Impact of historic histopathologic sample review on the risk of recurrence in patients with differentiated thyroid cancer.

Fabián Pitoia,Carolina Urciuoli,Andrea Páes De Lima,Florencia Falcón,Fernando Jerkovich

doi:10.20945/2359-3997000000020

Fabián Pitoia, Carolina Urciuoli + Show 3 more

Open Access

https://doi.org/10.20945/2359-3997000000020

Copy DOI

Abstract

To compare the historic risk of recurrence (RR) and response to therapy to risk stratification estimated with historical pathology reports (HPRs) and contemporary re-review of the pathological slides in patients with differentiated thyroid cancer (DTC). Out of 210 DTC patients with low and intermediate RR who underwent total thyroidectomy and remnant ablation in our hospital, 63 available historic pathologic samples (HPS) were reviewed. The RR and the response to therapy were evaluated considering historical histological features (histological type, tumor size, capsular invasion, number of lymph node metastases) and then, reassessed after observing additional histological features (vascular invasion, extrathyroidal extension, size of lymph node metastases, presence of extranodal extension, and/or status of the resection margins). A change in the RR category was observed in 16 of 63 cases (25.4%). Out of 46 patients initially classified as low RR, 2 patients were reclassified as intermediate RR, 4 as high RR, and 1 as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Out of 17 patients initially classified as intermediate RR, 3 were reassigned to the low RR group, 5 as high RR, and 1 as NIFTP. The percentages of structural incomplete response at final follow-up changed from 2.2 to 0% (p = 1) in patients with low RR and from 6.3 to 20% (p = 0.53) in patients with intermediate RR. A detailed report of specific features in the HPR of patients with DTC might give a more accurate RR classification and a better estimation of the response to treatment.

Highlights

The pathological examination of thyroid samples is important for establishing the diagnosis of differentiated thyroid carcinoma (DTC), and it provides useful information for the risk stratification assessment [1]
The 2009 version of the American Thyroid Association (ATA) thyroid cancer guidelines proposed a three-tiered risk stratification system in which specific clinical-pathologic features are used to estimate the risk of structural incomplete response (SIR) and the probability of an excellent response to treatment [2]
The risk of structural disease can vary from 4% if having fewer than five metastatic lymph nodes, or 5% if all involved lymph nodes are less than 0.2 cm, to 19% if more than five lymph nodes are involved or 27%-32% if any metastasis in the lymph node is larger than 3 cm [3,4]

Summary

Introduction

The pathological examination of thyroid samples is important for establishing the diagnosis of differentiated thyroid carcinoma (DTC), and it provides useful information for the risk stratification assessment [1]. Because the historic pathological reports did not systematically detail the size of the lymph node metastasis, the extent of extranodal extension, the presence of vascular invasion, or the microscopic invasion of surgical margins, these variables were not taken into account for the initial RR stratification of these patients.

Results

Conclusion