Needle aspiration biopsy in cystic papillary carcinoma of the thyroid.

The records of 11 patients with cystic papillary carcinoma of the thyroid who had undergone preoperative sonography and fine-needle aspiration biopsy were retrospectively reviewed. The lesions varied from 1.5 to 5 cm in diameter. In only six (55%) of the 11 patients was the correct diagnosis made preoperatively. In the other 45%, the lesion was initially misdiagnosed as a benign or hemorrhagic cyst. These data indicate that needle aspiration often yields false-negative results in patients with cystic papillary carcinoma. All patients diagnosed on sonography and fine-needle aspiration as having benign cysts should have continued clinical follow-up. If lesions do not disappear either clinically or by sonography, a more aggressive approach should be taken.