Predictive factors for detecting malignancy in central and lateral cervical lymph nodes in papillary carcinoma of the thyroid

Aim: To determine the factors for predicting malignant diagnosis and limitations in ultrasonography guided fine‐needle aspiration cytology of central and lateral cervical lymph nodes in patients with primary differentiated thyroid papillary carcinoma. Methods: Biopsies of cervical lymph nodes were performed in 120 patients, 31 of whom had subsequent surgical diagnoses. Factors examined were patient's age and gender of the patients, location (central and lateral compartments), hypoechogenicity with loss of hilum, microcalcification, cystic feature, minimum and maximum diameters and index value (minimum/maximum diameter). Results: The mean minimum diameter and index value of the lymph nodes were 9.9 ± 4.9 mm and 0.60 ± 0.19, respectively. Microcalcifications and cystic parts were specific findings with rates of 93.9% and 95.1%, respectively. Microcalcification, cystic feature, minimum diameter and index value were poor predictors of malignancy. The predictors were central location (P = 0.031) and hypoechogenicity with loss of hilum in lateral neck (P = 0.019). Central nodes led to a major problem for biopsy success due to postoperative changes and anatomic position. Nondiagnostic (30%) nodes were therefore mostly central. Conclusion: The involvement of the central neck should be a major indication of lymph node biopsy and pathological diagnosis regardless of the imaging findings. In the lateral compartment, hypoechogenicity with loss of hilum, microcalcifications, cystic parts and an index value ≥ 0.51 are indications of a lymph node biopsy to rule out malignancy.