SUN-494 Multiple Ectopic Parathyroid Foci: An Unexpected Finding Leading to Primary Hyperparathyroidism

Background: A patient with severe hypercalcemia and extremely elevated PTH levels found to have multiple foci of ectopic parathyroid tissue. Clinical Case: A 60-year-old female with a history of hypothyroidism and hypertension was transferred from another facility for evaluation for a parathyroidectomy. Vital signs were within normal limits. Initial evaluation revealed a corrected calcium of 8.2 mg/d, albumin level of 2.4 g/dL (n 3.2 - 4.6 g/dL). Creatinine was within normal limits. PTH level of 908 pg/dL (n 9.0 - 77.0 pg/dL), 25-vitamin D level of 15 ng/mL. The patient was recently admitted to another facility for septic shock secondary to UTI. She was found to have bilateral renal stones, for which she underwent ureteral stent placement. Further workup revealed severe hypercalcemia of 20.0 mg/dL and a PTH level >2,500 pg/dL. She was treated with IV fluids, bisphosphonates, calcitonin and cacimimetics. She was discharged with the plan for an outpatient parathyroidectomy. Prior to the parathyroidectomy, the patient was readmitted for acute respiratory failure. A parathyroid NM scan was performed and revealed no persistent uptake to suggest a parathyroid adenoma. She was subsequently transferred and admitted to our facility.During the admission, ENT and endocrinology were consulted. A NM scan was repeated, which showed a questionable right lower pole thyroid focus concerning for a parathyroid adenoma. 4D CT scan had concordant findings. Due to the exceedingly elevated PTH level, there was concern for parathyroid carcinoma. Patient underwent right thyroid lobectomy, parathyroidectomy with four-gland exploration, right central neck dissection, and reimplantation of ½ left super parathyroid to the left sternocleidomastoid. After the surgery, calcium and vitamin D supplementation were initiated. Her calcium levels remained stable throughout the hospital course. Operative parathyroid pathology revealed normal parathyroid glands with no malignancy, in addition to 12 foci of ectopic parathyroid glands. Conclusion: Treatment of primary hyperparathyroidism with parathyroidectomy is efficacious in 80-97% of initial explorations. The ability to locate ectopic glands are linked to the failure or success rates. Although ectopic parathyroid glands are common (15%), multiple ectopic glands, as in this case, are rarely reported. References: Am Surg. 2000 Nov;66(11):1028-31, BMJ Case Reports 2017; doi:10.1136/bcr-2017-221130