¹⁸F-Choline PET/CT Sheds Light on a Parathyroid Adenoma - A First in the Philippines: A Case Report

The parathyroid glands play a crucial role in calcium regulation through parathyroid hormone (PTH) production. Indicators for those with hyperparathyroidism would be elevated serum calcium and PTH levels with further evaluation followed by imaging with neck ultrasonography and parathyroid scintigraphy. Limitations in the initial imaging modalities include operator-dependent sensitivity in neck ultrasonography, and poor spatial resolution, and poor sensitivity for smaller-sized adenomas in parathyroid scintigraphy. This case report describes a 24-year-old female with elevated parathyroid hormone, and borderline elevated calcium levels with an initial diagnosis of primary hyperparathyroidism secondary to a suspected parathyroid adenoma. The dual tracer dual-phase scintigraphy accompanied by SPECT/CT and subtraction method was negative for a parathyroid adenoma, however, ultrasonography of the neck showed a suspicious nodular structure. Due to the high clinical suspicion, a subsequent ¹⁸F-Choline PET/CT was done and identified an ¹⁸F-Choline-avid lesion, highly suggestive of a parathyroid adenoma. This prompted parathyroidectomy in which histopathology as well as intraoperative reduction in parathyroid hormone levels, confirmed the presence of a parathyroid adenoma. This is the first recorded ¹⁸F-Choline PET/CT usage for a parathyroid adenoma in the country and highlights the potential of its usage as a sensitive and specific imaging modality in cases where conventional imaging is inconclusive.