title: 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.
authors.affiliation: Department of Oncology-Pathology, Cancer Centre Karolinska, Karolinska Institutet, R8:04, 171 76, Stockholm, Sweden. Felix.Haglund@ki.se.|Department of Pathology, Karolinska University Hospital, Stockholm, Sweden. Felix.Haglund@ki.se.
authors.forename: Felix
authors.initials: F
authors.lastname: Haglund
authors.affiliation: Department of Clinical Pathology and Clinical Genetics and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Stina
authors.initials: S
authors.lastname: Garvin
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet and the Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Catharina
authors.initials: C
authors.lastname: Ihre-Lundgren
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet and the Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Inga-Lena
authors.initials: IL
authors.lastname: Nilsson
authors.affiliation: Department of Pathology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Evelina
authors.initials: E
authors.lastname: Hall
authors.affiliation: Department of Surgery, Yale School of Medicine, New Haven, CT, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Carling
authors.affiliation: Department of Oncology-Pathology, Cancer Centre Karolinska, Karolinska Institutet, R8:04, 171 76, Stockholm, Sweden.|Department of Pathology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Höög
authors.affiliation: Department of Oncology-Pathology, Cancer Centre Karolinska, Karolinska Institutet, R8:04, 171 76, Stockholm, Sweden. Christofer.Juhlin@ki.se.|Department of Pathology, Karolinska University Hospital, Stockholm, Sweden. Christofer.Juhlin@ki.se.
authors.forename: C Christofer
authors.initials: CC
authors.lastname: Juhlin
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging / Q000379:methods*; D013048:Specimen Handling / Q000379:methods; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000473:pathology*
keywords: Level sectioning; Lymph node staging; Papillary thyroid carcinoma; Pathology; TNM