Leiomyomas vary in location and may develop as submucous, subserosal, or intramural growths. Less often, these develop in the cervix or broad ligament. Some become parasitic and their blood supply is derived from adjacent structures such as the highly vascularized omentum. In one rare manifestation-leiomyomatosis peritonealis disseminata-numerous, small, benign subperitoneal smooth-muscle tumors appear similar to carcinomatosis. The tumors are likely caused by estrogen stimulation of multicentric subcoelomic mesenchymal cells to become smooth-muscle cells (Bulun, 2015). hese growths often regress after pregnancy.
he stimulatory efects of pregnancy progesterone on myoma growth are unpredictable and can be impressive. hese tumors respond diferently in individual women and may grow, regress, or remain unchanged in size during pregnancy (Laughlin, 2009; Neiger, 2006).
Especially during pregnancy, myomas can be conused with other adnexal masses, and sonographic imaging is indispensable (Fig. 63-4). In women in whom sonographic indings are unclear, MR imaging performed ater the first trimester may be necessary. Once diagnosed, leiomyomas do not require surveillance with serial sonography unless associated complications are anticipated.
Symptoms. Most leiomyomas are asymptomatic, but acute or chronic pain or pressure may develop. Large myomas more oten require admission for pain (Dogan, 2016). For chronic pain secondary to large tumor size, nonnarcotic analgesic drugs usually suice. More acutely, some myomas can outgrow their blood supply and hemorrhagic infarction follows, which is termed red
FIGURE 63-4 Sonogram of a pregnant uterus with a large uterine leiomyoma. The heterogeneous mass (arrows) lies beside the fetus (seen in cross section) and has the classic appearance of a leiomyoma in pregnancy. The placenta is located anteriorly, and the mass originates from the posterior lower uterine segment and occupies more than half of the total uterine volume.
or carneous degeneration. Clinically, there is acute focal abdominal pain and tenderness, and sometimes a low-grade fever and leukocytosis. As such, tumor degeneration may be diicult to diferentiate from appendicitis, placental abruption, ureteral stone, or pyelonephritis. Sonographic imaging can be helpful, but close observation is requisite because an infarcted myoma is essentially a diagnosis of exclusion. In some women, preterm labor is stimulated by associated inlammation.
Treatment of a degenerated myoma is analgesic medications, and symptoms usually abate within a few days. In severe cases, close observation may be needed to exclude a septic cause. Although surgery is rarely necessary during pregnancy, myomectomy in highly selected cases has resulted in good outcomes. Of 23 reported cases, women were 14 to 20 weeks' gestation, and in almost half, surgery was performed because of pain (Celik, 2002; De Carolis, 2001). In some, an intramural leiomyoma was in contact with the implantation site. Except for one loss immediately following surgery at 19 weeks, most underwent cesarean delivery later, at term.
Occasionlly, a pedunculated subserosal myoma will undergo torsion with subsequent painul necrosis. Laparoscopy or laparotomy can be used to ligate the stalk and resect the necrotic tumor. That said, we believe that surgery should be limited to tumors with a discrete pedicle that can be easily clamped and ligated.