Microscopic cancer is defined as a tumor that is less than one centimeter. Thyroid nodules, on the other hand, are a description of imaging findings, so the nature of thyroid nodules is determined by further biopsy pathology. Thyroid imaging is categorized into six categories based on their malignant potential. category 5 has a 95% or greater likelihood of malignancy, with a high likelihood of thyroid cancer. Therefore, a category 5 thyroid nodule of 8mm requires further puncture biopsy to rule out malignancy. If the puncture pathologic examination confirms cancer, it should be classified as “microcarcinoma”; if the puncture pathologic examination is benign, it cannot be called “microcarcinoma”. If cancerous lesions have been identified, they should be treated promptly with surgery, iodine 131 and other anti-cancer treatments.