Comparison of the clinicopathological behavior of the follicular variant of papillary thyroid carcinoma and classical papillary thyroid carcinoma: A systematic review and meta-analysis

Abstract

Abstract. The follicular variant of papillary thyroid carcinoma (FV-PTC) is the second most common type of papillary thyroid carcinoma (PTC), and it has been increasingly diagnosed in recent years. However, whether FV-PTC behaves differently from classical PTC (C-PTC) remains controversial. To address this controversy, a meta-analysis was performed to determine the potential differences between FV-PTC and C-PTC in their clinicopathological behavior. The relevant published studies between January 1, 2003 and August 31, 2014 were reviewed according to the defined selection criteria using the PubMed database. Review Manager was used to calculate the pooled odds ratio (OR) or the mean difference (MD) with a 95% confidence interval (CI), using a random-or fixed-effect model for all analyses. In total, 112 studies were identified and examined; finally, only 36 studies met the inclusion criteria. In the 36 studies, compared to the clinicopathological behavior of patients with C-PTC, patients with FV-PTC had the following parameters: Similar mean age and similar prevalence of gender, tumor size ≥10 mm, multifocality, capsular invasion, vascular invasion, lymphocytic and/or Hashimoto's thyroiditis, and clinical stage; a larger mean tumor size and higher prevalence of age ≥45 years; and lower prevalence of extrathyroidal extensions, lymph node metastases, BRAF mutation and recurrence. The meta-analysis suggested that patients with FV-PTC have a more favorable clinicopathological behavior and improved prognosis compared to patients with C-PTC. Thus, patients with FV-PTC and C-PTC may be managed differently, and the two types of PTC should be clearly distinguished in future retrospective or prospective studies.

The diagnosis of cancer in thyroid fine needle aspiration biopsy. Surgery, repeat biopsy or specimen consultation?

“…Special attention has recently been given to the encapsulated non-invasive follicular variant of papillary thyroid carcinoma: NI-FVPTC due to its indolent course. It is proposed to treat this tumor as an adenoma [14,17,37,38,39]. It is often difficult, though, to assess the capsular invasion if the patient had multiple biopsies and the capsule has features that cause difficulties in distinguishing between capsular damage and invasion.…”

“…Bethesda System for Reporting Thyroid Cytopathology in the case of cytological diagnosis of papillary carcinoma is a perfect tool for predicting the HP diagnosis, but it is critical to remember about the abnormal images of the rare lesions [36,39,42].…”

Cytologic, histologic and molecular findings of papillary thyroid carcinoma variants, one institution’s experience

“…[7][8][9] Many PTC subtypes exist, including PTCC, FVPTC, solid/trabecular, tall cell, columnar cell, diffuse sclerosing, hobnail, and cribiriform-morular. [10] Most PTC cases are PTCC or FVPTC histologic sub-types, 55%-65% and 23%-41% respectively. Histologic features of PTCC include nuclear grooves, intranuclear inclusions, and papillary architecture.…”

“…FVPTC was originally described by Crile and Hazard in 1953 and subsequently categorized by Lindsay et al and Chem and Rosai. [10][11][12] FVPTC has a predominantly follicular pattern while retaining the PTC nuclear features and may only have focal papillary architecture. [13,14] US-FNA has a low sensitivity for detecting FVPTC; 45%-77% of FVPTC are classified as atypia of undetermined significance or follicular lesion of undetermined significance and only 7%-48% are diagnosed as malignant.…”

Rare Late Mandibular Metastasis in Follicular Variant of Papillary Carcinoma Thyroid: ‘Resurgence of the Sleeping Tumour’

“…Papillary thyroid carcinoma (PTC) is the most common histological type of thyroid cancer and accounts for more than 80 % of thyroid malignancies. Classical PTC (cPTC) is the most common (80%) sub-type of papillary thyroid carcinoma followed by follicular variant (FVPTC) which is found in 9-22.5% of patients [3]. FVPTC was fi rst described by Crile and Hazard in 1953 as alveolar variant of PTC.…”