Endometriosis - MRI findings with anatomic-pathologic correlation Poster No.: C-2551 Congress: ECR 2015 Type: Educational Exhibit Authors: E. Matos, A. T. Almeida, A. Sanches; Vila Nova de Gaia/PT Keywords: Genital / Reproductive system female, Pelvis, MR, Diagnostic procedure, Education and training, Pathology DOI: 10.1594/ecr2015/C-2551 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 24
Learning objectives To describe and illustrate the different manifestations of endometriosis in magnetic resonance (MR), correlating them with histopathological findings. To contextualize them in the comprehensive knowledge of pathophysiology, clinical manifestation, the value of different diagnostic techniques and treatment. To allow the differential diagnosis with other pathologies, such as hemorrhagic and dermoid cysts, cystic neoplastic lesions of the ovary, namely mucinous and/or hemorrhagic ones. In the infiltrative form, the differential diagnosis with urinary and gastrointestinal pathologies is necessary. Page 2 of 24
Background Epidemiology and Pathophysiology Endometriosis is a frequent gynecological disorder that affects predominantly women of childbearing age. Pathologically it is due to the presence of stromal and glandular endometrial tissue outside the uterine cavity (in an ectopic position). This tissue is responsive to hormonal changes in a similar way as eutopic endometrium. This response gives rise to repeated cycles of hemorrhage that cause an inflammatory response with organizing hemorrhage and fibrosis. Predominantly affects young women although it is a relatively frequent disorder in adolescents - within this group half of the cases are related to mullerian obstructive anomalies of the cervix and vagina. Less frequently can occur in postmenopausal women and men, in which estrogenic replacement therapy seems to play a causative role. The cause is complex, possible multifactorial and only partially understood. Three hypothesis have been mentioned - the metastatic, metaplastic and induction theories. Pathologically endometriosis is characterized by: peritoneal implants, endometriomas and adherences. Peritoneal implants are small foci of peritoneal implantation, ranging from millimeters to few centimeters in diameter (rarely exceeding 3cm) with a variable penetration. They involve more frequently the ovaries but can affect almost any pelvic peritoneal surface or organ or even extra-peritoneal pelvic structures if they are deep. Endometriomas are cystic lesions caused by hemorrhage with consequent inflammation in a deep implant. They are more commonly ovarian and frequently multiple and bilateral. Adherences result from fibrosis and cause compartmentalization of the pelvis with posterior cul-de-sac obliteration. In the deep infiltrative form of the disease there are deep implants (with > 5mm of depth) with sub-peritoneal invasion of fibromuscular and visceral structures. This invasion Page 3 of 24
causes fibromuscular proliferation with nodules/ masses formation and/or abnormal thickening of the involved structures. Clinical diagnosis The clinical diagnosis is difficult due to the lack of specificity of signs and symptoms. Infertility and pelvic pain are the most common symptoms. In the pelvic pain spectrum possible manifestations are dyspareunia, dysmenorrhea, chronic pelvic pain and rectal discomfort. At physical examination, possible signs are: tenderness and/or palpable nodules, masses or abnormal thickening in the posterior cul-de-sac, utero-sacral ligaments or adnexal regions. These signs are frequently absent, and in the majority of cases the clinical examination is non-specific or normal. Complementary diagnostic tests Laparoscopy remains the standard technique for diagnostic and staging, although unable to evaluate subperitoneal involvement. Ultrasonography is important in characterizing endometriomas, despite the difficulty to sometimes differentiate them from other ovarian lesions. MRI depicts the extension of the disease and subperitoneal component, although limited in adhesions evaluation. Complications Possible complications are infertility, malignant transformation and acute cystic rupture. Infertility is believed to be caused, at least partially, by pelvic adherences with tubal occlusion. In the majority of the cases malignant transformation is seen from a previous ovarian lesion. Endometrioid and clear cell carcinomas are the most frequent histologic types and their relationship with endometriosis is well established. Acute cystic rupture a cause of acute abdomen - is rare and more common in pregnant woman. Treatment Medical and surgical treatment options are available, depending on the severity of symptoms and desire of maintaining or restoring fertility. Infertility can be treated surgically and/or with medical reproductive assisted therapies. Pelvic pain is generally treated with hormonal manipulation of the menstrual cycle. In cases of deep infiltrative pelvic endometriosis the standard treatment is surgical with total resection of the lesions Page 4 of 24
and affected structures - consequently it is highlighted the importance of localizing and knowing the extent of lesions before. Page 5 of 24
Findings and procedure details Laparoscopic evaluation Laparoscopy remains the standard method for diagnose and staging, capable of identifying small implants and evaluating the extension of adherences. Staging is done by evaluation of the localization, size and depth of implants; extension and morphologic appearance of adherences and the degree of posterior cul-de-sac obliteration. It is although limited in the evaluation of subperitoneal disease, particularly in sites occulted by adherences. Ultrasonographic evaluation Ultrasonography is the imaging study most frequently sought in a clinical scenario of suspected endometriosis. It has special value in the evaluation and diagnose of endometriomas, being limited in the evaluation of adherences and with variable utility in deep infiltrative disease of the posterior compartment. In the evaluation of an adnexal mass it is sometimes difficult to differentiate an endometrioma from lesions with other nature. MRI evaluation MRI has high diagnostic accuracy; it is non-invasive, with high special resolution and allows a multiplanar evaluation with good characterization of the tissues, without using ionized radiation or iodinated contrast. It is limited in the evaluation of adherences and small implants, for which laparoscopy is better. Table 1. Describes the MRI protocol that is used at our Institution. Table 2. The spectrum of findings of endometriosis with MRI evaluation. Findings are illustrated and described in a series of clinical cases seen at our Institution. Understanding the normal pelvic anatomy is necessary to best comprehend the pathologic findings seen in endometriosis. Commonly affected extra-peritoneal structures are: in the anterior compartment, vesicouterine pouch, urinary bladder, vesicovaginal septum and less frequently the ureters; in the middle compartment, the serosal surfaces of the uterus, the uterine ligaments such as the broad and the round ligaments, the fallopian tube and parametria; and, in the posterior comportment, the retrocervical area, uterosacral ligaments, posterior vaginal fornix, rectovaginal septum, rectum and sigmoid colon - illustrated by Table 3. Page 6 of 24
A definitive diagnosis of endometriosis is done by histopathological evaluation of the lesions. The diagnosis can be however made with a high accuracy by laparoscopy, which remains the standard technique for diagnosis and staging. MRI appears in recent years as a technique with high accuracy for diagnosis and staging, capable of evaluating ovarian lesions, deep solid endometriosis and to a lesser degree pelvic fibrosis. A comprehensive understanding of the histopathological findings aids in the comprehension of those seen with MRI. Histopathological findings are here illustrated and described - based on some clinical cases seen at our Institution. Page 7 of 24
Images for this section: Table 1: MRI Protocol Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 8 of 24
Table 2: Spectrum of findings with MRI evaluation Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 9 of 24
Table 3: Commonly affected extra-peritoneal structures in endometriosis Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 10 of 24
Fig. 1: Bilateral and multiple endometriomas Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 11 of 24
Fig. 2: Infiltrative deep endometriosis of the anterior cul-de-sac involving the bladder and uterus Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 12 of 24
Fig. 3: Multiple endometriomas of the ovary Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 13 of 24
Fig. 4: Multiple and bilateral endometriomas Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 14 of 24
Fig. 5: Endometrioma of the left ovary Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 15 of 24
Fig. 6: Deep solid endometriosis of the anterior compartment involving the anterior culde-sac and bladder Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 16 of 24
Fig. 7: Infiltrative endometriosis of the left ischiorectal fossa Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 17 of 24
Fig. 8: Deep solid endometriosis of the posterior compartment involving the uterosacral ligament Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 18 of 24
Fig. 9: Deep solid endometriosis at the site of previous episiorrhaphy Department of Radiology, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Fig. 10: Histopathological findings of ovarian endometriosis Clinical Pathology Service, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 19 of 24
Fig. 11: Histopathologic findings of a cutaneous lesion of endometriosis Clinical Pathology Service, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 20 of 24
Fig. 12: Histopathological findings in a cutaneous lesion of endometriosis Clinical Pathology Service, Hospital Centre of Vila Nova de Gaia/Espinho, 2014 Page 21 of 24
Conclusion Endometriosis is a frequent disease with serious complications. The clinical diagnosis is difficult. MRI has a high sensitivity and specificity for the diagnosis, to evaluate the extension and complications with high staging accuracy, and aid in the treatment planning process. A comprehensive knowledge of the spectrum of MRI findings is therefore important and achieved firstly by the understanding of the pathology and histopathological characteristics. Recognizing the different MRI findings allows a correct diagnosis and treatment. Page 22 of 24
Personal information E. Matos: MD radiology resident at the Department of Radiology of Hospital Centre of Vila Nova de Gaia/Espinho. A. T. Almeida: MD radiology specialist at the Department of Radiology of Hospital Centre of Vila Nova de Gaia/Espinho. A. Sanches: MD, anatomopathologist and Head of Department of the Service of Clinical Pathology, Hospital Centre of Vila Nova de Gaia/Espinho. Page 23 of 24
References Reviewed bibliography: Woodward P. J., Sohaey R., Mezzetti T. P. 2001. From the Archives of the AFIP Endometriosis: Radiologic-Pathologic Correlation. Radiographics. 21:193-216. Coutinho, A., Bittencourt L. K., Pires C. E., Junqueira F., Lima, C. M. A. O., Coutinho E., Domingues M. A., Domingues R. C., Marchiori E. 2011. MR Imaging in Deep Pelvic Endometriosis: A Pictorial Essay. Radiographics. 31:549-567 Page 24 of 24