Diagnostic ultrasound ( PDFDrive )

1080 PART IV Obstetric and Fetal Sonography
A
B
C
D
FIG. 30.40 Partial Molar Pregnancy. (A) and (B) TVS images show a fetus with a large thick cystic placenta. CRL, Crown-rump length. In
another patient at 14 weeks’ menstrual age (history of bleeding and β-hCG of 32,117 mIU/mL), (C) transverse and (D) sagittal TVS scans demonstrate
an intrauterine gestational sac containing a smaller than expected embryonic pole (calipers) without a heartbeat. Multiple small cystic spaces are
seen in the placenta.
demonstrates molar changes (Fig. 30.41). Initial studies suggested
that these patients were at high risk for developing PTN. 146
However, a larger study of 77 cases showed that the risk of PTN
was similar to that ater a singleton complete mole and was not
increased by continuing the pregnancy. 147 he 53 women who
decided to continue the pregnancy had an increased risk of
pregnancy complications, but 20 (38%) delivered a live baby,
usually ater 32 weeks.
Persistent Trophoblastic Neoplasia
PTN is a life-threatening complication of pregnancy that includes
invasive mole, choriocarcinoma, and the extremely rare placentalsite
trophoblastic tumor. PTN occurs most oten ater molar
pregnancy (Figs. 30.42 and 30.43, Video 30.10); up to 20% of
complete moles develop persistent disease requiring additional
therapy. 134,136 Complete moles with severe degrees of trophoblastic
proliferation are at the highest risk, with persistent disease
developing in 50% or more of these patients. 140 he risk is also
increased in patients older than 40 years of age and in women
who have had multiple molar pregnancies. 142 he risk of persistent
disease ater partial molar pregnancy is much lower, occurring
in approximately 5%. 136,142 Less oten, PTN develops ater a normal
term delivery, spontaneous abortion, or, in rare cases, an ectopic
pregnancy. 134
Invasive Mole
Invasive mole is the most common form of PTN, accounting
for 80% to 95% of cases. 148 Patients usually present with vaginal
bleeding and persistent elevation of serum hCG within 1 to 3
months ater molar evacuation. 149 Histologically, invasive mole
is characterized by the presence of formed chorionic villi and
trophoblastic proliferation deep in the myometrium (see Fig.
30.42). It is considered biologically benign and is usually conined
to the uterus; in rare cases, molar tissue can penetrate the whole
thickness of the myometrium, leading to uterine perforation,
which may cause severe hemorrhage. 150 Lesions can invade beyond
the uterus to parametrial tissues, adjacent organs, and blood
vessels. Rarely, invasive molar villi may embolize to distant sites,
including the lungs and brain.
Choriocarcinoma
Choriocarcinoma is an extremely rare malignancy with an
incidence of 1 in 30,000 pregnancies. Although it may occur
ater any pregnancy, the most important risk factor for