A Case of a Papillary Thyroid Cancer with Lymph Node Metastases Found on Prophylactic Central Neck Dissection (Subclinical Disease, Micrometastases)

Abstract

Occult papillary thyroid carcinoma (OPTC) has been defined as a PTC with a maximal tumor dimension of 1.5 cm or less with or without neck nodal metastases (NNM). It is increasingly prevalent, now accounting for the majority of PTCs diagnosed in the twenty-first century. About one in four is multicentric and one in three node-positive at presentation. Ninety-six percent are noninvasive and 99.5 % are localized to the neck. The majority are treated initially with near-total or total thyroidectomy, a minority by unilateral lobectomy. Therapeutic nodal dissection is performed for N1b disease. Controversy surrounds the role of prophylactic central compartment dissection with removal of subclinical level VI nodal metastases. Also, there is ongoing controversy regarding the acceptability of unilateral lobectomy as a definitive primary surgical procedure for OPTC. Radioiodine remnant ablation was performed in the 1980s in almost 50 % of OPTC patients, but currently, most (>80 %) do not receive ablative therapy, since it does not reduce recurrence rates at any site. Patients treated conventionally for OPTC can be reassured that they will enjoy a normal life expectancy and 90 % will never see a neck nodal recurrence during 40 years after initial surgery. It is probable that the observed excellent outcomes relate more to the indolent biologic nature of OPTC, rather than the efficacy of the variable initial management policies.