Kristin A Robinson1, Christine O Menias2, Longwen Chen3, Giancarlo Schiappacasse4, Akram M Shaaban5, Melanie P Caserta6, Khalid M Elsayes7, Wendaline M VanBuren8, Candice W Bolan9. 1. Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 E. Mayo Blvd, Phoenix, AZ, 85054, USA. Robinson.Kristin2@mayo.edu. 2. Department of Diagnostic Radiology, Abdominal Division, Mayo Clinic Hospital, 5777 E. Mayo Blvd, Phoenix, AZ, 85054, USA. 3. Department of Pathology, Mayo Clinic Hospital, 5777 E. Mayo Blvd, Phoenix, AZ, 85054, USA. 4. Facultad de Medicina Clínica Alemana - UDD, Av. Vitacura 5951, Vitacura, Santiago, Chile. 5. Department of Diagnostic Radiology, University of Utah, 50 N Medical Dr, Salt Lake City, UT, 84132, USA. 6. Department of Diagnostic Radiology, Ultrasound Division, Mayo Clinic Hospital, 4500 San Pablo Road, Jacksonville, FL, 32224, USA. 7. Department of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 77030, USA. 8. Department of Diagnostic Radiology, Ultrasound Division, Mayo Clinic Hospital, 200 First Street SW, Rochester, MN, 55905, USA. 9. Department of Diagnostic Radiology, Abdominal Division, Mayo Clinic Hospital, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
Abstract
PURPOSE: Transformation of benign endometriosis to endometriosis-associated ovarian carcinoma (EAOC) is rare; however, women with endometriosis are four times more likely to develop EAOC which can present 20 years earlier than de novo ovarian cancer. Presenting symptoms are often vague and the radiologist's role in recognizing EAOC is critical for early detection and treatment. Histopathologic evaluation remains the mainstay for definitive diagnosis. METHODS: Using a case-based approach, this article will review the sonographic, CT, and MRI features of EAOC with an emphasis on MRI. Histopathologic correlation of benign and malignant endometriosis will be reviewed. RESULTS: Multiple factors contribute to the malignant transformation of endometriosis including genetic alterations, hormonal influences, oxidative stress, and inflammation. Malignancy most often occurs in ovarian endometriomas with less common sites involving the rectovaginal septum, rectosigmoid colon, and abdominal wall scars. The most common pathologic subtypes are endometrioid adenocarcinoma and clear cell carcinoma. MRI is the most specific imaging modality for evaluating EAOC. Key MR features include solid enhancing nodules (accentuated by subtraction imaging), nodular septations, loss of T2 shading within the endometrioma, and diffusion restriction. CONCLUSIONS: EAOC is a distinct disease that affects women with benign endometriosis at younger ages than classic ovarian cancer. Understanding the imaging features of malignant transformation of endometriosis is essential for early diagnosis and timely definitive treatment.
PURPOSE: Transformation of benign endometriosis to endometriosis-associated ovarian carcinoma (EAOC) is rare; however, women with endometriosis are four times more likely to develop EAOC which can present 20 years earlier than de novo ovarian cancer. Presenting symptoms are often vague and the radiologist's role in recognizing EAOC is critical for early detection and treatment. Histopathologic evaluation remains the mainstay for definitive diagnosis. METHODS: Using a case-based approach, this article will review the sonographic, CT, and MRI features of EAOC with an emphasis on MRI. Histopathologic correlation of benign and malignant endometriosis will be reviewed. RESULTS: Multiple factors contribute to the malignant transformation of endometriosis including genetic alterations, hormonal influences, oxidative stress, and inflammation. Malignancy most often occurs in ovarian endometriomas with less common sites involving the rectovaginal septum, rectosigmoid colon, and abdominal wall scars. The most common pathologic subtypes are endometrioid adenocarcinoma and clear cell carcinoma. MRI is the most specific imaging modality for evaluating EAOC. Key MR features include solid enhancing nodules (accentuated by subtraction imaging), nodular septations, loss of T2 shading within the endometrioma, and diffusion restriction. CONCLUSIONS: EAOC is a distinct disease that affects women with benign endometriosis at younger ages than classic ovarian cancer. Understanding the imaging features of malignant transformation of endometriosis is essential for early diagnosis and timely definitive treatment.