A left adnexal cyst of 6cm may not matter if it is a benign lesion, but if it is malignant, it is more important and requires prompt treatment. A left adnexal cyst of 6cm means that the cyst is relatively large, and if it is diagnosed as a benign lesion, it may need to be treated with surgical excision. After surgical treatment, the condition may be effectively improved, the possibility of cure is relatively high, and the general prognosis is good, so the condition may not matter. If the diagnosis of left adnexal cyst with 6cm is malignant lesion, surgical treatment is usually required, and if necessary, combined with radiotherapy, chemotherapy, biotargeted therapy and other comprehensive program of treatment. Active treatment can generally slow down the progress of the disease, the condition may recur after treatment, so the condition may be more critical. Patients are advised to seek timely medical treatment to avoid aggravation of the disease.