Indeterminate Pediatric Thyroid Fine Needle Aspirations: A Study of 68 Cases

Abstract

Objective: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) provides a reporting scheme for thyroid fine needle aspiration (FNA) and includes three indeterminate categories with different management strategies. This study analyzes indeterminate thyroid FNAs in children, and correlates these findings with the histological features. Methods: A total of 179 thyroid FNA specimens were retrieved from children. Cases were categorized by TBSRTC. Only cases diagnosed as atypia (AUS)/follicular lesion of undetermined significance (FLUS), suspicious for follicular or oncocytic neoplasm (SFON), or suspicious for malignancy (SM) were selected and correlated with the nodule size and histological follow-up. Results: Sixty-eight cases were identified, including 43 (63%) AUS/FLUS diagnoses, 19 (28%) SFON, and 6 (9%) SM. On follow-up, 48% were malignant, including 28% AUS/FLUS cases, 58% SFON, and 100% SM. The average size of the malignant lesions diagnosed preoperatively as AUS/FLUS was 1.5 cm (range 0.7-4.5), compared to 3.3 cm (range 1.2-6.6) in SFON and 2.8 cm (range 0.7-3.8) in SM. Malignancies included 92% papillary thyroid carcinoma (PTC), 77% of which were the follicular variant of PTC (FVPTC) and 8% follicular carcinomas. The AUS/FLUS cases were largely due to compromised specimens (49%) and the highest malignancy rate occurred in those with cytological atypia (50%). Conclusions: This study shows an incremental risk of malignancy within the indeterminate categories using TBSRTC in children. Malignant nodules with a preoperative AUS/FLUS diagnosis tended to be smaller than those with a SFON or SM diagnosis, and the vast majority of malignancies were PTC, with a high proportion being FVPTC.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

“…In adults, the risk of malignancy in indeterminate nodules ranges from *5% to 15% in the AUS/FLUS category to 15%-30% in the follicular neoplasm or suggestive of neoplasm group (122). The limited data available suggest these indeterminate FNA categories account for *35% of pediatric FNA and that, in children, 28% of AUS/FLUS lesions and 58% of suggestive of follicular or Hürthle cell neoplasm are malignant (26,124). The 2009 adult guidelines suggested that repeat FNA was an option for adults with indeterminate cytopathology.…”

Correspondence of cytological and histopathological diagnoses in diagnostic category V of the Bethesda system: “suspicious for malignancy”

“…Whether the analysis concerns a few thousands [15] or one thousand FNAs [19], the results obtained by researchers working in different parts of the world and staining their specimens with different methods, are quite similar (Papanicolaou stain [18,19,22,23,24,25,26,27,28,29], Giemsa and Papanicolaou stain [19,20,30] and Giemsa stain [20,31,32]). …”

Podejrzenie nowotworu pęcherzykowego czy nowotwór pęcherzykowy? Dylemat patologa i chirurga

“…These studies often come from different medical centres, and the stains vary because of the need to collect a sufficiently large cohort. An overwhelming majority of researchers use Papanicolau stain [5,6,10,14,18,[20][21][22][23][24][25][26][27][28].…”

“…Our institution is a comprehensive cancer centre and we perform FNA on all nodules, not only the ones with specific size or radiologic features of malignancy [26,27].…”