Recurrent Primary Hyperparathyroidism after Autotransplantation of an Excised Parathyroid Adenoma

Introduction: We present a patient with recurrent primary hyperparathyroidism after reimplantation of a portion of an excised parathyroid adenoma. To our knowledge, there has been only one other case reported in the literature describing a re-implanted parathyroid adenoma as the culprit for recurrent primary hyperparathyroidism. Case Description: A 65-year-old female presented with recurrent primary hyperparathyroidism. She had undergone a left superior parathyroidectomy for hyperparathyroidism eight years ago and previously had undergone a total thyroidectomy. The intraoperative intact parathyroid hormone (iPTH) level at the time of her arathyroidectomy reportedly dropped from a baseline of 93.8 pg/mL to 11.7 pg/mL at twenty minutes post-excision. Due to concern for a lack of functioning parathyroid tissue on the contralateral side, a portion of the excised gland was re-implanted into the left sternocleidomastoid (SCM) muscle. Over the following seven years, her bone density declined to osteoporosis, and she was found to have an elevated serum calcium level of 10.8 mg/dL (reference: 8.6 mg/dL to 10.4 mg/dL) as well as an elevated iPTH level of 79 pg/mL (reference: 10 pg/mL to 65 pg/mL). Urinary calcium was additionally elevated at 273 mg/24 h (reference: 35 mg/24 h to 250 mg/24 h). A CT scan of the neck demonstrated a 2 cm left-sided mass within the inferior portion of the left SCM. The patient therefore underwent a re-operative neck exploration. Baseline iPTH was 75 pg/mL. Intra-operative findings revealed abnormal parathyroid tissue within the left SCM muscle. Post-excision iPTH level was 47 pg/mL. The surgical pathology demonstrated a 2.4 cm mass composed of hyper-cellular parathyroid tissue and skeletal muscle. Justin Yozawitz*, Rasa Zarnegar and Thomas J Fahey Department of Endocrine Surgery, New York Presbyterian Hospital, Weill Cornell Medical College, New York, USA