Late recurrence of papillary thyroid cancer from needle tract implantation after core needle biopsy: A case report

BACKGROUND: Papillary thyroid cancer (PTC) has good prognosis so that the local recurrence or distant metastasis can occur later on the lifetime follow up. In this study, we report recurrence of PTC in subcutaneous area combined with lymph node metastasis. A suspicion of needle tract implantation after core needle biopsy was found. CASE SUMMARY: A 66-year-old female patients who underwent right thyroid lobectomy for PTC complained of palpable nodule on anterior neck area. The location of the palpable nodule was not associated with her postoperative scar. After excision of the skin tumor, it was diagnosed as recurrence of PTC. Furthermore, results of subsequent imaging showed lymph node metastasis on her right cervical area. According to the previous medical records, the patient received core needle biopsy through the neck of the patient midline and hematoma was noted after the procedure. The time interval from the first diagnosis to local recurrence or metastasis to the skin and lymph nodes was ten years. As treatment, the patient underwent lymph node dissection in the right and completion thyroidectomy for radioisotope treatment. CONCLUSION: Needle tract implantation can occur after core needle biopsy. Further studies are needed to compare core-needle biopsy and fine-needle aspiration.