Clinical data: a 40-year-old woman was referred for evaluation of a nodule detected by the patient herself. Aspiration cytology resulted in AUS-FLUS (Bethesda) in another institute.

Palpation: a not firm lesion in the lower-lateral part of the right thyroid bed.

Laboratory test: TSH 2.40 mIU/L.

Ultrasonography: the thyroids were echonormal and intact. There was a cystic-minimally hypoechogenic mass lateral and lower to the right thyroid. The vascularization was not specific.

We aspirated the lesion for cytological examination and determination of thyroglobulin and parathormone levels. Aspiration cytology resulted in benign lesion corresponding to a parathyroid lesion.

Wash-out was thyroglobulin was extremely low (0.08 mg/L), while wash-out parathormone resulted in an extremely high level 3248 pg/mL.

Serum parathormone level turned to be normal (39.9 pg/mL (normal value: 15-66) as did calcium (2.32 mM/L) and phosphorus (1.06 mM/L).

Surgery was performed. Histopathology disclosed parathyroid adenoma.

Comments.

1. The location of the enlarged parathyroid was unusual. Nevertheless, it was unequivocally outside the thyroid. This fact has to be considered in the analysis of cytological pattern.

2. There is no specific cytological sign of a parathyroid lesion. The pattern is identical with a normofollicular adenoma with signs of hormonal influence.