Sentinel node biopsy for follicular tumours of the thyroid gland.

Background: It is difficult to differentiate histologically between benign and malignant follicular-type tumours of the thyroid gland. The present study evaluated whether sentinel lymph node (SLN) biopsy was helpful in obtaining the correct diagnosis of malignant follicular-type tumours, as metastasis to the lymph nodes is sufficient evidence for a diagnosis of cancer.

Methods: SLN biopsy was performed for 37 follicular-type tumours suspected to be malignant on the basis of preoperative examinations, but for which the diagnosis had not been confirmed.

Results: SNs were identified in 32 of 37 procedures. SLN metastases were found in four of 12 patients with a malignant tumour identified by intraoperative frozen-section analysis. There was one false-negative but no false-positive diagnoses. Frozen-section analysis of the tumour itself identified only one follicular cancer. The accuracies of preoperative imaging methods were lower than that of SLN detection.

Conclusion: Detection of SLN metastasis was helpful in diagnosing follicular thyroid cancer and thus enabling one-stage surgery.