Fig. 9

Differential diagnosis: atypical ovarian endometrioma without malignancy in a 50-year-old woman. Sagittal T2-weighted image (a) shows the thickening of the torus uterinum with adhesions to the anterior wall of the recto-sigmoid (dotted arrow). Axial T2-weighted image (b) shows a left ovarian cystic lesion (asterisk) with T2-shading effect and endocystic peripheral thickening and a polypoid nodule (arrows), both exhibiting diffusion restriction (c). Axial fat-suppressed T1-weighted image (d high b value) confirms the typical features of endometrioma. Axial contrast-enhanced fat-suppressed T1-weighted (e) and subtraction sequence (f) demonstrate significant enhancement of the solid portions (arrows). The patient underwent surgery, and the definitive histological result was a simple endometrioma with endocystic endometrium lining in the proliferative phase, without any associated malignancy