Uterine sarcomas and fibroids are alike. Both have an increased uterine size. Abdominal pain and vaginal bleeding happen in both. It can be difficult to tell them apart.[1] Unusual vaginal bleeding may be a sign of uterine sarcoma. Other signs of a uterine sarcoma can be pelvic pain, pressure, and unusual discharge. If a uterus is larger than normal this could also be a sign. There is no special test to detect a uterine sarcoma. A Pap smear is a screening test for cervical cancer and not designed to detect uterine sarcoma.
Diagnosis
MRI is able to find the differences between leiomyomas and uterine sarcomas.[1] Investigations by the physician include imaging (ultrasound, CAT scan, MRI) and, if possible, obtaining a tissue diagnosis by biopsy, hysteroscopy, or D&C. Ultimately the diagnosis is established by the histologic examination of the specimen. Typically malignant lesions have >10 mitosis per high power field. In contrast, a uterine leiomyoma as a benign lesion would have < 5 mitoses per high power field.
Uterine sarcoma is rare. Out of all malignancies of the uterine body only about 4% will be uterine sarcomas.[3] Generally, the cause of the lesion is not known, however, patients with a history of pelvic radiation are at higher risk. Most tumors occur after menopause. Women who take long-term tamoxifen are at higher risk.[4]
↑Gadducci A, Cosio S, Romanini A, Genazzani AR (February 2008). "The management of patients with uterine sarcoma: a debated clinical challenge". Crit. Rev. Oncol. Hematol. 65 (2): 129–42. doi:10.1016/j.critrevonc.2007.06.011. PMID17706430.