PG, when located at the base of cranium/neck, are rarely functioning and usually discovered due to mass effect. 2 patients underwent surgery for neck enlargement at our center in 2021 and 2023.

M.C.(F,74y), asymptomatic, underwent neck US that showed hypoechogenic, vascularized, 5cm palpable mass in the right thyroid bed, but not mobile during deglutition, this excluding thyroid origin. Chromogranine positivity was found at FNA, so DOPA-PET/TC was requested (positive), and angioTC confirmed the position behind the innominate trunk. C.M.(F,74y), affected by old goiter, was evaluated for mass effect. US showed multiple thyroidal nodules, the biggest in the right lobe (5cm), plongeant, with tracheal displacement and benign citology (Tir2). TC scan confirmed the nodular goiter.

In June 2021, M.C. underwent resection of a highly vascularized mass adjacent to the main cervical axis; the histopathological examination confirmed a carotid sinus PG. In May 2023, C.M. underwent surgery for total thyroidectomy: surprisingly, the main right thyroidal nodule turned out to be an hypervascular extrathyroidal mass, tenaciously sticking to the common carotid, jugular vein and vagus nerve, suspicious for PG, that was resected along with homolateral thyroid lobectomy. PG was confirmed only at postsurgery histopathology.

Neck enlargements can be sometimes misdiagnosed with goiter. In the first case, cervical palpation, highlighting a non-mobile nodule, raised the suspicion for an extrathyroidal mass, leading to in-deep investigations. In the second case, the plongeant mass could not be physically examined and the repetitive exams demonstrating thyroidal goiter leaded to an intraoperative, unexpected diagnosis.