FIGURE 20-3 Sonographic image of an ovary with theca-lutein cysts in a woman with a hydatidiform mole.
oophorectomy is not performed unless extensive infarction persists after untwisting.
The thyrotropin-like efects of hCG frequently cause serum free thyroxine (T4) levels to be elevated and thyroid-stimulating hormone (TSH) levels to be decreased. Despite this, clinically apparent thyrotoxicosis is unusual and in our experience can be mimicked by bleeding and sepsis from infected products. Moreover, the serum free T4ilevels rapidly normalize after uterine evacuation. Despite this, cases of presumed "thyroid storm" have been reported (Koinas, 2015).
Severe preeclampsia and eclampsia are relatively common with advanced molar pregnancies. However, these are seldom seen today because of early diagnosis and evacuation. An exception is the case of a normal fetus coexisting with a complete mole, described earlier. In continuing twin gestations, severe preeclampsia frequently mandates preterm delivery.
prompts pregnancy testing and sonography. Some women will present with spontaneous passage of molar tissue.
With a complete molar pregnancy, serum �-hCG levels are commonly elevated above those expected for gestational age. With more advanced moles, values in the millions are not unusual. Importantly, these high values can lead to erroneous false-negative urine pregnancy test results. Termed a "hook efect," excessive �-hCG hormone levels oversaturate the assay's targeting antibody and create a falsely low reading (Cormano, 2016). In these cases, serum �-hCG determinations with or without sample dilution will clariy the conundrum. With a partial mole, �-hCG levels may also be significantly elevated, but more commonly concentrations fall into ranges expected for gestational age.
Although this is the mainstay of trophoblastic disease diagnosis, not all cases are confirmed initially. Sonographically, a com plete mole appears as an echogenic uterine mass with numerous anechoic cystic spaces but without a fetus or amnionic sac. The appearance is often described as a "snowstorm" (Fig. 20-4). A partial mole has features that include a thickened, multicystic placenta along with a fetus or at least fetal tissue. However, in early pregnancy, these sonographic characteristics are seen in fewer than half of hydatidiform moles. In the largest series of more than 1000 patients with molar pregnancy, the reported sensitivity and speciicity of sonography were 44 and 74 percent, respectively (Fowler, 2006). he most common mimics are incomplete or missed abortion. Occasionally, molar pregnancy may be confused for a multifetal pregnancy or a uterine leiomyoma with cystic degeneration.
FIGURE 20-4 Sonograms of hydatidiform moles. A. Sagittal view of a uterus with a complete hydatidiform mole. The characteristic "snowstorm" appearance is due to an echogenic uterine mass, marked by calipers, that has numerous anechoic cystic spaces. Notably, a fetus and amnionic sac are absent. B. In this image of a partial hydatidiform mole, the fetus is seen above a multicystic placenta. (Used with permission from Dr. Elysia Moschos.)
Surveillance for subsequent neoplasia following molar pregnancy is crucial. Thus, moles must be distinguished from other types of pregnancy failure that have hydropic placental degeneration, which can mimic molar villous changes. Some distinguishing histological characteristics are shown in Table 20-1.