8802 A Rare Case Of Symptomatic Hypercalcemia In A Patient With Untreated Chronic Tophaceous Gout

Abstract Disclosure: S. Avula: None. A. Kumar: None. Z.J. Anderson: None. A. Chauhan: None. L.T. LaFave: None. Background: Hypercalcemia is a medical condition with abnormally high serum calcium levels. There are numerous mechanisms for the development of hypercalcemia, but gout is not well documented.Hypercalcemia attributed to Tophaceous gout is a rare phenomenon that is not well studied. Here we report a case of symptomatic hypercalcemia in a patient with a history of untreated tophaceous gout, leading to hypercalcemia and osteolytic lesions. Clinical Case: The patient is a 52-year-old male with a medical history of hypertension, rheumatoid arthritis, and tophaceous gout who immigrated from Tanzania. He presented with two weeks of abdominal pain that acutely worsened the morning of his presentation. He reported a 16-year history of tophaceous gout, for which he had been treated with allopurinol without success. On physical examination polyarticular subcutaneous nodules were present in the bilateral upper and lower extremities, primarily over the joints. There were similar lesions on the buttocks. Initial laboratory evaluation included a complete blood count which was notable for a hemoglobin of 10.3 g/dL (13.1 - 17.5 g/dL). His albumin was normal at 4 g/dl. (3.8 - 5.1 g/dl). Serum calcium was elevated at 12.9 mg/dL (8.8-10.0 mg/dL), with a serum ionized calcium level of 6.52 mg/dL(4.40-5.20 mg/dL). PTH was low at 15.8 pg/mL (16.0 - 65.0 pg/mL), and PTHrP was 2.9 pg/ml (<4.5 pg/ml). Uric acid level on admission was elevated to 11.4 mg/dL (3.4 - 7.0 mg/dL). 1-25 dihydroxy vitamin D elevated at 93.2 pg/mL (19.9 - 79.3 pg/mL). Computed tomography (CT) with intravenous contrast of the chest, abdomen, and pelvis was notable for axillary, pelvic, and inguinal lymphadenopathy concerning for lymphoproliferative or neoplastic processes. Biopsy of right inguinal node biopsy showed benign-appearing lymphoid tissue. Additional findings included multiple lobulated calcified hyperdense foci throughout the subcutaneous and muscular tissues of the buttocks with resorptive changes of the axial skeleton. Spectral CT reconstruction determined these to be uric acid deposits. Radiographs of his extremities were consistent with advanced gouty arthropathy. Infectious work-up was negative. Patient was given 3 liters of 0.9% sodium chloride. He received four doses of Calcitonin (4 units/kg) followed by one dose of Zoledronic acid 5 mg I.V. He was treated with Febuxostat, solumedrol and Azathioprine for his tophaceous gouty arthritis. Conclusion: Hypercalcemia is a commonly encountered yet a very important clinical condition. Parathyroid and malignant etiologies of hypercalcemia account for approximately 90% of cases of hypercalcemia. Gout as the inciting factor for developing hypercalcemia is a rarely documented phenomenon. This case highlights hypercalcemia as an unusual yet severe manifestation of untreated chronic gout and demonstrates the need for additional studies and reviews. Presentation: 6/2/2024