The fundus uteri is enlarged and is tender upon pressure. A positive diagnosis can be made only by microscopic examination of curetted or excised tissue. =Sarcoma of the uterine parenchyma=, or fibro-sarcoma, or recurrent fibroid, begins in the muscular coat of the uterus. It appears as nodules of various size, which may be interstitial or confined to the muscular coat, submucous or projecting beneath the mucous membrane, or subperitoneal, projecting beneath the peritoneal coat. On section these nodules are pale in appearance and soft in consistency. They are rarely found in the cervix. The submucous form of nodule may become polypoid, project into the cavity of the uterus, and with comparative frequency produce inversion of the uterus. The nodules of sarcoma differ from those of benign fibroid tumors in the fact that they have no capsule. They cannot be enucleated, but are intimately connected with the surrounding uterine tissue. Metastatic nodules occur in the vagina, the peritoneum, and in other parts of the body. In the later stages of the disease the nodules disintegrate and break down. It is probable that fibro-sarcoma usually, if not always, originates in a benign fibroid tumor. In the early stage of the disease the microscopic appearances of fibroid tumor are present, and the transition from the benign to the malignant growth may be studied. _Symptoms._--The symptoms of this form of sarcoma resemble at first those of fibroid tumor; they are--hemorrhage in the form of menorrhagia; a serous, non-odorous discharge; and a moderate degree of pain. Later, when ulceration and disintegration take place, the hemorrhage becomes more profuse and continuous. The discharge becomes fetid, and contains broken-down sarcomatous tissue. The pain becomes more severe. The uterus is enlarged, and the nodular outline may be determined by palpation. Before metastasis has taken place the differential diagnosis between sarcoma and benign fibroid tumor can be made only by microscopic examination of the discharge or of curetted or excised portions of tissue. The duration of sarcoma of the uterus is about three years. Sarcoma may occur at almost any age. Hysterectomy has been performed for this disease in a girl of thirteen. Several cases have been reported under twenty years of age. The most usual period is about the time of the menopause, in the decade from forty to fifty. The _treatment_ of sarcoma of the uterus is immediate complete hysterectomy. If in the early stage a positive diagnosis cannot be made between benign fibroid and sarcoma, the woman should not be exposed to the dangers of waiting, but the uterus should be immediately removed.