Ectopic parathyroid adenoma as a cause of persistent primary hyperparathyroidism (case report)

Persistent primary hyperparathyroidism (PHPT) following parathyroidectomy is most often caused by ectopia of a pathologically altered parathyroid gland (PTG). This condition makes accurate preoperative topographic diagnosis critically important, especially in repeat interventions, which themselves are associated with an increased risk of complications due to scar tissue formation and difficulties in anatomical identification. In the presented clinical case, a 70-year-old patient had persistent biochemical signs of PHPT after the initial surgery. During that intervention, a lesion identified on imaging as a PTG adenoma was removed, but postoperative histology unexpectedly revealed papillary thyroid cancer. This diagnostic dilemma clearly illustrates the morphological similarity of various neck lesions during intraoperative examination and underscores the value of intraoperative histological examination in ambiguous situations. To identify the cause of disease persistence, a comprehensive examination was performed. Repeat scintigraphy with SPECT/CT and multispiral computed tomography (MSCT) allowed for precise localization of the pathological focus. An ectopic adenoma of the right inferior PTG with aberrant migration, corresponding to Type C according to the Perrier classification, was diagnosed and subsequently successfully removed. This case confirms the necessity of a multidisciplinary approach and high oncological vigilance in managing patients with PHPT. It also demonstrates the practical utility of PTG ectopia classifications, which not only systematize anatomical location but also help the surgeon predict the technical complexity of the upcoming intervention, potential risks, and choose the optimal surgical approach.

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