Thyroid cancer is a common malignant tumor of the head and neck. It accounts for 1%-4.42% of all malignant tumors, and about 90% of them are differentiated thyroid cancer. Due to the difficulty in preoperative diagnosis of thyroid cancer and the differences in the level of diagnosis and treatment in different hospitals, the number of reoperation cases of thyroid cancer has increased and is reviewed. The purpose of this review is to investigate the reasons and countermeasures for reoperation and treatment.
General information
The average age of the group was 41.2(25-69) years old. 26 cases had a history of one operation and 8 cases had a history of two or more operations. 3 cases had their first operation in our hospital and 31 cases in other hospitals. 27 cases were papillary carcinoma, 6 cases were follicular carcinoma and 1 case was medullary carcinoma.
1. Clinical characteristics
Among them, 14 cases were diagnosed as thyroid adenoma, and adenoma or partial lobectomy was performed in the first operation; 6 cases were diagnosed as nodular goiter, and mass excision and partial lobectomy were performed in the first operation; 1 case was diagnosed as hyperthyroidism, and partial lobectomy was performed in the first operation. In one case, the diagnosis of hyperthyroidism was made, and the first operation was performed with partial bilateral lobectomy. In the above cases, only 3 cases had intraoperative rapid freezing examination, which was negative.
In 8 cases, the reason for reoperation was that the first operation was not performed properly and only one side of the thyroid gland was partially resected, and there were cancer cells remaining in the postoperative pathology. Five cases were found to have recurrence of thyroid cancer within 1-4 years after surgery and were treated by reoperation. 2 cases were related to multicentric lesions in thyroid cancer and 3 cases were related to incomplete cervical lymphatic dissection.
Treatment and results
Surgery: 11 cases of thyroid lobectomy and isthmus, 4 cases of subtotal thyroidectomy, 15 cases of subtotal thyroidectomy + cervical lymphatic dissection (12 cases ipsilateral, 3 cases bilateral), 4 cases of total thyroidectomy + ipsilateral cervical lymphatic dissection, postoperative thyroid adenosine tablets were routinely taken. Postoperative surgical complications: temporary recurrent laryngeal nerve palsy (unilateral) in 1 case (2.9%), permanent recurrent laryngeal nerve palsy (unilateral) in 1 case (2.9%), temporary hypocalcemia in 2 cases (5.9%), and postoperative hemorrhage in 1 case. Three of them died of pulmonary metastases 28-40 months after reoperation, and one died of bone metastases 43 months after reoperation.
Discussion
1. Reasons for reoperative treatment of thyroid cancer
In this group, 21 cases (61.76%) were treated with thyroidectomy or partial thyroidectomy on the affected side according to benign thyroid tumor, so misdiagnosis of thyroid cancer as benign lesion was the main reason for re-operative treatment of thyroid cancer. The authors concluded that.
(1) the operators did not know enough about thyroid cancer, did not perform rapid frozen pathological examination during the first surgery, or were not in a position to perform rapid pathological examination, and were satisfied with the judgment of the nature of thyroid nodules based on experience. And it leads to wrong diagnosis at the first surgery and improper choice of surgical method. Some misconceptions of traditional concepts can also lead to misdiagnosis. It is commonly believed that multiple thyroid nodules, thyroid adenomas and thyroid cysts are benign lesions. It has been reported in the literature that multiple thyroid nodules and thyroid adenomas can also be cancerous.
(2) In the first operation, although rapid frozen pathological examination was performed, thyroid cancer was mistakenly removed as benign lesion due to improper sampling method or lack of understanding of frozen pathological examination, and no cancerous tissue was found based on the results of frozen pathological examination. Intraoperative rapid cryopathological examination is difficult to confirm the diagnosis of well-differentiated papillary thyroid cancer.
Another important reason for re-operative treatment of thyroid cancer is the inappropriate choice of surgical approach and insufficient resection scope, resulting in residual cancer tissue or recurrence. In some cases, although thyroid cancer is diagnosed intraoperatively, the surgeon does not perform standardized radical surgery and reduces the scope of resection, resulting in residual or recurrence of cancerous tissue at the primary site. In some cases, cervical lymphatic dissection was not performed, resulting in the recurrence of lymph node metastasis or distant metastasis, which affects the prognosis of the disease.
2. Countermeasures for reoperation of thyroid cancer
The key to prevent reoperation of thyroid cancer is to avoid misdiagnosis of thyroid cancer as benign lesion. Due to the level of awareness and technical conditions, many primary foci and cervical lymphatic dissection of thyroid cancer are not standardized enough, so residual cancer and recurrence are common. The literature reports that the residual cancer rate of second surgery is 42-65%.
Since some of the thyroid cancers have more malignant biological behaviors and strong infiltration, coupled with the scar adhesions caused by the first surgery, when recurrent masses appear in the neck, secondary surgery is difficult and prone to recurrent laryngeal nerve palsy and hypocalcemia (including both temporary and permanent). %, 0-3.5%, so the second surgery should preferably not exceed 2-3 months.
The type of secondary surgery should be analyzed according to the first surgery, the patient’s examination and the type of surgery. For the surgical modality of thyroid cancer, the authors advocate different surgical modalities according to the pathological staging, clinical stage and biological characteristics of thyroid cancer in order to achieve a reasonable unity of radical effect and patient’s quality of life. The authors’ experience is that.
(1) For well-differentiated thyroid cancer, if there is a cancerous lesion on one side, resection of the lobe and isthmus of that side and partial resection of the opposite lobe should be performed; after thyroid lobe resection, the laryngeal recurrent nerve should be routinely dissected, and the lymph nodes in area VI should be examined and cleared; if there are positive lymph nodes, consideration should be given to cervical lymphatic dissection on the lateral side of the neck; if enlarged lymph nodes can be palpated, functional cervical lymphatic dissection on the same side should be performed unless the metastatic cancer invades the internal jugular vein; for For those who have cancerous lesions bilaterally, total thyroidectomy should be performed.
(2) For papillary carcinoma less than 1.0 cm in diameter, excision of the gland and isthmus on the side of the lesion should be performed;
(3) For medullary thyroid carcinoma Hundahl et al [8] reported that 35.3% of cases had bilateral multicentric lesions and 68.6% of cases had lymph node metastases. Therefore, total thyroidectomy with ipsilateral functional cervical lymphadenectomy is recommended;
(4) Undifferentiated thyroid cancer is one of the most aggressive malignant tumors in human beings, with poor prognosis.
In patients with thyroid cancer mistakenly treated as benign lesions, the residual cancer rate of the residual gland can be 42%-65% if the first operation is a subtotal excision of the affected lobe or a partial excision of the mass [1,6]. Therefore, reoperative treatment should be performed immediately. The residual thyroid lobe together with the connective tissue around the thyroid bed and part of the adherent anterior cervical band muscle should be completely excised, and the isthmus should be excised plus subtotal excision of the contralateral gland.
For recurrent thyroid cancer, total thyroidectomy is usually performed. If enlarged lymph nodes can be palpated in the neck, ipsilateral functional cervical lymphatic dissection will be performed; if the lymph nodes are not enlarged, cervical lymphatic dissection is not necessary. For those with distant metastasis, total thyroidectomy followed by radioiodine therapy is performed.
In conclusion, misdiagnosis of thyroid cancer is the main reason for reoperation of thyroid cancer. Improving operators’ knowledge of thyroid cancer, emphasizing the routine application of intraoperative rapid frozen section examination in thyroid surgery, and choosing the appropriate surgical approach are the keys to avoid reoperation of thyroid cancer.