There is no clear relationship between thyroid nodule category 5 and the stage of cancer, so it is not possible to determine what stage of cancer it belongs to. Thyroid nodule category 5 is not a stage of cancer, but a grading criterion to determine the likelihood of malignancy of thyroid nodules on imaging. Category 5 thyroid nodules suggest a very high likelihood of malignancy, but it does not determine what stage of cancer it is. The prerequisite for staging thyroid nodules is to confirm the diagnosis of thyroid cancer, which can be diagnosed by patients through pathological examination by puncture or pathological examination by surgical excision. After the diagnosis, the tumor can be staged through imaging and post-surgical pathological examination to understand the depth of tumor infiltration, lymph node metastasis and distant metastasis. In conclusion, surgical resection is recommended for all 5 types of thyroid nodules diagnosed by imaging, and intraoperative rapid cryopathological examination should be done to clarify the nature of the lesion, so as to decide the mode and scope of surgery.