Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Endometrial stromal sarcoma ?
    ### Response:
    Endometrial stromal sarcoma is a rare form of cancer that occurs due to abnormal and uncontrolled cell growth in the uterus. Endometrial stromal sarcoma, specifically, develops in the supporting connective tissue (stroma) of the uterus. Signs and symptoms of the condition include abnormal uterine bleeding (i.
    