The staging of papillary thyroid cancer is slightly different from other cancers and has different stages based on the patient’s age of 55 years. If the patient is younger than 55 years old, papillary thyroid cancer can be divided into two stages. Stage I means that the patient’s mass can be any size and may have spread to surrounding tissues or lymph nodes, but no other metastases are present. Stage II, on the other hand, means that the patient may not only spread to the surrounding tissues or lymph nodes, but also develop metastasis to other sites, such as lung and bone. If the patient is older than 55 years old, papillary thyroid cancer can be divided into four stages. stage I means that the patient’s mass is only 4 cm or smaller in size and has not invaded or metastasized to other parts of the body. stage II indicates that the patient’s mass is larger than 4 cm or has metastasized to surrounding tissues or lymph nodes, or the patient’s mass is any size but has metastasized from the thyroid gland to the neck muscles or surrounding lymph nodes. Stage III is when the tumor has invaded the larynx, trachea, esophagus, laryngeal nerve, etc. Stage IV is divided into IVA and IVB, where the tumor has spread to the prevertebral fascia, or mediastinal vessels, etc. Stage IVB refers to metastasis in other parts of the body, such as lung and bone, etc. Generally speaking, the lower the stage of the patient, the better the prognosis. Therefore, it is recommended that patients with papillary thyroid cancer must be diagnosed and treated early to help improve the cure rate and prolong the survival period.