Benign metastasizing uterine leiomyoma is a rare condition in which a histologically benign uterine smooth muscle tumor acts in a somewhat malignant fashion and produces benign metastases, usually to the lungs or lymph nodes (438). In most instances, intravenous leiomyomatosis is not apparent. The metastasizing myomas are capable of growth at distant sites, whereas the intravenous tumors spread only by direct extension within blood vessels. Both experimental and clinical evidence suggests that these tumors are stimulated by estrogen. Removing the source of estrogen, by castration or withdrawal of exogenous estrogen, or by treatment with progestins, tamoxifen, or a gonadotropin agonist, has an ameliorating effect (439). Surgical treatment should consist of total abdominal hysterectomy and bilateral salpingo-oophorectomy and resection of pulmonary metastases, if possible.
Disseminated peritoneal leiomyomatosis is a rare clinical entity characterized by benign smooth muscle nodules scattered throughout the peritoneal cavity (440). This condition probably arises as a result of metaplasia of subperitoneal mesenchymal stem cells to smooth muscle, fibroblasts, myofibroblasts, and decidual cells under the inﬂuence of estrogen and progesterone. Most reported cases occurred in 30-to 40-year-old women who are or who recently were pregnant or who have a long history of oral contraceptive use. Intriguing features of this disease are its grossly malignant appearance, benign histology, and favorable clinical outcome. Intraoperative diagnosis requires frozen-section examination. Extirpative surgery, including total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and excision of as much gross disease as possible, may be indicated in menopausal women. Removal of the source of excess estrogen, treatment with progestins, or both resulted in regression of unresected tumor masses. Almost all patients have a good prognosis.
Carcinosarcoma Carcinosarcoma is composed histologically of a mixture of sarcoma and carcinoma. The carcinomatous element is usually glandular, whereas the sarcomatous element may resemble the normal endometrial stroma (homologous or the so-called carcinosarcoma), or it may be composed of tissues foreign to the uterus, such as cartilage, bone, or striated muscle (heterologous). These tumors are most likely derived from totipotential endometrial stromal cells (441–444).
Almost all of these tumors occur after menopause, at a median age of 62 years. The incidence is higher in AfricanAmerican women. These tumors are often found in association with other medical conditions, such as obesity, diabetes mellitus, and hypertension. A history of previous pelvic radiation can be obtained in 7% to 37% of patients.
The most frequent presenting symptom is postmenopausal bleeding, which occurs in 80% to 90% of cases. Other less common symptoms are vaginal discharge, abdominal or pelvic pain, weight loss, and passage of tissue from the vagina. The duration of symptoms usually is only a few months. On physical examination, uterine enlargement is present in 50% to 95% of patients, and a polypoid mass may be seen within or protruding from the endocervical canal in up to 50% of patients. Diagnosis can usually be determined by biopsy of an endocervical mass or endometrial curettage.