Clinical data: A 65-year-old woman was referred for an evaluation of a nodule discovered on carotid Doppler examination.

Palpation: no abnormality.

Functional state: euthyroidism with TSH 0.72 mIU/L.

Ultrasonography: There was a hypoechogenic lesion in the dorsal part of the thyroid with a combined type 2 and type 3 vascular pattern.

Cytology diagnosis: oxyphilic tumor.

Additional laboratory investigations disclosed hypercalcemia (serum-calcium 2,75 mM/l, serum-phosphorus 0,77 mM/L). Parathormone was determined and resulted in elevated level: 107 pg/mL (normal value: 15-68).

Histopathology: oxyphilic adenoma corresponding to the right lower parathyroid.

Comments:

1. The location of the lesion had to raise the possibility of parathyroid origin of the lesion.

2. The cytological pattern is identical to an oxyphilic tumor of the thyroid.