Comparison of palpation-guided versus ultrasound-guided fine-needle aspiration biopsies of thyroid nodules in an outpatient endocrinology practice.
Author(s): Izquierdo R, Arekat MR, Knudson PE, Kartun KF, Khurana K, Kort K, Numann PJ
Publication: Endocr Pract, 2006, Vol. 12, Page 609-14
PubMed ID: 17229656 PubMed Review Paper? No
Purpose of Paper
This paper compared the cytological diagnosis of ultrasound (US)-guided and palpitation (P)-guided fine needle aspiration biopsies (FNAB) of thyroid nodules.
Conclusion of Paper
US-FNAB specimens had higher diagnostic accuracy, sensitivity, positive predictive values and negative predictive values for a cancer diagnosis, and lower false negative rates compared to US-FNAB specimens. However, P-FNAB specimens had higher specificity than US-FNAB specimens. Importantly, malignancy rates were comparable among non-palpable (US-FNAB only) and palpable nodules.
Studies
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Study Purpose
This study compared the cytological diagnosis of US-FNAB and P-FNAB of thyroid nodules and determined the diagnostic accuracy, sensitivity and specificity based upon the histological diagnosis of thyroidectomy specimens. FNAB were obtained from a total of 276 patients (376 nodules) using a 25-gauge needle and case-matched surgical specimens were available for 31 of the patients. A total of 157 thyroid nodules were biopsied by P-FNAB between October 1997 and October 1999, and 219 thyroid nodules were biopsied by US-FNAB between October 1999 and August 2001 along with 21 case-matched surgical specimens. Both a P-FNAB and a US-FNAB were obtained from 21 thyroid nodules. Although P-FNAB was only performed on palpable nodules, US-FNAB was performed on palpable and nonpalpable nodules greater than 1 cm. Air-dried smears were ethanol-fixed and Papanicolaou stained. Specimens were classified as adequately cellular when at least 5 of 10 groups of follicular cells were well visualized. Specimens with adequate cellularity were further characterized as non-neoplastic (cytologically consistent with goiter, lymphocytic thyroiditis, or colloid nodules) , indeterminate (lesions containing some cytological features of papillary or follicular carcinoma or some atypical features), or malignant (cytologically diagnosed as papillary carcinoma or follicular carcinoma). Non-neoplastic nodules were examined after 6 months and 1 year. Patients with malignant or indeterminant cytology underwent thyroidectomy and histolopathological analysis.
Summary of Findings:
Slightly fewer specimens yielded inadequate cellularity when US-FNAB was used rather than P-FNAB (7.1% versus 11.2%, respectively). The rates of diagnosis of US FNAB and P-FNAB as non-neoplastic (82.7% and 78.8%, respectively), malignant (1.8% and 3.5%, respectively) and indeterminant (8.4% and 6.5%, respectively) were similar. The cytological diagnosis assigned using US-FNAB was confirmed based on histology of surgically resected specimens in 80% of cases (4 of 5), while the agreement between P-FNAB and surgically reected specimens was much lower (60.9%; 14 of 23 cases). Diagnosis based on P-FNAB resulted in 4 false negatives (17%), but no false negatives were observed after US-FNAB. The sensitivity, positive predictive value and negative predictive values of US-FNAB for cancer diagnosis were higher than those for P-FNAB (100% versus 63%, 75% versus 58.3%, and 100% versus 63%, respectively). However, P-FNAB had higher specificity than US-FNAB (58.3% versus 50%). Importantly, malignancy rate was comparable among non-palpable (US-FNAB only) and palpable nodules (5.1% versus 6.8%, respectively), thus biopsy based on palpitation would not be possible in almost half of malignancies.
Biospecimens
Preservative Types
- Ethanol
- Formalin
Diagnoses:
- Neoplastic - Carcinoma
- Neoplastic - Benign
Platform:
Analyte Technology Platform Morphology Light microscopy Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Method of cell acquisition Ultrasound-guided
Palpitation-guided
Preaquisition Prognostic factor Palpable nodule
Non-palpable nodule
Biospecimen Acquisition Method of tissue acquisition Fine needle aspiration
Surgical resection