Ectopic parathyroid adenoma located inside the hypoglossal nerve.

Abstract

Intraneural parathyroid adenomas are extremely rare, with only 9 cases of intravagal adenomas reported. We report the first case of an ectopic parathyroid adenoma located within the hypoglossal nerve. A 62-year-old woman presented with a palpable nodule in the right submandibular area, reduced bone mass, and elevated calcium and parathormone levels. Preoperative investigation with neck ultrasound and MRI did not provide a definitive diagnosis, whereas sestamibi scan showed slightly increased radiotracer accumulation in the same area. Intraoperatively, the right hypoglossal nerve was found to course through the lesion and, despite the attempt to salvage it, most of its fibers were transected. Histopathology confirmed the presence of a parathyroid adenoma inside the trunk of a nerve. Postoperatively, calcium and parathormone levels decreased but right hypoglossal nerve paresis was noted. This unique case emphasizes the variability of parathyroid anatomy and the difficulties faced by the surgeon when treating this disease process.