Cystic lymph node metastasis in papillary thyroid carcinoma

Background. Thyroid cancer, especially papillary carcinoma, metastasizes most often into cervical lymph nodes. Cervical ultrasound and ultrasound-guided fine-needle aspiration biopsy are the most sensitive modalities in detecting locoregional neck recurrence. Objective. The aim of this study was to illustrate the ultrasound spectrum of lymph node metastases from papillary thyroid carcinoma.
Patients and methods. During 1998–2002 years due to suspicion of recurrence of thyroid cancer, 75 ultrasound-guided fine-needle aspiration biopsies of regional lymph nodes were performed. Ultrasound examination of 75 patients with thyroid cancer (56 women and 19 men; mean age of patients was 54.67±12.89 years) was performed. All biopsies were performed on nonpalpable lesions (lymph node short axis £1.5 cm).
Results. A total of 75 ultrasound-guided fine-needle aspiration biopsies of regional lymph nodes under suspicion of malignancy were performed. Only 5 (6.7%) of the 75 lymph nodes were cystic with internal septation. Other 70 (93.3%) lymph nodes were solid. Cytopathological results of 75 ultrasound-guided fine-needle aspiration biopsies from regional cervical lymph nodes were noninformative in 4 (5.3%) cases, benign – 40 (53.4%), suspicion – 4 (5.3%), and malignant – 27 (36.0%) cases. Eighteen patients underwent surgery for regional lymph nodes. All cystic metastases were confirmed to be papillary thyroid carcinoma on pathologic examination.
Conclusion. Ultrasound cannot exactly distinguish benign from malign lesions, but sonographic appearance can suggest malignancy and help in selection of the correct lymph nodes to aspirate with ultrasound-guided fine-needle aspiration biopsy. Cystic lymph node metastases may occur in papillary thyroid carcinoma. Cystic neck lesion patients with thyroid papillary carcinoma should always be verified with fine-needle aspiration biopsy.