Three Different Etiologies in Three Similar Looking Intrathyroidal Nodules: Role of Tc-99m SestaMIBI Scintigraphy and SPECT-CT in a Patient With Primary Hyperparathyroidism.

A 46-year-old woman with hypercalcemic primary hyperparathyroidism underwent a Tc-99m SestaMIBI scintigraphy and SPECT-CT, which identified 3 distinct radiotracer-avid intrathyroidal nodules. Following a right hemithyroidectomy and subsequent histopathologic evaluation, it turned out that she had 3 pathologically distinct nodules, that is, intrathyroidal parathyroid adenoma, invasive encapsulated follicular variant of papillary thyroid carcinoma, and tall-cell variant of papillary thyroid microcarcinoma. Our case serves as an important reminder that at times even distinct pathologies can present with identical anatomic features and radiotracer uptake patterns.