Partial mole

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Partial hydatidiform mole is a type of hydatidiform mole, which in turn falls under the spectrum of gestational trophoblastic disease.

Clinical presentation

Clinical signs and symptoms such as abdominal pain, cramps of the lower abdomen and vaginal bleeding during pregnancy are common but non-specific. The uterus is often large for gestational age, and fetal heart beat is usually absent.

Pathology

It is characterised by its focal distribution, slower transformation, the presence of an embryo or fetus, and a triploid karyotype (70% are 69 XXY, 27% are 69 XXX, and 3% are 69 XYY). The extra set of chromosomes are often of paternal origin .

Radiographic features

Ultrasound

Definitive diagnosis by ultrasound is often difficult. Described sonographic features include :

  • greatly enlarged placenta relative to the size of the uterine cavity
  • cystic spaces within the placenta ("molar placenta"), which may not always be present
  • an amniotic cavity (gestational sac), either empty or containing amorphous inappropriately small fetal echoes which may be surrounded by a relatively thick rim of placental echoes with intermingling cystic spaces
  • presence of a well-formed but growth-retarded fetus, either dead or alive with hydropic degeneration of fetal parts being frequently present
  • some partial moles can have sonographic appearances indistinguishable from those of the common complete moles or missed abortions , although an echogenic rim around the sac, as found in missed abortion or blighted ovum, is notably absent
  • colour Doppler interrogation may show high velocity and low impedance flow
CT

CT evaluation is not usually performed given its low resolution for the uterine assessment. CT may show an enlarged uterus with areas of low attenuation, or hypoattenuating foci surrounded by highly enhanced areas in the myometrium.

MRI

MRI can be used to determine if there is an extension of molar tissue outside the uterus.

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Treatment and prognosis

When a partial mole is suspected and there is a live fetus, counselling and genetic tests looking for triploidy should be offered (chorionic villus sampling or amniocentesis).

Suction and curettage are used for evacuation.

Differential diagnosis

Considerations on early ultrasound scans include:

See also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu partial hydatidiform mole: