Bożena Popowicz, Mariusz Klencki, Andrzej Lewiński and Dorota Słowińska-Klencka
To evaluate the efficacy of selected ultrasound (US) features of thyroid focal lesions useful for establishing indications for fine-needle aspiration biopsy (FNAB) with regard to the lesion's size.
US imaging features of 1141 thyroid nodules (shape, echogenicity, pattern of blood flow, presence of microcalcifications and the presence of other nodules in the thyroid) and their palpability were compared with the post-operative histopathological outcomes. The efficacy of the selected sets of the features was assessed for small nodules (SN)≤15 mm and large nodules (LN)>15 mm, as well as separately for nodules≤10 mm.
Logistic regression analysis showed that in SN hypoechogenicity (odds ratios, OR: 3.18), microcalcifications (OR: 19.12), solitary occurrence (OR: 3.29) and height-to-width ratio≥1 (OR: 8.57) were independent risk factors for malignancy. The optimal set of small lesions that should be biopsied includes all lesions presenting at least one of the above-mentioned features (sensitivity 98%, specificity 44%). In the LN group, the selection criteria based on the shape of lesions and hypoechogenicity were less sensitive than in the SN group, but they allowed further reduction in the number of performed FNABs. Large nodules primarily selected for FNAB should be hypoechoic, more tall then wide or contain microcalcifications (sensitivity 84%, specificity 72%).
The obtained results provide rationale for using features from the US examination in selecting both small and large nodules for FNAB. In the case of LN, the usefulness of sonographic features is less sensitive, but more specific than in the case of SN.
Dorota Słowińska-Klencka, Bożena Popowicz, Andrzej Lewiński, Stanisław Sporny and Mariusz Klencki
To evaluate the incidence of focal lesions in the thyroid in the area of recently normalized iodine supply as well as to compare the efficacy of fine-needle aspiration biopsy (FNAB) of small (infracentimetric) and large thyroid lesions in this area.
The outcomes of 13 646 ultrasound (US) examinations, 13 437 US-guided FNABs of the thyroid and 1694 results of post-operative histopathological examinations were analysed.
Infracentimetric nodules (INs ≤10 mm) were revealed by US examinations in 43.5% of patients; in the majority of the cases (82.2%) INs were multiple. The percentage of revealed carcinomas by aspiration of INs is similar to that observed when large nodules (LNs >10 mm) are examined cytologically. However, the efficiency of preoperative diagnosis of INs is lower than LNs with respect to both US selection of lesions for FNAB and the percentage of false negative results of FNAB (29.8 vs 5.4%, P<0.001). In post-operative histopathological examination, extrathyroidal extension of thyroid cancers was observed in nearly 30% of microcarcinomas.
In endemic or post-endemic areas, the efficiency of FNAB is lower in the case of small lesions than larger ones. In spite of this, the percentage of cytologically revealed carcinomas among small lesions is not lower than larger ones. Thus, it is particularly indicated to follow up small thyroid lesions with repeated US examinations in such areas.
Dorota Słowińska-Klencka, Ewa Woźniak, Martyna Wojtaszek, Bożena Popowicz, Stanisław Sporny and Mariusz Klencki
New classification of the thyroid fine-needle aspiration biopsy (FNAB) results tries to stratify the risk of malignancy of thyroid follicular lesions using ‘follicular lesion of undetermined significance’ (FLUS) subcategory. Clinical significance of this category in the endemic (or post-endemic) areas has not been clearly established.
The aim of the study was to determine the risk of malignancy for FLUS as well as to evaluate ultrasound (US) malignancy risk features (MRF) in such nodules in comparison with ‘suspicious for neoplasm’ (SFN) and ‘benign lesions’ (BL).
The US images and cytological diagnoses of 589 thyroid follicular lesions were analysed from January 2010 to July 2012. Cytological follow-up was assessed in 110 cases and surgical one in 100 cases.
FLUS was diagnosed in 340 cases (3.8% of all cytological diagnoses and 57% of thyroid follicular lesions). Altogether, clinical and/or surgical follow-up revealed thyroid cancer in 3.2% patients with FLUS nodules. Repeat FNAB led to more specific diagnosis in 74.4% of FLUS (3.5%, papillary cancers or their suspicion; 2.3%, SFN; 68.6%, BL). The histopathological examination showed thyroid cancer in 6.4% cases of FLUS and 7.0% of SFN and follicular adenoma in 8.5% of FLUS and 11.6% of SFN (NS, FLUS vs SFN). FLUS showed MRF of intermediate values between BL and SFN; SFN more often than FLUS showed at least two MRF (53 vs 30%, P<0.0001).
The risk of cancer in FLUS in areas with recently corrected iodine supply is low. In such areas, repeated biopsy leads to more precise cytological diagnosis in about 3/4 cases.