18F-Fluorocholine PET/CT in the Detection of Hyperfunctioning Transplanted Parathyroid Tissue

Area of Science:

• Endocrinology
• Nuclear Medicine
• Surgical Oncology

Background:

• Multiple endocrine neoplasia type 1 (MEN1) is a genetic disorder predisposing individuals to tumors in endocrine glands.
• Primary hyperparathyroidism is a common manifestation of MEN1, often requiring surgical intervention.
• Parathyroid autotransplantation is a surgical technique used to preserve parathyroid tissue during parathyroidectomy.

Observation:

• A 54-year-old woman with MEN1 and hyperparathyroidism developed recurrent hypercalcemia years after parathyroid autotransplantation.
• Fluorine-18-fluorocholine positron emission tomography/computed tomography (18F-FCH PET/CT) was utilized to localize hyperfunctioning parathyroid tissue.
• The PET/CT scan successfully identified a hyperplastic parathyroid autograft in the right forearm.

Findings:

• The 18F-FCH PET/CT scan ruled out ectopic or orthotopic recurrent parathyroid adenomas.
• A hyperplastic parathyroid tissue fragment in the forearm was confirmed as the source of persistent hypercalcemia.
• Cinacalcet therapy was initiated for managing hypercalcemia prior to definitive localization.

Implications:

• 18F-FCH PET/CT is a valuable tool for localizing hyperfunctioning parathyroid tissue, even in ectopic or grafted sites.
• Accurate localization is crucial for guiding surgical or therapeutic interventions in recurrent hyperparathyroidism.
• This case highlights the potential for autotransplanted parathyroid tissue to become hyperplastic and cause persistent disease.