Hypercalcemia- A Common Abnormality With Uncommon Etiologies

Abstract

Introduction: Hypercalcemia is a relatively common electrolyte abnormality which is generally associated with Parathyroid related disorders or Cancers. Rare aetiologies comprise of granulomatous disorders and haematological malignancies namely Sarcoidosis and Lymphoma. Parathyroid hormone related Peptide (PTH-rp) and Calcitriol are implicated in causing Hypercalcemia in mentioned aetiologies. Case Details: A 57 year gentleman was admitted following a 10 day history of feeling unwell, unsteadiness in gait, constipation and mild shortness of breath (SOB) on walking uphill. His medical history comprised of Type 1 Diabetes Mellitus (DM) and Hypertension (HTN). Regular medications did not comprise of any drugs that could lead to Hypercalcemia. Biochemic he was Hypercalcemic at 3.14 (2.20–2.60). Parathyroid Hormone levels (PTH) was 0.6 (1.1–4.7 pmol/l) which excluded Parathyroid driven aetiologies. ACE levels were normal and Myeloma screen was negative. 25-OH Vitamin D levels were within Normal limits. Management: Hypercalcemia was managed with Intravenous Fluids and optimum hydration which improved his Calcium levels, followed by subsequent normalisation. Given his suppressed PTH levels, he underwent whole body imaging to assess for evidence of underlying occult malignancy. The CT imaging of his chest, abdomen and pelvis revealed widespread Lymphadenopathy and hypodense lesions in the Spleen. The report stated likely Sarcoidosis accompanied by Splenic involvement, with the main differentials being Sarcoidois versus Lymphoproliferative disorder. This was discussed with the respiratory team and Steroids were not commenced taking into account the improvement in his Calcium levels following adequate hydration and fluids. The patient has been kept under close follow up with ongoing monitoring of his clinical status. Summary: Hypercalcemia has been described in patients with Granulomatous disorders and Haematological malignancies. The incidence of hypercalcemia in Sarcoidosis is estimated to be approximately 10%, with no association with a specific demographic. Granulomatous disorders and Haematological malignancies constitute the rare aetiologies of hypercalcemia and are characterised by a low-normal or suppressed PTH level. Diagnosis of Sarcoidosis is often challenging with the lack of gold standard tests. Serum ACE levels can be within normal limits in people with Sarcoidosis despite not being on Steroid therapy. Evaluation of serum PTH-rp and Calcitriol can aid in diagnosis and more importantly assisting in prognostication, thus guiding further management.