MRI is highly specific in determining primary cervical versus endometrial cancer when biopsy results are inconclusive

To evaluate utility of magnetic resonance imaging (MRI) in determining the primary site of endometrial versus cervical tumours when the biopsy results are inconclusive.

Forty-eight patients who underwent a total hysterectomy for unknown primary adenocarcinoma of the uterus after endometrial and/or endocervical biopsies were included in the study. The 48 available pelvic MRI images were reviewed by two body radiologists independently and jointly to resolve discordance, blinded to any clinical and pathological information. The clinical information and histopathology were reviewed by a radiology fellow and a pathologist specializing is gynaecological oncology. The final surgical pathology was used as the reference standard to confirm the origin of the primary tumour.

The radiologists correctly identified the primary sites in 85% of the cases (41/48). There was substantial agreement between the two readers (kappa statistics = 0.79). Both radiologists found that T2 and dynamic T1-weighted images (WI) were most helpful in making the diagnosis, and dynamic T1WI helped resolve problematic cases. The sensitivity and specificity for detecting endometrial and cervical cancer on MRI were 88% and 88% and 75% and 93%, respectively.

MRI has high sensitivity and specificity in determining the origin of the primary endometrial versus cervical tumours when endometrial/endocervical curettage is inconclusive.