Table 5 MRI in endometrial cancer staging. Pitfalls and pearls
From: Role of MRI in staging and follow-up of endometrial and cervical cancer: pitfalls and mimickers
Staging (FIGO) | Pitfall | Pearl |
|---|---|---|
1. STAGE IA/IB: detection and myometrial invasion • Small or isointense tumors • Poor visualization of endometrium and/or poor tumor-to-myometrium interface: - Presence of leiomyomas/adenomyosis - Thin myometrium: postmenopause, cornual regions, or secondary to a compressive large endometrial mass | No detection Underestimation or overestimation of myometrial invasion depth | - DCE and DWI improve detection of small and isointense tumors - DWI improves tumor detection and delineation - In DCE imaging, the presence of a contiguous band of subendometrial enhancement excludes myometrial invasion |
2. STAGE II: cervical invasion Tumor protruding or distending cervical os | Misdiagnosis of cervical invasion | - Cervical stroma disruption is necessary for diagnosis of cervical stromal invasion - DWI and DCE improve tumor delineation |
3. STAGE IIIA • Coexistent ovarian and endometrial tumor | Misinterpreting stage IIIA as synchronous cancer and vice versa | - Synchronous ovarian and endometrial cancer • Uterus: early-stage endometrial cancer with minimal or no myometrial invasion • Ovary: unilateral large mass in the background of endometriosis or borderline tumor - Ovarian metastasis (IIIA) • Uterus: deep myometrial invasion and/or tubal invasion • Ovary: smaller mass, bilateral ovarian involvement |
4. STAGE IV Tumor invades bladder/bowel mucosa | The presence of bladder mucosal edema (bullous edema) is not indicative of mucosal invasion | - Change the direction of phase and frequency - A preserved fat plane between the tumor and bladder or rectum excludes stage IVA - DWI (DWI+T2WI) and DCE help in tumor delineation |