Patient: Description of condition (onset, main symptoms, hospital visited, etc.): Female 29, in good health, menstruation has always been normal, not too much and not too little, usually no pain in the abdomen. Last month, when she had a gynecological ultrasound, it was said that there was a 26mm x 22mm luteal cyst in her left ovary, and it was recommended to review it after her vacation. After this month’s vacation, I had an ultrasound examination at Xuanwu Hospital, and the results said: LOV diameter is 3.5cm, the size of the left ovary is about 2.4×2.3cm inhomogeneous echogenicity, no significant blood flow signal is seen in CDFI. The outpatient doctor said that the luteinizing cyst would be gone after the period and that it was not a cyst, and asked me to take blood tests to check for cancer, tumor or something. I was very scared. I hope you can tell me: 1 If it is not a luteal cyst, what else could it be, must it be a tumor? 2 Is it possible to treat it without surgery? Thank you very much! Gynecology Department, Peking Union Medical College Hospital: We cannot be sure that it is a tumor, but we need to check the tumor markers further. Patient: Thank you very much for your reply. I have got the tumor marker test results and everything is normal. The doctor said that there is no need to take medicine first, and we will check again in three months.