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 < or =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.