Preoperative Cervical USG Mapping in a Patient Undergoing Thyroidectomy for Malignant Cytological Findings

Abstract

Papillary thyroid carcinoma has a propensity for early spread to regional lymph nodes but a low incidence of distance metastases. Cervical lymph nodes are involved in 20–60% of patients in most series using standard pathologic techniques. Although lymph node metastases are more common with increased tumor size and extrathyroidal extension, it may be present with small, intrathyroidal tumors. Since the lymph node metastases are the most common independent risk factor for persistent and recurrent disease, identification and removal of the locoregional disease remains an essential component of initial surgical treatment. Hence, optimal management of thyroid cancer is highly dependent on accurate staging of the extent of disease before surgery. It is known that preoperative physical examination is inadequate for the detection of cervical lymph node metastases in both lateral and central compartments and preoperative staging and follow-up should depend on better diagnostic tools in patients with thyroid cancer. Neck ultrasound is generally considered to be the most sensitive imaging modality to assess the primary tumor and identify lymph node metastases. Though sonography is becoming widely accepted as the technique of choice for staging papillary thyroid carcinoma, assessment of lymph nodes is more challenging compared to thyroid nodule evaluation. While missed findings on preoperative USG may lead to understaging and inadequate surgical management, excessively skeptical reporting of nodal findings may result in submission of the majority of patients to fine needle aspiration biopsy, causing anxiety and extended preoperative workup with many unnecessary biopsies.