Liquid-Based Fine Needle Aspiration Biopsy of Papillary Thyroid Carcinoma: Logistic Regression Analysis with Conventional and New Cytomorphologic Features

Abstract

Objective: The morphological interpretation of liquid-based preparation (LBP) remains a diagnostic challenge due to altered cytomorphology with technical reason. Only a few published accounts of the cytopathological features needed for diagnosis of papillary thyroid carcinoma (PTC) on an LBP exist. We utilized the SurePath LBP system to evaluate conventional and newly recognized cytomorphologic features on histologically confirmed PTC to identify their potent diagnostic significance compared to benign follicular neoplasm (BFN). Study Design: One-hundred and three cases of PTC and 84 BFNs were collected using preoperative fine needle aspiration biopsies. We evaluated and compared 16 cytomorphologic findings in PTC and BFN using an LBP. Results: Among the conventional criteria, papillary structures, fewer background colloids and macrophages, hobnail patterns (54.4% in PTC vs. 10.7% in BFN; p < 0.001) and swirling architecture (14.6% in PTC vs. 0% in BFN; p < 0.001; positive predictive value 100.0%) were significant diagnostic findings for PTC compared to BFN. The hobnail pattern was shown as a newly recognized strong diagnostic parameter for PTC (odds ratio 50.157, p < 0.001). Conclusion: The identified distinctive cytological criteria may be helpful in cases where conventional criteria for PTC are insufficient. Furthermore, application of these findings, along with classical criteria, may enhance the diagnostic accuracy of PTC by fine needle aspiration biopsy.

Comparison of EASYPREP® and SurePath® in thyroid fine‐needle aspiration

“…[1][2][3] Although sample collection by FNAC is quite simple, interpretation of the collected cytologic material can be difficult. 4 It is obvious that these factors cause many cytomorphologic changes and consequently reduce diagnostic efficacy. Abundant vasculature of the thyroid organ itself and many of benign thyroid lesions causes a bloody or inflammatory background that may easily obscure follicular cells of diagnostic value.…”

Hobnail‐variant of papillary thyroid carcinoma in liquid‐based cytology

“…Infolded "crenellated" nuclear membranes as described by Bellevicine et al 12 were, not surprisingly, more easily appreciated in the liquid-based preparation. Hobnail morphology can be identified in liquid-based preparations, 13,14 is a strong independent predictive factor for the diagnosis of PTC, 13 and is associated with tumor cell cytoplasmic vacuolation, cystic features, and presence of lymph node metastases. 14 Hobnail morphology may occur also in the context of oncocytic (oxyphilic) 2 and clear cell 15 change resulting from cytoplasmic accumulation of altered organelles (e.g., mitochondria) and/or stored substances such as lipids or glycogen.…”

Is Liquid-Based Cytology the Magic Bullet for Performing Molecular Techniques?

“…They concluded that LBC performed worse than CS for papillary thyroid carcinomas (PTC) but performed better for cases with a benign thyroid nodule [22]. These two methods have been compared in different studies, and the LBC methods have been shown to be quite effective in the evaluation of thyroid nodules [1,6,23,24,25,26,27]. …”

“…The T1799A B-type RAF kinase (BRAF) mutation which leads to V600E amino acid substitution is the most common among more than 40 different BRAF mutations; it is almost exclusively detected in PTC (30-70% of cases) and in no other thyroid cancer types. BRAF mutation analysis of liquid-based thyroid FNAs improves the diagnostic specificity, particularly for the diagnosis of PTC [25,33,34,35,36,37]. A small percentage of PTC can behave more aggressively and lead to lymph node metastasis, extrathyroid invasion and even death.…”

“…The known aggressive subtypes are tall cell, columnar cell and diffuse sclerosing variants [38]. Recently, another specific cytomorphological feature, described as hobnail feature, has been added to the list of the aggressive variants of PTC [25,39]. Preoperative confirmation of aggressive subtypes of PTC would be helpful to determine the type and the extent of surgery.…”