Fortuitous discovery of non-fluorocholine-fixing papillary carcinoma of vesicular variant of the thyroid.

PURPOSE: Characterization of thyroid nodules is crucial to propose surgical intervention for histological verification. Cervical ultrasound potentially combined with fine needle aspiration is recommended, and fluorocholine positron emission tomography (FCH-PET), commonly used in prostatic cancers, has been evaluated in the diagnosis of thyroid cancers in recent publications.

METHODS: We present two cases of patients with multinodular thyroid and primary hyperparathyroidism. The preoperative assessment consisted of an ultrasound, a MIBI scintigraphy and an FCH-PET in favor of a parathyroid adenoma.

RESULTS: The imaging examinations pointed to a diagnosis of a parathyroid adenoma. In both cases, papillary thyroid carcinoma, missed by FCH-PET, was discovered incidentally at a distance from the parathyroid adenoma during the surgical procedure.

CONCLUSIONS: These are the first descriptions of thyroid papillary carcinoma without preoperative FCH-PET identification. These clinical cases are contrary to recent publications showing a benefit of this examination in the diagnosis of thyroid cancers.