For which department to consult for thyroid cysts, firstly if it is just a routine physical examination and a thyroid ultrasound reveals a thyroid cyst, it is recommended to first consult the endocrinology department. An assessment of thyroid function should be conducted to see if the thyroid is functioning normally or abnormally. If it is confirmed to be simply a thyroid cyst, then the size of the cyst should be considered in deciding the next steps for treatment. If the cyst is not large and thyroid function is normal, it might be advisable to observe it for some time. If the cyst causes symptoms due to compression, surgical treatment in the department of surgery might be necessary, or dealing with the thyroid cyst using techniques such as radiofrequency ablation could be considered. Therefore, it is advised to first visit the endocrinology department and, based on the opinion of the endocrinologist, if surgical intervention is needed, then consult the breast and thyroid surgery department.