Approach to imaging of the ovaries

First encounter Approach to imaging of the ovaries Mariam Moshiri MD Associate professor Body Imaging Most common first encounter is via ultrasound Many of clinicians order US imaging for various female pelvic complaints Therefore we need to start our diagnosfc approach and differenfal diagnosis based on ultrasound appearance of ovarian lesions First encounter differenfal diagnosis Our differenfal diagnosis will be based on the pafents menstrual status DifferenFal diagnosis of ovarian lesions somewhat different for pre vs. post menopausal women DifferenFal diagnosis for adnexal cysfc lesion: premenopausal Follicle (simple, hemorrhagic) Cyst (simple, hemorrhagic) Complex cyst (teratoma, enndometrioma, etc) Neoplasm (benign or malignant) Mullerian anomaly Abnormal pregnancy (ectopic) torsion DifferenFal diagnosis for adnexal cysfc lesion: postmenopausal Cyst (simple, complex) Neoplasm (benign or malignant) Mullerian anomaly Ultrasound Quarterly 2010; 26:121-131 This material should be referred to whenever one decides on further management/imaging recommendafons once an adnexal cysfc lesion is noted on ultrasound The chart is posted in the ultrasound reading room at UW 1

Simple cyst Hemorrhagic cyst Both ovarian and para-ovarian: Round or oval Anechoic Smooth, thin walls No septafons or solid component No internal flow ProducFve age: Less than or equal 5 cm: do nothing Between 5-7 cm: yearly follow up Postmenopausal: Between 1-7 cm: yearly follow up Larger than 7 cm: further imaging (MRI) or surgical evaluafon ReFcular pa^ern with internal echoes Fishnet appearance +/- solid appearing area with concave margins Daughter cyst No internal flow ProducFve age: Less than or equal 5 cm: do nothing More than cm: 6-12 week follow up to ensure resolufon Postmenopausal: Early: follow up unfl resolufon Late: consider surgical evaluafon Make sure there is no flow in the solid component on Doppler Endometrioma Homogeneous low level internal echoes No solid component May have Fny echogenic foci in the wall Focal or diffuse hyperechoic component Hyperechoic lines and dots Area of acousfc shadowing No internal flow Dermoid Any age: IniFal follow up 6-12 week, then yearly Any age: if not removed surgically, yearly follow up Tubular shaped cysfc structure Beads on string sign Waist sign Cogwheel sign Separate from ovary Hydrosalpinx Peritoneal inclusion cyst Follows the contours of the pelvis and adjacent structures Ovary at the edge of the mass or suspended from it May have septafons 2

No classic findings Findings not classic for hemorrhagic cyst, or endometrioma, or dermoid ProducFve age: 6-12 week follow up, if unchanged not likely hemorrhagic cyst Follow up with US or MRI If no diagnosis, consider surgical evaluafon CharacterisFcs worrisome for malignancy Thick irregular spetafons Nodule with blood flow Postmenopausal: Surgical evaluafon Consider surgical evaluafon Ovarian neoplasms Pa^ern of disease spread Serous Stromal Invasive Mucinous Surface epithelial Non-invasive Endometroid Germ cell Brenner : benign About 90% of ovarian cancers arise from the ovarian surface epithelium All peritoneal spaces communicate freely Malignant cells shed from the surface of the into the peritoneal cavity Peritoneal seeding is the most common mode of spread Peritoneal fluid is in constant circulafon by gravity and hydrostafcs Clear cell carcinoma UndifferenFated Pa^ern of disease spread Tumor cells spread by following the normal flow pa^ern of peritoneal circulafon Certain sites are favored due to relafve stasis They include: The flow pa^ern facilitates metastases within the peritoneal cavity Tumor cells may fall into cul-desac by gravity Tumor cells tend to flow along the paracolic gu^ers Rectouterine pouch Paracolic gu^ers Inferior extent of the small bowel mesentery in the right iliac fossa Morrison s pouch 3

Routes of disease spread They ogen coexist Tumor cells spread by following the normal flow pa^ern of peritoneal circulafon Direct spread along reflecfons LymphaFc spread Tumor emboli spread via the superior mesenteric artery and deposit on the anfmesenteric border of the bowel Intraperitoneal seeding Hematogenous embolic spread PreferenFal flow and seeding along the right paracolic gu^er, liver capsule and right hemidiaphragm Other common sites: Cul-de-sac Greater omentum Paracolic gu^ers CT images from leg to right and corresponding PET/CT: Subcapsular implant Mesenteric implant Omental caking Other common sites: Bowel surface seeding Liver capsule surface Subphrenic space through the round LymphaFc drainage pathway Main Pathway: LymphaFcs that follow the ovarian veins to para-aorfc and aortocaval lymph nodes through the broad through the round LymphaFc drainage pathway Main Pathway: LymphaFcs that follow the ovarian veins to para-aorfc and aortocaval lymph nodes through the broad Hematogenous spread Local extension to adjacent organs Least common at inifal presentafon More common at restaging Common sites: Liver, lung, adrenal glands, spleen, bone, brain Other sites: bladder Commonly involves uterus and fallopian tubes Other sites: rectum 4

Ovarian cancer staging Staging group TNM staging FIGO staging Ia T1aN0M0 IA Ib T1bN0M0 IB Ic T1cN0M0 IC IIa T2aN0M0 IIA IIb T2bN0M0 IIB IIc T2cN0M0 IIC Staging is performed by imaging as well as surgically DifferenFaFon between stage III and IV disease has direct impact on pafent management Ovarian cancer staging Presence of nodal metastases is an important prognosfc factor Stage III treated primarily by surgical debulking Stage IV treated primarily by chemotherapy and cytoreducfon IIIa T3aN0M0 IIIA IIIb T3bN0M0 IIIB IIIc T3cN0M0 Any TN1M0 IIIC IV Any T any N M1 IV Ovarian cancer staging Pleural effusion could be benign; Pleural effusion with pleural thickening or nodularity very likely malignant; may require thoracentesis to characterize PotenFal piialls in assigning FIGO stage IV disease Maybe difficult to differenfate between liver surface implants and true liver metastases, sagi^al/coronal reformates can be helpful Role of imaging in staging: CT Not very sensifve for characterizafon; Used for primary staging Very useful in determinafon of extent of and ancillary findings Role of imaging in staging: MRI T1WI, mulfplanar T2WI, and fat-sat T1WI with and without contrast are necessary Solid or cysfc adnexal mass Abnormal MRI Ascites, omental caking Very useful in characterizafon, determinafon of extent of, and ancillary findings Mural nodules, heterogeneous mass, necrosis Solid or cysfc adnexal mass Abnormal CT Ascites, omental caking Mural nodules, heterogeneous mass, necrosis Role of imaging in staging: PET/CT Brenner Uptake of 18-FDG in the normal ovaries limits use for detecfon of primary Uptake in benign lesions such as dermoid, corpus luteum and cystadenoma limits detecfon of primary While evaluafng primary, differenfafon of benign from malignant lesion on 18-FDG PET alone is not possible 18-FDG PET needs to be correlated with a diagnosfc CT or MRI examinafon Epithelial 30% associated with another epithelial of the ovary Solid mass on US T1 and T2 low SI Uptake in the ovaries of postmenopausal pafent is considered suspicious PET/CT imaging has a more important role in surveillance and restaging of ovarian carcinoma 5

Fibrothecoma Sex cord/stromal Can secrete estrogen Maybe hypoechoic on US with some shadowing or just a non specific solid mass T1 low SI, T2 low SI Criteria indicafve of PCOS Increased ovarian size more than 10cc, can be unilateral 12 or more follicles measuring 2-9mm, can be unilateral Follicles of similar size with peripheral locafon String of pearl sign Hyerechoic centeral stroma FerFl Steril 2004; 81:19-25 6