Retropharyngeal Ectopic Parathyroid Gland Presenting as Primary Hyperparathyroidism: A Diagnostic Challenge From the...

Ectopic parathyroid tissue is an unusual yet clinically significant contributor of primary hyperparathyroidism (PHPT), especially when standard localization studies yield inconclusive results. Retropharyngeal ectopic parathyroid glands are uncommon and may postpone diagnosis due to their unusual anatomical location. This report details a case of a 39-year-old woman exhibiting hypercalcemia, musculoskeletal pain, constipation, a history of nephrolithiasis, and diminished bone mineral density. Biochemistry showed that parathyroid hormone (PTH) levels were always high, with occasional hypercalcemia and hypercalciuria, which is what you would expect with PHPT. Ultrasound of the neck did not show a parathyroid lesion. Cross-sectional imaging and fluorocholine PET/CT identified a retropharyngeal soft tissue nodule indicative of ectopic parathyroid tissue. Histopathology following biopsy confirmed parathyroid tissue. This case highlights the endocrine diagnostic pathway in PHPT, the importance of correlating biochemical findings with advanced imaging, and the need to consider ectopic glands when first-line imaging is negative.