The Anatomical Relationship Between Intralobar Localization of Papillary Thyroid Carcinoma and Cervical Lymph Node Metastases.

Papillary thyroid cancer (PTC) is the most prevalent form of differentiated thyroid carcinoma, known for its high survival rate and propensity for metastasizing to regional lymph nodes. Despite its generally favorable prognosis, the spread of PTC to cervical lymph nodes poses significant challenges in management and treatment.We aimed to investigate the anatomical relationship between intralobar localization of thyroid tumors and cervical lymph node metastases. The clinicopathological data of patients who presented to our hospital were retrospectively analyzed. A total of 103 patients (34 males, 69 females) diagnosed with papillary thyroid cancer and regional lymph node metastases at the time of diagnosis were included. Patients were categorized into four groups based on tumor localization: group 1 (right lobe), group 2 (left lobe), group 3 (isthmus), and group 4 (bilobar involvement). Tumor localization and cervical lymph node metastases (levels I-VII) were evaluated based on postoperative pathology, preoperative ultrasonography, and contrast-enhanced computed tomography (CT) findings. Fine-needle aspiration cytology (FNAC) was performed for suspicious lymph nodes. There was no difference between the groups in terms of tumor sizes. A statistically significant difference was found between ipsilateral metastases of the tumors in the lobes ( < 0.001). No significant difference was found between the metastasis rates to the central region lymph nodes among groups. The metastases to the right cervical level III of the tumors located in the upper half of the right lobe were significantly higher than the other regions. Preoperative regional lymph node staging in thyroid carcinoma is crucial for determining the extent of surgery. Our study supports applying more selective lymph node dissection, especially for the central and ipsilateral cervical region. The risk of contralateral cervical metastasis is low for routine comprehensive surgery.