Pelvic inflammatory disease (PID) is a common affliction. In North America, it is usually caused by sexually transmitted neisseria gonorrheae or chlamydia trachomatis. Risk factors for contracting this disease include multiple sexual partners and intrauterine contraceptive devices; sexually active young women are at greater risk than are older women.

The disease presents with pelvic pain, fever, dyspareunia, and vaginal discharge; lower abdominal and cervical tenderness are common. Long-term complications include infertility and ectopic pregnancies. The disease may cause endometritis, salpingitis, oophoritis, pyosalpinx, tubo-ovarian abscesses, and local peritonitis. Occasionally, inflammation may spread to the right upper quadrant (Fitz-Hugh-Curtis syndrome). Late pathologic consequences include hydrosalpinx, salpingitis isthmica nodosa (SIN), pelvic adhesions, and, especially if there has been intrauterine instrumentation, endometrial synechiae (Asherman syndrome).

Most patients are treated successfully with antibiotics. A minority require image-guided interventional procedures, which may be performed percutaneously, transvaginally, or transrectally. Occasionally, formal surgery is required to resect a chronically inflamed tubo-ovarian abscess with pyosalpinx.

Radiography and urography have no place in the work-up of PID and are used only when the clinical picture requires other conditions to be excluded.

Ultrasound is the mainstay of imaging diagnosis. It may extend the findings of physical examination in acute PID: palpation of the cervix with an endovaginal probe may elicit severe tenderness. Imaging findings are variable; some patients with acute PID have no definite ultrasound abnormalities. Intrauterine abnormalities may be encountered: the endometrial stripe may be distorted or difficult to see, and there may be a small amount of fluid in the cavity. The uterus may be slightly enlarged. The fallopian tubes may be thickened without a visible lumen, or if pyosalpinges have appeared, they may be distended with fluid; the lumen may contain low-level echoes or fluid-debris levels (Fig. 18.1). One or both ovaries may be enlarged. If a tubo-ovarian abscess has appeared, a fluid-filled lesion arising from the ovary may be visualized. This may be unilocular or multilocular, may have a thick wall, especially if the abscess is acute, and may demonstrate a fluid-debris level. Inflamed fallopian tubes and ovaries may produce a number of appearances; combinations of swelling and complex cystic masses with thick and thin walls may be encountered. When no discrete fluid collection is seen, the lesion may have a mass-like appearance; when the lesion has both cystic and solid components, it may be called a tubo-ovarian complex rather than a tubo-ovarian abscess. Additional signs suggesting inflammation include the inability to demonstrate free sliding motion at the interfaces between the uterus or adnexa and adjacent pelvic viscera. There may also be fluid in the cul-de-sac.

Remote bouts of PID may produce sonographically visible chronic abscesses or hydrosalpinges; these are less likely to be tender or to have echogenic debris in their internal fluid and usually have thinner walls than do the acute varieties. Occasionally, endometriosis may obstruct the tubes and cause hydro- or hematosalpinges. There are several entities that produce cystic adnexal lesions; hydrosalpinges may be differentiated from them by their tubular shape, by the occasional demonstration of mucosal folds, and by the “waist” that is often seen at their ends. Other fluid-filled tubular structures near the uterus include fluid-filled bowel loops and blood vessels; observation of peristalsis, and of blood flow by Doppler sonography, usually distinguishes these. Pelvic adhesions may also appear following PID; these are often not detected by ultrasound but may produce blurring of the margins of the ovary and adherence of the ovary to the surface of the uterus. Abscesses that have originated from intestinal abnormalities such as appendicitis and diverticulitis may be difficult to distinguish from tubo-ovarian abscesses.

Computed tomography (CT) is not a first-line technique for investigating patients with possible PID. Nevertheless, it may be performed when conditions like appendicitis are suspected. Endometritis seldom is detected unless cervical obstruction is present. Inflammation of the ovaries and tubes may be demonstrated by inflammatory infiltration of adjacent fat; when visible, thickening of the tubes is an accurate indicator of salpingitis (Fig. 18.2). Pyosalpinges or hydrosalpinges may be demonstrated as fluidfilled structures adjacent to the uterus. Fluid-filled fallopian tubes may be identified as such by following them to the cornua; these may be distinguished from other cystic adnexal lesions because they are frequently tortuous and tubular rather than spherical. Tubo-ovarian abscesses appear as fluid-filled adnexal lesions: acute abscesses (Fig. 18.3) are usually unilateral and multilocular; they usually have thick walls and adjacent inflammatory changes in the fat, whereas chronic ones are usually thinner walled and have fewer inflammatory changes. Bubbles of gas in tubo-ovarian abscesses are extremely rare, so that when they are encountered,
strong consideration should be given to an abscess of enteric origin. Sometimes, adnexal inflammatory disease does not produce clear fluid collections but may appear as ill-defined thickening of the fallopian tubes and ovaries; under such circumstances, a specific diagnosis is often quite difficult. If the Fitz-Hugh-Curtis syndrome occurs, CT may demonstrate thickening of the anterior hepatic capsule, abnormal enhancement of the capsule and adjacent hepatic tissue, and signs of gallbladder inflammation.

FIGURE 18.1. Pyosalpinx. A: Transvaginal ultrasound shows a distended curved tube. B: Transvaginal ultrasound of a more dependent portion of the tube reveals intraluminal debris. C: CT also reveals the dilated left fallopian tube; a small portion of the dilated right tube is visible as well.

FIGURE 18.2. A, B: PID. Two CT images demonstrate a thickened left fallopian tube (arrows).

Magnetic resonance imaging (MRI) is probably more accurate than other techniques in demonstrating PID. It reveals purulent fluid in tubo-ovarian abscesses or pyosalpinges, which has the same appearance as pus elsewhere. The fluid is usually of low intensity on T1-weighted images and bright on T2-weighted images (Fig. 18.4). Occasionally, endometriosis may complicate the inflammatory changes, so that the fluid may be bloody and appear bright on T1-weighted images. Inflamed walls of the fallopian tubes or abscesses enhance with gadolinium on T1-weighted images.

The serpiginous course of fluid-filled obstructed fallopian tubes may be particularly well demonstrated by MRI if multiple imaging planes are used. Small series have suggested that MRI is more sensitive than ultrasound—even transvaginal ultrasound—in depicting these changes.

FIGURE 18.3. Tubo-ovarian abscess. Contrast-enhanced CT (A) reveals the enhancing uterus to be displaced anteriorly and laterally by a septated fluid-filled thick-walled lesion. Tranverse ultrasound with color Doppler (B) shows a cystic debris-containing abscess with strong mural flow. (Courtesy of Sherelle Laifer-Narin, M.D.)

FIGURE 18.4. Bilateral hydrosalpinges. T2-weighted MR images reveal convoluted distended fallopian tubes filled with high-intensity fluid.

Hysterosalpingography is contraindicated as an imaging technique during acute bouts of PID. But the technique is often used in an infertility work-up of patients who have had PID in the past and may reveal various abnormalities. The tubes may be occluded and fail to opacify. Alternatively, the distal ends of the tubes may be occluded, so that the tubes fill and distend during injection, but do not spill contrast into the peritoneum (Fig. 18.5). Not infrequently, there is a discrepancy in the degree of hydrosalpinx demonstrated by hysterosalpingography and by other techniques. A fallopian tube that is occluded at two points, and that is distended in between, may appear as a hydrosalpinx on noninvasive imaging but fail to opacify at all on hysterosalpingography. Alternatively, a distally occluded tube may be transiently distended during hysterosalpingography but appear of normal diameter when other techniques are used.

Hysterosalpingography is insensitive in diagnosing pelvic adhesions, but when extensive adhesions are present, certain abnormalities may appear. Contrast may not spill from the fimbriated end or, if it spills, may fill a loculated and relatively fixed cavity rather than spread freely throughout the peritoneal space of the pelvis (Fig. 18.6).

FIGURE 18.5. Bilateral hydrosalpinx. The ampullary portions of the fallopian tubes are dilated, and there is no peritoneal spill.

FIGURE 18.6. Pelvic adhesions from PID. Hysterosalpingographic contrast spills from the fimbriated end of the left tube and fills a large irregular cavity (star); there is no free flow within the peritoneum. The right tube is obstructed; the endometrial cavity is normal.

Chronic inflammation of the fallopian tubes may lead to SIN. This condition is diagnosed with salpingography. Multiple tiny diverticulae are seen, which fill from the lumen of the tube (Fig. 18.7). The diverticulae usually occur in clusters rather than being uniformly distributed along the tube and are most frequently encountered in the isthmus adjacent to the interstitial portion of the tube. The diverticulae are cavities in small nodules of postinflammatory tissue, which may be visualized laparoscopically and palpated. They frequently appear along with other hysterosalpingographic evidence of prior inflammatory disease, such as tubal occlusion and hydrosalpinx. SIN is associated with decreased fertility and an increased likelihood of tubal ectopic pregnancy.

Nuclear medicine has not played a large role in diagnosing PID, but scintigraphy using tagged leukocytes may demonstrate the inflamed structures.


Ovarian Neoplasms

Ovarian tumors are composed of a wide variety of types. Although they are not the most common gynecologic malignancy, they cause more deaths than any other primary gynecologic tumor because they are so often asymptomatic until they have reached an incurable stage, and because widespread effective screening has yet to be developed.

There are several groups of primary ovarian tumor types; in descending order of frequency, these are epithelial tumors, germcell tumors, sex cord-stroma tumors, and gonadoblastoma. Other malignancies may metastasize to the ovary as well.

Among the epithelial tumors, serous cystadenomas and cystadenocarcinomas are relatively common, as are mucinous cystadenomas, cystadenocarcinomas, and endometrioid tumors. In this group, the majority are benign; a smaller proportion are of borderline malignancy, and a yet smaller fraction are clearly malignant. Brenner tumors and clear-cell epithelial cell tumors are seen less often.

Germ-cell tumors are composed of dermoid tumors or benign cystic teratomas. They contain a combination of endo-, meso- and ectodermal tissues, including teeth, hair, and oily, sebaceous, or fatty material and neural tissue. Malignant teratomas are less common, and squamous-cell carcinoma is even rarer. Dysgerminomas are an uncommon variety of germ-cell tumor. Yolk sac, or endodermal sinus, tumors are also rare, as are choriocarcinomas. Ovarian tumors encountered in children are most likely to be germ-cell tumors.

FIGURE 18.7. SIN. Hysterosalpingogram reveals multiple small nodular diverticula (arrows) arising from the isthmic portions of the tubes. There are adhesions; no free intraperitoneal spill is seen.

The least frequently encountered group of primary ovarian tumors are the sex cord-stroma tumors, types of which include the fibroma-thecoma, granulosa-cell tumor, and Sertoli-Leydig cell tumor.

Extraovarian malignancies may metastasize to the uterus. Breast carcinoma and lung carcinoma may do so, as may adenocarcinoma of the stomach or colon. The term Krukenberg tumor originally was applied to metastases that consisted of epithelial tissue with a specific signet-ring appearance of individual cells; the term is now sometimes used to denote any tumor metastatic to the ovary. Primary epithelial carcinomas of one ovary frequently appear on the contralateral one as well.

Many primary ovarian tumors remain asymptomatic for a lengthy period. Local symptoms from mass effect may occur; abdominal swelling or bloating or a sensation of pelvic fullness may be reported, or the tumor itself may be palpated. Uncommonly, dyspareunia is encountered; large masses may produce pain. Symptoms caused by ascites or pleural effusions may occur in late-stage cancer. Ovarian tumors may undergo torsion and cause severe pelvic or lower abdominal pain. Late-stage tumors may cause bowel obstruction. Meigs syndrome, which is classically described but infrequently encountered, includes ascites and a right pleural effusion, which accompany an ovarian fibroma.

Some tumors secrete hormones and other substances that help establish the diagnosis. Estrogen may be secreted by granulosa-cell and theca-cell tumors, which leads to precocious puberty in girls, or signs of postmenopausal bleeding in older women; these tumors have even produced virilization. There may be effects of estrogen on target tissues, including postmenopausal endometrial hyperplasia, endometrial carcinoma, or changes in the glandular tissue of the breasts. Sertoli-Leydig cell tumors may lead to virilization as a result of production of testosterone. Tumors may also secrete detectable substances that are clues to their diagnosis or to their posttherapy recurrence. These include CA-125, which is elevated in
about four-fifths of patients with epithelial ovarian malignancies; human chorionic gonadotropin, which can be secreted by choriocarcinoma and embryonal cell carcinoma; and elevated levels of alpha-fetoprotein, which may be secreted by embryonal cell and endodermal sinus tumors.

Mucinous adenocarcinomas of the ovary, like certain mucinous tumors elsewhere in the abdomen, may spread throughout the peritoneal cavity, so that widespread mucin production fills the peritoneal cavity with a jelly-like substance. This condition is called pseudomyxoma peritonei and may produce abdominal enlargement, bloating, pain, and even bowel obstruction.

The biology of the tumors has frustrated the development of screening measures; tests that are sufficiently accurate and inexpensive have been hard to find. To date, attention has focused on screening ultrasound and determinations of serum CA-125. Ultrasound is not inexpensive, especially when combined with transvaginal examination and reveals many ovarian space-occupying lesions that ultimately are shown to be benign. CA-125 is elevated in most epithelial ovarian cancers but is also increased in other cancers, including those of breast, colon, and pancreatic origin. CA-125 may also be elevated as a result of nonneoplastic disease, which in turn may be gynecologic (endometriosis, adenomyosis, fibroids), nongynecologic (cirrhosis, diverticulitis), and even physiologic (pregnancy). These factors make general screening ineffective. To date, there is no strongly supported indication that there is a subset of patients for whom screening might be worthwhile. Having first-degree or second-degree relatives with the disease increases the risk, as does nulliparity. Carcinoma of the breast doubles the risk of acquiring ovarian cancer, and a family history of endometriosis or some colon tumors increases the risk. Possessing the BRCA1 or BRCA2 gene confers particularly high risk. Investigation continues to determine whether screening may be worthwhile in high-risk groups. If screening is performed, a combination of CA-125 and ultrasound (preferably transvaginal) should be performed. If both are abnormal, the chances that the affected patient has ovarian carcinoma are markedly elevated; elevated CA-125 in the face of normal ovarian morphology does not seem to increase the likelihood of having ovarian cancer. Although preliminary data suggest that life expectancy may be improved by a carefully tailored screening program, a reliable conclusion is not yet possible; even cancers detected by screening are often advanced.

Staging of ovarian cancer is crucial, both for prognosis and treatment. The currently used system is that adopted by FIGO: the staging system (Table 18.1) depends primarily on initial operative, rather than imaging, findings.

Initial treatment of ovarian cancer nearly always is surgical. Usually, the patient has a total abdominal hysterectomy and bilateral salpingoophorectomy. Only in very rare circumstances, in which there is a small tumor clearly limited to one ovary, the uterus and other ovary may be left to permit fertility. Surgery includes widespread abdominal and pelvic exploration to seek peritoneal implants and peritoneal washing to search for exfoliated cells from metastases. If there is extensive abdominal disease, a debulking procedure is performed in which as much tumor is removed as possible.

Except for the most localized of disease, the majority of patients receive postoperative chemotherapy. At an interval after chemotherapy, a “second-look” laparotomy is sometimes performed for disease assessment, but PET-CT and CA-125 follow-up studies have rendered the utility of this operation questionable.

Radiography and urography are not used deliberately to detect ovarian cysts, although large benign or malignant cysts may be directly visible as pelvic masses, and ascites may be detectable. Any pelvic space-occupying lesion, if sufficiently large, may cause ureteral obstruction. Occasionally, small bowel or barium enema examinations reveal metastatic ovarian carcinoma as mural masses in the gut; enteric metastatic disease occasionally produces bowel obstruction.

TABLE 18.1 Staging of Ovarian Carcinoma

Tumor Limited to the Ovaries

Stage I

  1. One ovary

  2. Both ovaries

  3. One or both ovaries, with ruptured capsule and/or malignant cells in ascites or peritoneal washings

Stage II

Pelvic extension

  1. Tumor on surface of uterus and/or tubes

  2. Tumor on surface of other pelvic organs

  3. Tumor on surface of uterus or tubes or other pelvic organs, with malignant cells in ascites or peritoneal washings.

Stage III

Ovarian tumor with extra-pelvic peritoneal tumor and/or retroperitoneal and/or inguinal nodes and/or serosal implants on abdominal viscera.

  1. Negative nodes; microscopic abdominal peritoneal implants

  2. Negative nodes; macroscopic abdominal implants >2 cm in diameter

  3. Abdominal serosal implants >2 cm and/or retroperitoneal or inguinal nodes

Stage IV

Distant metastases and/or malignant pleural effusions, and/or intraparenchymal hepatic metastases

FIGURE 18.8. Serous cystadenoma. Transabdominal ultrasound reveals a multilocular cystic tumor with a dependent layer of debris (arrow).

Ultrasound is the primary imaging modality for the detection of cystic ovarian lesions, although CT and MRI can demonstrate them as well. Cystadenomas have ultrasound characteristics similar to those of simple cysts elsewhere in the body. The fluid is usually anechoic and produces enhanced through-transmission; occasionally, hemorrhage or other debris may appear as low-level echoes in the dependent portion (Fig. 18.8). The lesions are circular or ovoid and the wall is thin; in cystadenomas, regions of solid tissue should not be detectable. Cystadenomas occasionally have septi, but they
are few and thin. Calcification is unusual. Demonstration of clearly normal ovarian tissue at the margin of a cystic mass strongly suggests that the mass is not malignant.

FIGURE 18.9. Two cases of cystadenocarcinoma. A: Transabdominal ultrasound reveals a cystic lesion with irregular wall and mural nodule. B: Transvaginal ultrasound demonstrates nodule of solid tumor. (Courtesy of Nancy Budorick, M.D.)

FIGURE 18.10. Serous cystadenoma. This large lower abdominal mass has very thin walls and septae. (Courtesy of Nancy Budorick, M.D.)

Cystadenocarcinomas tend to have regions of viable solid tissue (Fig. 18.9); this may appear as regions of thickening in the wall or thick septi (which may be more numerous than those seen in cystadenomas) or as papillary nodules within the wall or projecting into the cystic region. Occasionally, adenocarcinomas may consist primarily of solid perfused tissue and have only small cystic regions within them. The fluid within mucinous cystadenocarcinomas tends to have more echoes within it than the fluid in serous cystadenocarcinomas.

Doppler ultrasound contributes a great deal of information that is of value in distinguishing benign from malignant cystic lesions. Color and power Doppler images tend to show more flow in malignant tissue. The pulsatility index or the resistive index often shows low-impedance flow through the solid tissue. Various authors have suggested different thresholds of these indices for distinguishing benign from malignant lesions. Malignant tumors are much more likely to have Doppler-detectable flow in central regions, whereas both benign and malignant lesions may demonstrate peripheral flow. Doppler indices are far from perfect in distinguishing benign from malignant lesions, however. Even nonneoplastic vessels whose muscular walls are dilated will produce relatively low pulsatility and resistive indices, so that the inflammatory tissue in the margins of some tubo-ovarian or other abscesses may mimic the Doppler pattern of malignancy, as may flow in the margins of rapidly changing or hemorrhagic corpus luteum cysts or even in some dermoids.

In widespread intra-abdominal disease, ultrasound may also provide valuable information. Ascites is frequently demonstrable, as are cystic masses of the serosal surfaces of the gut, omentum, or upper abdominal viscera; occasionally, enlarged pelvic lymph nodes or hepatic metastases may be demonstrable as well. In patients in whom widespread mucinous adenocarcinoma has caused pseudomyxoma peritonei, ultrasound may reveal a large amount of intraperitoneal material, which is of low echogenicity and avascular. No technique is very sensitive, either initially or after therapy, for small peritoneal implants.

CT of ovarian cystadenomas reveals findings similar to the ultrasound features. The lesions are usually of water density although they may be denser because of hemorrhage, and their central portions do not enhance. The walls are very thin and enhancement of them may be minimal (Fig. 18.10). They are ovoid or spherical, and contain no internal papillary projections or vegetations and no enhancing solid components. There may be curvilinear calcification in the wall. There is no size threshold that clearly separates cystadenomas from cystadenocarcinomas, but malignant tumors tend to be larger than benign ones. Lesions smaller than 5 cm in diameter and that have no thick-wall segments or solid components are very likely to be benign.

Cystadenocarcinoma produces CT findings qualitatively similar to the ultrasound ones. The walls of the cystic portions may be thicker, either focally or circumferentially, and the central portions of the tumor may contain solid enhancing nodular regions (Fig. 18.11); occasionally, the solid tissue will predominate, or the tumor may even be completely without cystic areas. When seen on CT, the tumors usually are larger than 5 cm in diameter and may reach a huge size, becoming more than 20 cm in diameter. The solid portions may calcify.

FIGURE 18.11. Ovarian cystadenocarcinoma. CT demonstrates a large cystic lesion that has several thick septae and regions of solid viable tissue.

Intra-abdominal metastatic disease has various patterns (Figs. 18.12 and 18.13). Tumor nodules may be seen on the parietal peritoneum or on the serosal surface of any portion of the gut or on the surface of the liver or spleen. Lymph node enlargement suggests involvement with metastatic disease; the first nodes to enlarge may be at the level of the renal hilus rather than in the pelvis. More widespread intraperitoneal metastases may be demonstrated by generalized thickening and infiltration of the omental fat (omental “caking”) or as extensive areas of heterogeneous solid tissue anywhere in the peritoneal cavity. Focal metastatic lesions of the liver or spleen are usually late manifestations and nearly always appear on the surfaces of the organs rather than entirely within the parenchyma; they are usually cystic with solid components and enhancing rims. Metastases may calcify. Ascites is frequently seen with disseminated disease, and pleural effusions may occur as well. Lung metastases appear late.

FIGURE 18.12. Recurrent ovarian carcinoma. A: Ultrasound reveals multicystic mass with debris in the fluid and regions of solid tissue. B: Doppler waveform reveals low-impedance flow in a solid tissue nodule.

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Oct 7, 2016 | Posted by in GENERAL RADIOLOGY | Comments Off on Ovaries
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