engleski

Solitary isoechogenic thyroid nodule - nodular goiter or follicular tumor ?

Thyroid tumors are often present as a hypoechogenic nodule. But in some cases follicular adenomas can be present as isoechogenic nodules like nodular goiters. The aim was to investigate whether it is possible on the basis of ultrasound images and vascularization of a tumor to distinguish thyroid tumors from benign goiter. We examined 87 patients with solitary isoechogenic thyroid nodules, mean age 51 yrs. 77 female, and 10 male. All were examined with conventional B-mode and Color/Power Doppler. Tc 99m scintigraphy, hormonal status, and FNAB were done. Patients with a cytological diagnosis of folicular tumors were treated by surgery. Of the 87 isoechogenic nodes, 39 were confirmed with folicular adenoma, two with folicular carcinoma, one with papillary carcinoma, 11 with Hashimoto thyroiditis, 30 with nodular goiter and four with toxic adenoma. The average volume of folicular adenoma (6.1 ml) was greater by half than the average volume of nodular goiter (3.25) and HT (3.13), but it was not statistically significant (t = 1.74) n.s.). Hypoechogenic rim was present in all folicular adenomas, although in 23 percent it was very discreet, and in 80 percent of the nodular goiter, 23 percent were very discreet. In one folicular carcinoma the rim was not clearly visible. All folicular adenomas had vascularized capsules, 63 percent of the nodes showed internal vascularization, which was found in only 27 percent of the nodes in the nodular goiter. In all three carcinoma calcification was found in the nodes, and in 20 percent of the adenoma and in 20 percent of the goiter, while it was not found in the Hashimoto thyroiditis. Scintigraphically, a "cold" nodule was observed in 59 percent of the patients, a „ hot“ nodule in five patients, but in 34 percent of the patients the nodule was not clearly seen on the scintigram, most frequently because of the small dimensions or the dorsal location. The patients were euthyroid in 92 percent of the cases, hypothyroid in 4 percent and hyperthyroid in 4 percent. The best results in differentiating folicular tumors from benign goiter were obtained with the help of FNAB (sensitivity 94, 3, specificity 94, 1 %, and predictive positive value 96, 1%) Although there is a difference in echographic appearance and vascularity (internal and peripheral flow) between folicular tumors and nodular goiters, there is no statistical significance. For a preoperative diagnosis FNAB, which best agrees with PHD finding, is necessary.

thyroid nodule; ultrasonography; color doppler

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