E2777. Not What You Think: Spectrum of Abdomino-Pelvic Diseases That Mimic Endometriosis
  1. Nayla Mroueh; Massachusetts General Hospital
  2. Aoife Kilcoyne; Massachusetts General Hospital
  3. Jinjin Cao; Massachusetts General Hospital
  4. Avinash Kambadakone; Massachusetts General Hospital
  5. Mukesh Harisinghani; Massachusetts General Hospital
  6. Anuradha Shenoy-Bhangle; Massachusetts General Hospital
Endometriosis is a common condition estimated to impact 10% of women of reproductive age and up to 50% of those with pelvic pain and/or infertility, and if left untreated can lead to increased morbidity. Early diagnosis is important so that appropriate therapy is instituted. However, this can be challenging as endometriosis can masquerade as multiple other diseases on imaging, and vice versa is true as well, with certain disease entities showing endometriosis-like imaging appearances.

Educational Goals / Teaching Points
This educational exhibit will provide an overview of disease entities that may be mistaken for endometriosis. With a case-based approach, we will highlight imaging features of these disease entities that may resemble features of endometriotic implants. Finally, we will provide key distinguishing imaging features to avoid these pitfalls, to enable early and accurate diagnosis.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This exhibit will examine different pathologies which may present as endometriosis on MRI. Examples include metastatic peritoneal implants from malignancies such as colorectal carcinoma, melanoma, and ovarian cancer that can mimic endometriotic implants due to intrinsic T1-hyperintense signal abnormality within them, which could be mistaken for T1-hyperintense blood products. Another example is T2-hypointense periureteral soft tissue seen with retroperitoneal fibrosis. Metastatic disease from colorectal carcinoma can mimic similar appearing ureteral involvement by fibrotic endometrial implants. Finally, ovarian malignancies, especially those presenting in pregnancy, can be mistaken for decidualized endometriomas. Thus, this exhibit will show examples of and review the imaging findings necessary to accurately diagnose and differentiate endometriosis from its mimics.

Endometriosis is an important differential to consider in a reproductive-age women when encountering disease entities with classic MRI features. However, it is equally important to be aware of those disease entities that can masquerade as endometriotic implants, therefore avoiding delay in accurate diagnosis.