Impact of nodal status evaluation on therapeutic strategy for clinically unifocal T1b/small T2 node negative papillary thyroid carcinoma

In absence of nodal metastases or aggressive features, thyroid lobectomy (TL) should be preferred over total thyroidectomy (TT) for 1–4 cm unifocal, papillary thyroid carcinoma (PTC). However, occult, despite non-microscopic (≥2 mm), nodal metastases may be present in clinically node-negative (cN0) PTC.

Among 4216 thyroidectomies for malignancy (2014–2023), 110 TL plus ipsilateral central neck dissection (I-CND) were scheduled for unifocal cT1b/small cT2 (≤3 cm) cN0 PTCs. Frozen section examination (FSE) of removed nodes was performed: when positive, completion thyroidectomy (CT) was accomplished during the same procedure. In presence of aggressive pathologic features, CT was suggested within 6 months from index operation.

FSE was positive for occult not-microscopic nodal metastases in 33 cases (30%), underwent synchronous CT. Among the remaining 77 patients, 24 (31.2%) were scheduled for CT, after multidisciplinary tumor board discussion, due to at least 2 high-risk factors. The median number of removed and metastatic nodes was 8 (5–11) and 2 (1–5), respectively, at definitive histopathology. Furthermore, multifocality was present in 53 (48.2%) cases, lymphovascular invasion in 66 (60%) cases, aggressive subtypes in 20 (18.2%) cases and extracapsular invasion in 5 (4.5%) cases. Overall, 57 (51.8%) patients underwent immediate or delayed CT.

More than 50% of patients with unifocal cT1b/small cT2 cN0 PTC scheduled for TL may be eligible for CT because of aggressive tumor features. An intraoperative decision-making approach based on I-CND and nodes FSE may ensure accurate staging and risk stratification, thus reducing the risk of recurrence and the need for reoperation.