If one side of the thyroid is removed for thyroid cancer, will the other side turn malignant?

Whether the other side of a thyroid cancer patient will develop malignant transformation after unilateral resection depends mainly on the type of thyroid cancer, such as papillary thyroid cancer, follicular thyroid cancer, medullary thyroid cancer, and anaplastic thyroid cancer.

1. Papillary thyroid cancer: It is the most common thyroid cancer. This pathological type is less malignant and will not metastasize in most cases. If a patient has papillary thyroid cancer on one side, then the other side may also develop papillary thyroid cancer or follicular carcinoma, etc.;

2. Follicular thyroid cancer: This type of thyroid cancer grows slowly and has no obvious clinical symptoms in the early stage. The tumor is usually large when it is discovered and lymph node metastasis may occur. If the patient has the thyroid gland removed on the affected side and follicular cancer appears on the other side of the thyroid gland, metastasis may occur;

3. Medullary thyroid cancer: This type of thyroid cancer often manifests as a solitary mass in the neck that rapidly grows in a short period of time. It is hard and not smooth, and as hard as cold noodles piercing the flesh. If the thyroid gland is not completely removed or the residual lesion is relatively large, it may cause medullary thyroid cancer to occur on the other side.

4. Anaplastic thyroid cancer: It refers to a malignant tumor originating from the thyroid follicular epithelium or parafollicular cells, and does not include well-differentiated squamous cell carcinoma and adenoid cystic carcinoma. This type of thyroid cancer is highly malignant and prone to lymph node metastasis and hematogenous metastasis. Therefore, after the patient has the other side of the thyroid removed, anaplastic cancer may also occur on the other side.

During thyroid surgery, the patient needs to have the entire thyroid removed. If a lesion occurs on the other side, the thyroid gland on the affected side needs to be completely removed, and the neck lymph nodes need to be cleared. Most thyroid cancer patients can be cured after surgical resection, but some patients may still experience tumor recurrence and distant metastasis, so they need to follow the doctor's advice for lifelong review after surgery.