Synchronous Metastatic Medullary Thyroid Carcinoma and Paraesophageal Parathyroid Adenoma Detected on 18F-Ethylcholine PET/US Fusion Imaging

An 80-year-old woman with osteoporosis without fractures was referred with asymptomatic primary hyperparathyroidism and elevated calcitonin level. Ultrasound, Tc-99m-pertechnetate scintigraphy, Tc-99m-MIBI scintigraphy, and CT revealed a suspicious thyroid nodule and enlarged submandibular lymph nodes. However, no parathyroid adenoma was depictable. F-18-choline PET/CT showed increased uptake of the proximal esophagus, but neither CT nor US revealed a parathyroid lesion, and only F-18-choline PET/US fusion imaging confirmed a paraesophageal parathyroid adenoma. Resection of both medullary thyroid carcinoma and ectopic parathyroid adenoma through a single cervicotomy was conducted (thyroidectomy, neck dissection, extirpation of parathyroid adenoma); parathyroid hormone and calcitonin dropped to normal. Multiple endocrine neoplasia IIa syndrome was suspected.

Automated summary

This article reports a case of an 80-year-old woman with osteoporosis without fractures, asymptomatic primary hyperparathyroidism, and elevated calcitonin level. Various imaging modalities revealed a suspicious thyroid nodule and enlarged submandibular lymph nodes, which were ultimately confirmed to be a paraesophageal parathyroid adenoma. The patient underwent thyroidectomy and parathyroid adenoma excision, leading to the normalization of parathyroid hormone and calcitonin levels. Multiple endocrine neoplasia IIa syndrome was suspected.