Integrated 18 F-FCH PET/4D-CT in a Case of Supernumerary Parathyroid Glandular Hyperplasia With Incidentally Detected Thymic NET.

Less than 10% of primary hyperparathyroidism (PHPT) patients have supernumerary parathyroid glands. In a 52-year-old man with multiple endocrine neoplasia type 1 (MEN 1) syndrome with PHPT, integrated 18 F-Fluorocholine PET/4D-CT (FCH PET/4D-CT) was done for localization of parathyroid adenoma. FCH PET/4D-CT revealed 5 culprit lesions (1 ectopic) along with FCH avid nonenhancing anterior mediastinal mass, possibly NET or thymoma. FNAC of the mass raised a suspicion of NET, which was corroborated by subsequent 68 Ga-DOTANOC PET/CT. Parathyroidectomy for all 5 glands and thymic mass excision was done. Histopathology confirmed 5 hyperplastic parathyroid lesions and a well-differentiated thymic NET. Intact PTH and calcium levels were normalized postsurgery.