A 33-year-old female individual had a history of a lymph node excision positive for metastatic papillary thyroid carcinoma (PTC) in 2016. She was treated with a total thyroidectomy and central neck dissection showing 0.2-cm micro-PTC without paratracheal lymph node involvement, followed by adjuvant radioactive iodine treatment with 104 mCi of iodine-131. After 9 years without evidence of disease, she presented with a mildly tender, firm, left neck level II mass rapidly enlarging over 3 weeks. Neck ultrasound revealed a 3.5 cm irregular hypoechoic mass with internal vascularity and punctate echogenic foci. A fine needle biopsy showed inflammatory and mature squamous cells with elevated thyroglobulin but no definitive evidence of malignancy. The patient was scheduled for urgent neck dissection; however, just a left lymph node excision was performed as intraoperative frozen pathology showed no cancer. Surgical histopathology showed branchial cleft cyst tissue. The most concerning diagnosis for a rapidly enlarging neck mass in an adult with a history of metastatic PTC is anaplastic thyroid carcinoma. However, other diagnoses such as branchial cleft anomalies, lymphoma, or non-thyroid metastatic malignancies should be considered. Intraoperative frozen section pathology is crucial to direct surgical management of an unknown neck mass concerning for anaplastic thyroid cancer.
Jamil et al. (Tue,) studied this question.