CASE PRESENTATION: A 79 year old female with a distant history of breast cancer presented with altered mental status. Patient was alert but nonverbal and was unable to follow commands. Family at bedside denied any other symptoms and also informed that she was diagnosed with dementia 6 months prior, with a rapid cognitive decline within the last 2 weeks. Initial physical exam was remarkable for hypotension, tachycardia, and epigastric tenderness. Labs were significant for lactate of 4.7, leukocytosis of 35K, lipase of 5372, calcium of 21mg/dL, pyuria, and BUN/Cr elevated from her baseline of 8mg/dL and 0.81 mg/dL, to 81mg/dL and 4.31mg/dL respectively. CT of the head was within normal limits. Hemodynamic stability was obtained after initial treatment for sepsis and pancreatitis. However she was admitted to the ICU for concerns of airway protection due to her severely depressed mentation. Renal function was only marginally improving at this point, and a decision was made to dialyze her for better improvement of her persistently elevated calcium level. Pamidronate and Calcitonin were also administered per endocrinology team recommendation. Concurrent workup revealed elevated serum PTH levels, and a CT scan of the neck showed a parathyroid mass. This was later localized with a sestamibi scan and she subsequently had a parathyroidectomy, which pathology revealed an adenoma. She was discharged shortly afterwards with her mental status at baseline and a normal calcium level.