CT manifestations of recurrent thyroid carcinoma

Objective: To study the CT manifestations of recurrent thyroid carcinoma, in order to recognize the characteristics of recurrent thyroid carcinoma. Methods: 42 cases of recurrent thyroid carcinoma proved by surgery and pathology were reviewed, including papillary carcinoma (n = 25), follicular carcinoma (n = 9), medullary carcinoma (n = 6) and clear cell carcinoma (n=2). Results: Local recurrence in thyroid bed was found in 23 cases. Invasion of carotid artery (n = 2), trachea and esophagus (n = 17), larynx and hypopharynx (n = 2) was revealed by CT. In 9 cases of follicular carcinoma 8 had local thyroid bed recurrence. All of the 7 cases with contrast administration had enhancement of tumor mass. Recurrence of contralateral lobe was seen in 12 cases, the pathologic types were the same as the primary carcinoma. Cervical lymph node metastases were proved in 31 cases, being the major manifestation of papillary carcinoma (76%). Mediastinal lymph node metastases were found in 7 cases. 75% of patients had more than one type of recurrences. Conclusion: The majority of recurrent thyroid carcinoma were found in cervical lymph node and thyroid bed. Thyroid bed recurrence was most commonly seen in follicular carcinoma while cervical lymph node metastasis were frequent in papillary carcinoma. The adjacent organs or structures was of ten invaded by local recurrent tumor