Fate of untreated benign thyroid nodules: Results of long‐term follow‐up

Abstract

The fate of benign thyroid nodules has been unknown because there has been no study in this regard. We re-examined 134 patients with thyroid nodules who had had benign aspiration biopsy cytology 9 to 11 years ago. The thyroid gland was palpated by the same two thyroidologists throughout the study. Ultrasonography, fine-needle aspiration biopsy (FNAB), and ultrasound-guided FNAB were employed to examine the nature of nodules of 9 to 11 years' duration. Patients (n = 61) who had nodules difficult to palpate (small nodules), multiple nodules, or cystic nodules with papillomatous proliferation underwent ultrasound-guided FNAB; patients (n = 55) having a distinctly palpable single nodule underwent usual FNAB. None of the patients received any medical or surgical treatment. There were 86 single nodules, 14 multiple nodules, and 34 cystic nodules on the first examination. These benign nodules were reexamined for changes in size and cytology 9 to 11 years later. The most striking finding was a decrease in size or disappearance of the nodule in 42% to 79% of benign nodules. About 92% of nodules remained benign without changing cytologic classification. Only one case (0.9%) previously regarded as benign turned out to be malignant; this nodule grew in size compared with the previous examination. Among single and multiple nodules, 21% to 23% of the nodules increased in size; however, most patients with enlarged nodules (86%) showed the same class 2 cytology as before. Our present study indicates that biopsy-proved benign thyroid nodules remain benign over a prolonged period. Thus no medical or surgical treatment is required so long as the nodules do not grow.

A study on the clinical manifestations and the incidence of benign and malignant tumors in a solitary thyroid nodule

“…This is consistent with other studies. [11][12][13][14] The current study is consistent with the previous study where the FNAC results of STNs showed that 65% of nodules were diagnosed as colloid goiter (n=98) followed by 12.6% cases as thyroiditis (n=19). 23 Surgical intervention is required for solitary thyroid nodules if there is any cytological suspicion or evidence of malignancy Therefore, all these subjects who were suspected with evidence of malignancy were subjected to definitive surgical intervention.…”

“…Previous studies indicate that 38% of these palpable lesions were observed to disappear completely with time. 10,11 However, various factors like age, sex, iodine deficiency and history of radiation exposure contribute to the formation of nodules. Previous history of ionizing radiation is associated with a risk of higher incidence of benign as well as malignant nodules of thyroid.…”

Collapsing Benign Cystic Nodules of the Thyroid Gland: Sonographic Differentiation from Papillary Thyroid Carcinoma

“…Several studies have assessed the natural history of thyroid nodules, 11,12 with 1 13 reporting that the most common outcome of benign thyroid nodules, untreated for an average of 15 years after the first examination, was a decrease in nodule size, including disappearance (52.9%), with a decrease in size being more prominent in cystic nodules. In contrast, others have reported that 39% of benign thyroid nodules increase in size during follow-up, with cystic nodules being more likely to maintain or decrease in size than solid nodules.…”

Benign cystic nodules may have ultrasonographic features mimicking papillary thyroid carcinoma during interval changes

“…Malignancymimicking features in benign cystic thyroid nodules with follow-up US after percutaneous ethanol injection or colloid aspiration have been reported [7,8]. About 80% of the benign cystic nodules decreased in size or disappeared when they were examined 9 to 11 years later [9]. It has not been reported whether benign cystic nodules have malignancy-mimicking features in US after simple percutaneous aspiration or during the natural course.…”