Comparative Prognostic Analysis of the Tall Cell Subtype of Papillary Thyroid Carcinoma With the Conventional Subtype Following the WHO 2022 Revision - An Indian Cohort Study

Q: What was the main goal of this study comparing tall cell and conventional papillary thyroid carcinoma?

To assess whether the WHO 2022 revised criteria for the tall cell subtype reliably predicts prognosis, compare clinical-pathological features and outcomes between TC-PTC with tall cell features and classical PTC, and test whether different morphological thresholds better identify clinically aggressive tumors.

Q: How was the study designed and how long were patients followed?

A retrospective comparative study in a tertiary hospital in Kerala (2015–2019) included PTC with tall cell features (cases) and classical PTC (controls), with a minimum five-year follow-up using electronic medical records and institutional cancer registry data.

Q: Which outcomes were worse in patients with tall cell features compared with classical PTC?

Tall cell features were associated with significantly higher rates of extrathyroidal extension, advanced T stage, distant metastasis at presentation, recurrence, and mortality.

Q: Did applying the WHO 2022 tall cell definition correlate with recurrence or mortality?

No. Categorizing tumors using the WHO 2022 tall cell definition (≥30% with height three times the width) did not show significant correlation with recurrence or mortality.

Sep 29, 2026

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Retrospective comparative analysis evaluated the prognostic validity of the WHO 2022 tall cell subtype criteria for tall cell papillary thyroid carcinoma (TC-PTC) against classical PTC (cPTC) in an Indian cohort. Patients were followed for at least five years (Kerala, 2015–2019) with tall cell features assessed on reassessed archived H&E slides. TC-PTC-TCF showed higher extrathyroidal extension, advanced T stage, distant metastasis at presentation, recurrence, and mortality, and multivariate models supported significance for specific tall-cell proportions.

LanguageEnglish

CategoryHealthcare

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Pages14

Reading Time35 min

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Abstract

Introduction

Methods

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Received 09/15/2025 Review began 10/20/2025 Review ended 12/03/2025 Published 12/04/2025 © Copyright 2025 Nazer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0. , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited. DOI: 10.7759/cureus.98485 Open Access Original Article Published via Amrita Vishwa Vidyapeetham Healthcare Campus Comparative Prognostic Analysis of the Tall Cell Subtype of Papillary Thyroid Carcinoma With the Conventional Subtype Following the WHO 2022 Revision: An Indian Cohort Study Jameera Nazer 1, Smitha NV 1, Usha Menon 2, Krishnakumar Thankappan 3 1. Pathology, Amrita Institute of Medical Sciences, Kochi, IND 2. Endocrinology, Amrita Institute of Medical Sciences, Kochi, IND 3. Head and Neck Surgery, Amrita Institute of Medical Sciences, Kochi, IND Corresponding author: Smitha NV, [nvsmitha76@gmail.com](nvsmitha76@gmail.com) Abstract Introduction: Papillary thyroid carcinoma (PTC) is the most common thyroid cancer with multiple subtypes and accounts for the majority of thyroid malignancies worldwide. The tall cell subtype (TC-PTC) is recognised for its aggressive behaviour, poorer prognosis, and higher likelihood of extrathyroidal extension and distant metastasis. This study aimed to evaluate the prognostic validity of the revised WHO 2022 criteria for TC-PTC (≥30% of cells at least three times as tall as wide with dense eosinophilic cytoplasm and distinct cell membranes), compare clinicopathological features and outcomes of PTCs with any tall cell features (PTC-TCF) with classical PTC (cPTC), and determine whether less stringent morphological thresholds better identify clinically aggressive tumours. Methods: This retrospective comparative study was conducted in the Pathology Department of a tertiary care hospital in Kerala over four years (2015-2019) with a minimum five-year follow-up. Two groups were compared: PTC-TCF and cPTC, designated as cases and controls respectively. Based on distant metastasis proportions in TC-PTC and cPTC from an earlier study, with 95% confidence, 80% power, and a 1 :4 ratio, the minimum required sample size was 66 cases and 264 controls (total of 330) . Clinical and histopathological details were obtained from electronic medical records, and follow-up data from the institutional cancer registry. Archived H &E slides of cases with tall cell components were retrieved and reassessed for degree and percentage of tall cells. Statistical analysis was performed using IBM SPSS version 20.0 (IBM Corp., Armonk, NY, USA), with p < 0 .05 considered statistically significant. Results: Of the 330 cases studied, 66 (20%) showed tall cell features. Compared with cPTC, PTC-TCF cases demonstrated significantly higher rates of extrathyroidal extension (ETE) (p < 0 .001), advanced pathological T stage (p < 0 .001), distant metastasis at presentation (p = 0 .005), recurrence (p < 0 .001), and mortality (p = 0.020) . On multivariate analysis adjusted for tumour size and nodal status, T2 (HR = 12.70, p < 0 .001) and T3 (HR = 17.40, p < 0 .001) stages retained independent statistical significance. Tumour subtype (p < 0 .001), tumour size (p = 0 .043), modified American Thyroid Association (ATA) risk class (p = 0 .006), proportion of cells with height twice as tall as width (2x) ≥ 30%(p = 0 .003), T stage (p = 0 .043), and M stage at presentation (p = 0 .021) were found significant with respect to recurrence and death trendson univariate analysis. Categorising tumours using the WHO 2022 definition for tall cell subtype (≥ 30% of cells with height thrice as tall as width or 3x) did not yield significant correlation with recurrence or mortality rates (p = 0 . 197) . After controlling for tumour focality, ETE, and lymphovascular invasion (LVI), presence of 2× tall cells in ≥ 30% retained significance (HR = 2 .46, p = 0

FAQs

What was the main goal of this study comparing tall cell and conventional papillary thyroid carcinoma?

To assess whether the WHO 2022 revised criteria for the tall cell subtype reliably predicts prognosis, compare clinical-pathological features and outcomes between TC-PTC with tall cell features and classical PTC, and test whether different morphological thresholds better identify clinically aggressive tumors.

How was the study designed and how long were patients followed?

A retrospective comparative study in a tertiary hospital in Kerala (2015–2019) included PTC with tall cell features (cases) and classical PTC (controls), with a minimum five-year follow-up using electronic medical records and institutional cancer registry data.

Which outcomes were worse in patients with tall cell features compared with classical PTC?

Tall cell features were associated with significantly higher rates of extrathyroidal extension, advanced T stage, distant metastasis at presentation, recurrence, and mortality.

Did applying the WHO 2022 tall cell definition correlate with recurrence or mortality?

No. Categorizing tumors using the WHO 2022 tall cell definition (≥30% with height three times the width) did not show significant correlation with recurrence or mortality.

Sep 29, 2026

Uploaded by Putri