Clinical presentation: A 71-year-old woman was referred for aspiration cytology because of a nodular goiter disclosed on a carotid Doppler examination.

Ultrasonography revealed a deeply hypoechogenic lesion dorsal to the upper pole of the lower part of the left thyroid.

Cytology: a benign lesion.

Combined sonographic-cytologic diagnosis possible parathyroid adenoma.

Scintigraphy disclosed a parathyroid enlargement in this localization, while serum-calcium and parathormone levels were elevated.

Histopathology: a solitary parathyroid adenoma.

Comment.

1. This is one of our few cases of a hyperfunctioning parathyroid adenoma causing hypercalcemia in which the evaluation process was initiated by ultrasonography.

2. The lesion should be classified as a TIRADS 5 lesion because of the deep hypoechogenicity.