Clinical presentation: A 42-yr-old woman was referred for further evaluation of a thyroid nodule. Initially, a low TSH level (0.07 mIU/L) was detected by chance. Scintigraphy disclosed an increased uptake in the left lobe.

Palpation: no abnormality.

Laboratory test: TSH 0.89 mIU/L, FT4 11.0 pM/L, FT3 4.91 pM/L, TSAb undetectable, aTPO 0.5 U/mL.

Ultrasonography. The thyroid was echonormal. There was a hypoechogenic nodule presenting irregular, spiculated and lobulated margins.

Cytology was performed and resulted in oxyphilic tumor.

Histopathology disclosed an oxyphilic variant of papillary carcinoma.

Comment. Although the scintigraphy disclosed autonomously functioning adenoma, on the ultrasound pattern the lesion was regarded suspicious.