Ectopic parathyroid adenomas represent a diagnostic challenge, since they are Iuite rare in clinical practice.We present a case of a 61 years old man with symptomatic hypercalcemia due to an ectopic parathyroid adenoma in the upper-Anterior mediastinum that was not localized by the scintigraphy. Ultrasonography identified a nodule on the left upper-superior lobe of the thyroid gland, consistent with a parathyroid adenoma; scintigraphy showed two focuses of abnormal tracer uptake, one on the left upper-superior lobe of the gland and the other on the right inferior lobe of the gland. Patient underwent surgery to remove the adenoma on the left side, but postoperatively PTH and serum calcium level were still elevated. CT scan showed a mass of 27 x 22 mm in the upper anterior mediastinum, in front of the right emisoma of D2.The final surgery allowed us to remove the adenoma with a laterocervical approach. The histopathology was consistent with parathyroid adenoma
