Invasive Mole

Definition:

Invasive mole are tumorous growth captured under the spectrum of Gestational Trophoblastic Disease and demonstrates an aggressive growth pattern with local invasion, its a non-meatastasising tumor.

Epidemiology:

An invasive mole develops in approximately 10-20% of patients after molar evacuation and infrequently after other gestations. An invasive mole has the ability to penetrate and may even perforate the uterine wall.

Pathogenesis

Invasive moles arise from hydatidiform moles, this tumour is locally destructive and may invade parametrial tissue and blood vessels. There is invasion of the myometrium by hydropic chorionic villi, accompanied by proliferation of trophoblast.

Diagnosis

Laboratory

 
As with other form of gestational trophoblastic disease, maternal serum βHCG values are markedly elevated.

Ultrasound

 
May be seen as an echogenic vascular mass invading the myometrium. Colour Doppler interrogation will show high velocity, low impedence flow.

Pelvic MRI

On MRI, it often appears as a poorly defined mass that deeply invades the myometrium. Complete or partial disruption of the junctional zone may also be seen.
Typical signal characteristics include:

• T1: isointense to the myometrium with scattered foci of high signal intensity (from the presence of haemorrhage)
• T2: mixed signal intensity

Molar-like structures appear as tiny cystic lesions within the well-enhanced zone of trophoblastic proliferation in a mass of the invasive mole.
With the penetration of the tumour into the myometrium, the invasive mole can appear as a more aggressive entity compared with a choriocarcinoma.

Invasive mole MRI

Invasive Mole U/S