The Fallen One: The Inferior Parathyroid Gland That Descends Into the Mediastinum

Background: Inferior parathyroid glands are located along the embryologic migration path of the thymus and can rest in the thyrothymic ligament or anterior mediastinum. Our nomenclature system designates these glands as "fallen" (type F) glands. This study reviews our experience with type F parathyroid glands to determine which can be retrieved successfully through a cervical incision. Study Design: A retrospective review of patients who underwent parathyroidectomy between June 1998 and May 2008 was performed. Patient demographics, localization studies, and operative and pathologic reports were analyzed. Distance from the superior aspect of the clavicle to the target parathyroid gland was measured. Results: Sixty (9.2%) patients had a type F parathyroid gland. Parathyroidectomy was performed through cervical incision in 54 (90%) patients and 6 (10%) required a thoracic approach. Preoperative imaging identified parathyroid glands located ≥6 cm below the superior aspect of the clavicle in eight patients. Of these, six (75%) required a thoracic approach and two (25%) were resected through a cervical incision with concomitant thymectomy. Parathyroidectomy was successfully performed through a cervical incision in all 52 (100%) patients in whom the target parathyroid gland was <6 cm below the superior aspect of the clavicle (Fisher's exact test, p < 0.001). Conclusions: A cervical approach allows successful retrieval of type F parathyroid glands located <6 cm below the superior aspect of the head of the clavicle in the anterior mediastinum. Parathyroidectomy for glands located ≥6 cm below the superior aspect of the clavicle can be attempted from the neck with concomitant thymectomy, but the majority will require a thoracic approach.