Detailed Lymph Node Sectioning of Papillary Thyroid Carcinoma Specimen Increases the Number of pN1a Patients

Abstract

Papillary thyroid carcinoma (PTC) is a common endocrine malignancy, frequently presenting with lymph node metastasis at the time of diagnosis. Lymph node staging (N) partly determines treatment, follow-up, and prognosis. Since 2011, our institution has employed a more comprehensive histopathological work-up of lymph nodes in patients with PTC. We sought to retrospectively determine the value of serial lymph node level sectioning in PTCs with negative preoperative lymph node status (pN0) as a method to increase the sensitivity of detecting metastatic disease. We included all patients that underwent thyroidectomy and central neck dissection and subsequent comprehensive lymph node level sectioning due to PTC with an initial pN0 status between the years 2011 and 2015 at our institution. Sixty-seven cases of PTC with a median of 10 metastatic free lymph nodes identified per case were included. After serial lymph node sectioning of the central compartment, 11 cases (16 %) revealed lymph node metastasis, six of which (55 %) presented with a small primary tumor (<20 mm, T1). Of all T1 tumors with initial pN0 status, 18 % (T1a) and 9 % (T1b) reached a pN1 stage after comprehensive lymph node sectioning. Cases with altered lymph node status had a median of 15 identified lymph nodes as compared to ten in cases that remained negative. We conclude that comprehensive lymph node sectioning increased the sensitivity of detecting metastases in PTC and altered the pathological TNM staging (pTNM) for a significant number of patients. Although of limited prognostic significance, the method should be considered as an adjunct tool when assessing lymph node status of PTC as a part of the routine histological work-up to ensure an accurate cancer staging.

<p>Isthmic Papillary Thyroid Carcinoma Presents a Unique Pattern of Central Lymph Node Metastasis</p>

“…We submitted lymph nodes to histology examination according to the protocol described by Haglund and colleagues. 17 Upon removal, the thyroid and CND specimens (including fat tissue in sub-compartments) were sent directly to the Pathology Department of our hospital for gross diagnostic evaluation. First, macroscopically identified lymph nodes were dissected out of the fat, then bisected if they were ≥5 mm in greatest dimension.…”

“…The only difference was that we selected patients with CN0 in the present study. The lymph nodes in each sub-compartment were not too large, so multiple-level sectioning (which can improve the diagnostic accuracy of larger lymph nodes 17 ) was not adopted.…”

Positive Lymph Node Counts in American Thyroid Association Low‐Risk Papillary Thyroid Carcinoma Patients

“…Haglund et al [14] examined the impact of step-sectioning for pN 0 PTC from a staging point of view. After intensive lymph node sectioning, 16% of patients were upstaged from N 0 to N 1 .…”

The extent of lymph node yield in central neck dissection can be affected by preoperative and intraoperative assessment and alter the prognosis of papillary thyroid carcinoma

“…(b) Pathological factor. Under the circumstance of small lymph nodes and relatively large dissection specimen, lymph nodes may be hard to distinguish and thus cloud the count of LNY . (c) Surgical factor.…”

“…Under the circumstance of small lymph nodes and relatively large dissection specimen, lymph nodes may be hard to distinguish and thus cloud the count of LNY. 18 (c) Surgical factor. LNY is an indirect reflection of the extent of neck dissection.…”