Category: Calcium/Bone Disorders

Monitor: 6

6 - A PARATHYROID ADENOMA IN THE STERNOHYOID MUSCLE

Thursday, Apr 25
12:00 PM – 12:30 PM

Objective :

Parathyroid auto-transplantation in the neck muscles is commonly practiced by surgeons to prevent post-operative hypoparathyroidism in the setting of total thyroidectomy. We present a rare case of a patient with a history of total thyroidectomy and auto-transplanted parathyroid glands into the sternohyoid muscle who developed primary hyperparathyroidism from a parathyroid adenoma arising from this auto-transplanted tissue.



Case Presentation: 
A 71-year-old woman with a history of papillary thyroid cancer underwent an uneventful total thyroidectomy 18 years ago. During the surgery, she had 2 parathyroid glands auto-transplanted into the left infrahyoid (strap) muscles. She has since been cancer-free. She later presented with biochemical findings consistent with primary hyperparathyroidism with normal renal function. Computed tomography scan of the neck demonstrated a hyper-enhancing lesion within the left infrahyoid muscles, which correlated with parathyroid sestamibi scan that revealed increased radiotracer activity within the lesion. This was indeed confirmed intraoperatively as there was a palpable nodule within the left sternohyoid muscle that was easily wedged out. Intraoperative intact parathyroid hormone level appropriately declined from 84 pg/mL to 12 pg/mL. Pathological analysis confirmed an irregular lobulated tan-red hypercellular parathyroid tissue measuring 1.5 x 1.2 x 0.6 cm and weighing 0.772g. Intact parathyroid hormone and calcium levels normalized after surgery.


Methods : n/a


Results : n/a


Discussion :

Auto-transplantation of parathyroid tissue is an established practice after total thyroidectomy. Without parathyroid tissue, regulation of calcium is affected and hypocalcemia can ensue.  To circumvent this problem, parathyroid glands are excised and transplanted commonly into strap muscle to prevent permanent hypoparathyroidism. A rare complication from this practice is progression of parathyroid tissue into parathyroid adenoma producing primary hyperparathyroidism as illustrated in this case.  


Conclusion :

Parathyroid tissue auto-transplanted into neck muscle can rarely progress to parathyroid adenomas. Patients with a history of total thyroidectomy who subsequently develop primary hyperparathyroidism can have this unique etiology included in the differential.

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Mohsinah Usmani

Endocrinology Fellow
Albany Medical Center

Endocrinology Fellow at Albany Medical Center

Todd Beyer

Associate Professor
Albany Medical Center

Associate Professor at Albany Medical Center
Program Director, General Surgery Residency
Breast and Endocrine Surgery

Hassan Shawa

Assistant Professor
Albany Medical Center

Assistant Professor in Endocrinology at Albany Medical Center