Thyroid nodules with highly suspicious ultrasonographic features, but with benign cytology on two occasions: is malignancy still possible?

Abstract

Objective: There is no information about the frequency of malignancy specifically in the case of thyroid nodules with highly suspicious sonographic features, but with two fine needle aspiration (FNA) showing benign cytology. This was the objective of the study. Subjects and methods: We report the results of 105 patients with thyroid nodules considered "highly suspicious" according to the ultrasonographic classification of American Thyroid Association, in whom FNA revealed benign cytology on two occasions (interval of 6 months). Results: Thyroidectomy was performed in 11 cases due to desire of the patient or significant growth of the nodule. In these patients, cytology continued to be benign in 9, was non-diagnostic in 1, and suspicious in 1. Histology revealed papillary carcinoma in only one nodule. In patients in whom a third FNA was obtained for this study (n = 94), cytology continued to be benign in 86, became non-diagnostic in 5, indeterminate in 2, and suspicious in 1. The last 8 patients (with non-benign cytology) were submitted to thyroidectomy and histology revealed malignancy in only one nodule. Conclusion: The rate of malignancy found here for nodules with highly suspicious sonographic features, even after two FNA showing benign cytology, was 2%. We believe that in these cases, the continuation of follow-up consisting of ultrasound at intervals of 2 years may still be adequate. Arch Endocrinol Metab. 2016;60(4):402-4

Is fine needle aspiration really not necessary in patients with thyroid nodules ≤ 1 cm with highly suspicious features on ultrasonography and candidates for active surveillance?

“…Since the ATA recommendation is general, there is more reason that it applies to nodules ≤ 1 cm. Indeed, in this situation (benign on two occasions), histology or a third FNA did not detect malignancy in any of the 28 nodules ≤ 1 cm in our series, and even among highly suspicious nodules > 1 cm we found malignancy in < 2% of cases . In addition to this relevant difference in follow‐up, with the omission of FNA, a significant proportion of patients (about 30% in the present series) would be unnecessarily and equivocally submitted to the psychological stress of having a presumptive diagnosis of “cancer” or of a “nodule with a high probability of cancer”.…”

Ultrasound Classification of Thyroid Nodules: A Systematic Review

“…Five comparatively small studies included 238 participants (272 nodules), 105 participants (nodules not reported), 100 participants (157 nodules), 100 participants (nodules not reported), and 84 participants (87 nodules) [17-19, 22,23]. A total of 9,010 participants (10,611 nodules) were reported from all studies [14][15][16][17][18][19][20][21][22][23][24][25]. The proportion of participants who were male (nodules from male participants) reported from studies ranged from 14% to 33% (20-29%) [15][16][17][18][19]22,23].…”

“…A total of 9,010 participants (10,611 nodules) were reported from all studies [14][15][16][17][18][19][20][21][22][23][24][25]. The proportion of participants who were male (nodules from male participants) reported from studies ranged from 14% to 33% (20-29%) [15][16][17][18][19]22,23]. The mean age of all participants was relatively consistent and reported to be 46-59 years [15,16,[18][19][20]23].…”

“…The proportion of participants who were male (nodules from male participants) reported from studies ranged from 14% to 33% (20-29%) [15][16][17][18][19]22,23]. The mean age of all participants was relatively consistent and reported to be 46-59 years [15,16,[18][19][20]23]. One study reported the mean age only for participants with benign and malignant nodules: 42 and 43 years, respectively [17].…”

“…One study reported the mean age only for participants with benign and malignant nodules: 42 and 43 years, respectively [17]. Another study reported the median age for all participants (46 years) [18]. By comparison, the reported age range varied to a greater extent, with a lower limit of 16-34 years and an upper limit of 78-97 [15,16,18,20,23].…”