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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.