L), low vitamin D (