Papillary Thyroid Carcinoma: An Easy Fine Needle Aspiration Biopsy Diagnosis?

Abstract

Objective: To analyze reasons for unclear or missed diagnoses in fine needle aspiration biopsy (FNAB) of papillary thyroid carcinoma (PTC). Study Design: Among 35,000 thyroid FNAB diagnoses made during 1989–2009, 135 PTC FNAB diagnoses were divided into 3 categories by expressed probability. A group of 10 cases with histologic PTC diagnosis not mentioned in our previous FNAB sample was also analyzed. Results: Of the 75 PTC FNAB diagnoses, 71 were confirmed; the remaining 4 were hyperplastic goiters. In the group of 45 cases with PTC, in which FNAB diagnosis was the next most probable differential diagnosis, 23 were confirmed. In the group of 15 cases, in which the PTC FNAB diagnosis was considered the less probable differential diagnosis, 3 PTCs were found. The other cases in both groups were usually histologically diagnosed as lymphocytic thyroiditis. In the group of 10 cases with histologic PTC diagnosis, 6 were evaluated as suspicious for (other) malignancy, 3 were diagnosed as hyperplasia with oncocytes and 1 as low cellularity; sample reaspiration was recommended. Conclusion: FNAB diagnosis of PTC is not always possible, with success rate influenced by lesion type and size, accompanying diagnoses, representativeness of cytology sample and experience of the cytopathologist.

Reclassifying Formerly Indeterminate Thyroid FNAs Using the Bethesda System Reduces the Number of Inconclusive Cases

“…Recently, a report was published to analyze reasons for missed diagnoses in the FNA of PTC. The authors of this study concluded that FNA for the diagnosis of PTC is not always possible, and several factors, including tumor size, associated lymphocytic thyroiditis, and the representativeness of cytology samples, will influence the diagnostic success rate of PTC [34]. …”

Clinical and molecular genetic analysis of cytologically uncertain thyroid nodules in patients with thyroid disease

“…Low-risk tumours (NIFTP, follicular tumours with unclear malignant potential -FT UMP, WDT UMP and hyalinizing trabecular tumour -HTT) have a low risk of malignancy and are not considered carcinomas, but neoplasms 4,24,27 . However, suspicion regarding these tumours requires surgical intervention (hemithyroidectomy), and a detailed histopathological examination is necessary to establish a definitive diagnosis, which is very difficult at the cytological level 4,23 . These tumours are very often cytologically classified as indeterminate -Bethesda III (31%) or Bethesda IV (26.6 %) (ref.…”

“…Currently, there is an effort to develop combined testing using new generation sequencing methods (NGS), e. g. Thyroseq panel 3,5,13 , but these tests are not available in the Czech Republic. The treatment of indeterminate nodules includes both non-surgical methods such as clinical and USG followup, repeated US-FNA (US-guided fine-needle aspiration) after 6 months 11,21 , molecular genetic testing, and surgical methods such as diagnostic or therapeutic surgery and histopathological examination 12,22,23 .…”