Preoperative Assessment of Thyroid Nodules: Role of Ultrasonography and Fine Needle Aspiration Biopsy Followed by Cytology

Abstract

Camargo RYA, Tomimori EK, Knobel M, Medeiros-Neto G. Pre-operative assessment of Thyroid nodules: respective roles of ultra-sonography, fine needle aspiration biopsy followed by cytology. CLINICS. 2007;62(4):411-8. PURPOSE:To evaluate the preoperative assessment of thyroid nodules using ultrasound studies and cytology of nodular aspirates. SUBJECTS AND METHODS: 2,468 patients with thyroid nodules were examined from 1999 to 2005. All patients were clinically examined and underwent ultrasonography followed by fine-needle aspiration biopsy (FNAB) and cytology. RESULTS:Nodules larger than 10 mm were classified ultrasonographically in a 4-tier system and received a score according to the criterion of possible malignancy. Cytological examinations were conducted independently by 2 cytologists and classified as benign (score 1), indeterminate (score 2), suspicious (score 3), and malignant (score 6). Combining both scores, an index was generated that would indicate a higher probability of malignancy (benign, doubtful, suspicious, and malignant). Thyroid surgery was performed in 274 patients. Of those, 115 patients had a score of 2 to 5 and only 8 had a histological diagnosis of thyroid cancer (6.9%). For patients with a score of 5 (n = 51), 11.5% had a malignant lesion, and 51% of the 61 patients with a score of 6 had confirmed thyroid cancer. Of the 98 patients with a combined score of 7 to 10, 99% had a histological confirmation of malignancy. CONCLUSIONS: The index score had a sensitivity of 94.1% and specificity of 77.5%. The overall accuracy was 85.8%. Therefore, we concluded that this methodology may improve the preoperative diagnosis of thyroid cancer in nodules larger than 10 mm. Association with other methods such as color Doppler echography, serum TSH concentration, galectin-3 expression analysis, and FDG/PET scan would be useful in avoiding the higher costs of thyroid surgical procedures.

Ultrasonographic characteristics as a criterion for repeat cytology in benign thyroid nodules

“…However, only seven cases of malignancy were detected in that study and surprisingly only 4% in the second group presented these characteristics (9). In the present study using characteristics of high specificity (17)(18)(19)(20), although only 11.4% of the nodules presented these findings, the chance of malignancy in a second FNAC exam was approximately 17%. Although the FNAC was not repeated in the case of non-suspicious nodules considering this proportion of suspicious nodules, the frequency of malignancy in this group and an overall malignancy rate of approximately 2% upon repeat FNAC (3,4,6-9) it was concluded that specifically in these cases (non-suspicious nodules) malignancy should be negligible.…”

“…Although this imaging method alone does not define the etiology of the nodule it assists in the differentiation between benign and malignant nodules (10,(17)(18)(19)(20). This fact renders ultrasonography a highly attractive tool for the selection of candidates for repeat FNAC in the case of an initial benign cytological diagnosis, but its validation for this purpose is fundamental.…”

Etiopathology, clinical features, and treatment of diffuse and multinodular nontoxic goiters

“…Routine assessment of the thyroid with ultrasonography (in association with the analysis of the vascularization with color Doppler) had a great impact in endocrinology practice [47]. This methodology is widely disseminated due to the greater availability of high-resolution equipment, relatively affordable devices, little or no discomfort for the patient, and the absence of ionizing radiation.…”

Comparação das classificações dos nódulos de tireoide ao Doppler colorido descritas por Lagalla e Chammas

“…É frequente, na literatura, o relato de nódulos malignos pouco vascularizados, bem como de nódulos benignos hipervascularizados (8,16,19,21,22). Embora, neste estudo, tenha sido demonstrado risco maior de malignidade na presença de vascularização central predominante nos nódulos de tireoide, a ausência de fluxo central não indica com segurança benignidade, pois uma proporção significativa de carcinomas papilares apresentou tal característica (Figuras 3 e 4).…”