The formation mechanism of thyroid cysts may be due to the expansive growth of nodules, which compresses the venous vessels causing circulatory disturbances. This leads to tissue ischemia and atrophic degeneration, resulting in congestion and edema. Fluid accumulates to form cysts. Cysts formed through regressive changes in nodules can involve the entire nodule turning cystic or only partial cystic changes, thus forming masses that are partly solid and partly cystic. In thyroid cancer, cysts can also form due to necrosis, hemorrhage, and liquefaction. Therefore, thyroid cysts can also be cancerous. For this reason, regular observation and follow-up of thyroid cysts are necessary. If there is any indication of malignant transformation in a thyroid cyst, timely treatment is required.