Sentinel node biopsy for follicular tumours of the thyroid gland.

Abstract

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