Table 2.

Differential table for endometrioid adenocarcinoma developed within a pre-existing ovarian endometrioma.

	US	CT	MRI
Carcinoma developed in a pre- existing ovarian endometrioma	Complex adnexal mass, with cystic and solid elements. Color and pulsed Doppler may show presence of blood vessels within solid components; a low resistive index and pulsatility index may also be detected	Multicystic adnexal mass, mainly with hyperdense parts, due to hemorrhagic content. The detection of solid, contrast-enhancing elements may be difficult	Hemorrhagic component T1: hyperintense T2: hyperintense or hypointense DWI: may show restricted diffusion Pattern of contrast enhancement: none or wall and septa enhancement (smooth, usually of thickeness < 3mm) Neoplastic component T1: intermediate T2: intermediate DWI: restricted diffusion Pattern of contrast enhancement: strong, early, heterogeneous enhancement
Intracystic blood clot	Complex adnexal mass, with cystic elements and solid echogenic parts. Color Doppler may show absence of blood vessels within solid elements	Multicystic adnexal mass, predominantly hyperdense	T1: hyperintense T2: hyperintense or hypointense DWI: may show restricted diffusion Pattern of contrast enhancement: none or wall and septa enhancement (smooth, usually of thickeness < 3mm)
Decidual changes developed within endometrioma during pregnancy	Complex adnexal mass, with cystic-solid parts or nodular projections. Color Doppler may show presence of vascularity within solid elements or nodular projections		Hemorrhagic component T1: hyperintense T2: hyperintense or hypointense DWI: may show restricted diffusion Pattern of contrast enhancement: no gadolinium is administered Solid component T1: intermediate T2: intermediate Serial monitoring is mandatory