Differentiation of Tuboovarian Abscess from Endometriosis: CT Indicators

PURPOSE: To assess and compare CT findings of surgically confirmed cases of tuboovarian abscesses (TOA) and endometriosis in order to identify indicators which may be helpful in making correct preoperative diagnoses. MATERIALS AND METHODS: Of the 35 consecutive patients with surgically confirmed TOA, CT images were available for 11 of those patients. As a comparative group, 36 patients with surgically confirmed endometriosis with CT images were selected. CT images of TOA were compared with those of endometriosis. A retrospective analysis of the CT images of both groups was performed without knowledge of the pathologic diagnosis. The analysis compared the thickness and enhancement pattern of the cyst wall, attenuation of the cyst content, size and shape of the cyst, and paraaortic lymphadenopathy. RESULTS: Mean thickness of the cyst wall was 6.2+/-2.0 mm in TOA and 4.5+/-2.4 mm in endometriosis. Multilayered appearance in both diseases was seen on enhanced CT in 91% (10/11) of TOA cases and in 25% (9/36) of endometriosis cases. Hounsefield units of the cyst contents were 20.0+/-5.5 HU and 24.7+/-10.0 HU for TOA and endometriosis, respectively. Mean diameter of the cysts was 7.5+/-1.7 cm in TOA and 7.9+/-3.1 in endometriosis. Shape of the cyst was multilocular in 82% (9/11) of TOA cases and in 75% (27/36) of endometriosis cases. Paraaortic lymphadenopathy was present in 73% (8/11) and 44% (16/36) for TOA and endometriosis, respectively. CONCLUSION: TOA should be suspected on CT when a multilocular cystic ovarian mass is observed, especially if the lesion has a thick wall and has a multilayered appearance, and is accompanied by paraaortic lymphadenopathy.

Sclerosing Stromal Tumor of the Ovary: A Case Report

Sclerosing stromal tumor of the ovary is a rare benign neoplasm, with distinctive clinical and pathologic features. It occurs predominantly in females during the second and third decades of life. Histologically, it is composed of cellular and acellular collagenized areas, and edematous stromal areas, and at ultrasonography and computed tomography is seen as a distinctive mixed solid and cystic mass lesion. We report a case of sclerosing stromal tumor of the ovary in a 15-year-old girl with a history of menorrhagia since menarche. Ultrasonography revealed the tumor as a well-defined, lobulated, heterogenous echogenic pelvic mass, while at CT, a huge pelvic mass 9x9x10 cm in size, was seen. This comprised a well-enhanced internal solid portion, a capsule, septa, and a non-enhanced cystic portion.

Primary Ovarian Leiomyoma with Cystic Degeneration: A Case Report

Leiomyoma of the ovary is a very rare benign tumor which is usually found incidentally on routine pelvic examination, or during surgery or autopsy. We report a case of ovarian leiomyoma in a 46-year-old woman in whom a lower abdominal mass was detected. A multiloculated and multiseptated mainly cystic mass in the left adnexa was revealed by computed tomography, and was thought to be an ovarian mucinous cystadenoma. Surgical pathology, however, demonstrated that the mass was a vascular leiomyoma originating from the left ovary.

Radiologic Findings of Ovarian Fibrothe

PURPOSE: To evaluate the radiologic features of fibrothecoma of the ovary, which is a rare solid tumor originating from the ovarian sex cord-stroma. MATERIALS AND METHODS: The radiologic findings of 29 patients with pathologically-proven fibrothecoma of the ovary were retrospectively evaluated for bilaterality, size, shape, margin, echogenecity, CT attenuation, signal intensity on magnetic resonance imaging, calcification, and amount of ascites. RESULTS: All fibrothecomas were unilateral, and had well defined margins. The diameter of the mass was 4-18(mean, 9.6)cms. Elghteen of 29 tumors were round or oval with a smooth margin, and eleven were lobulated. The internal architecture of the tumor was purely solid in 21 patients, predominantly solid in six, and pre-dominantly cystic in two. A broad spectrum of sonographic features was apparent, including a homogeneously hypoechoic mass (with posterior shadowing in four cases, and without posterior shadowing in ten), a homoge-neously hyperechoic mass in seven cases, an anechoic mass with septatations in two, and a mixed echoic mass in six. On precontrast CT scans, the mass was isodense to the uterine myometrium in eight of nine cases, while on postcontrast scans the lesion was slightly hypodense to the myometrium in seven cases and isodense in one. On T1-weighted MR images, nine of ten cases showed a relatively homogeneous low signal intensity, while on T2-weighted images, signal intensity was homogeneously low in two patients and predominantly low with focal high intensity in seven of the other eight. On gadolinium-enhanced T1-weighted images, most tu-mors showed slight heterogeneous enhancement. Calcifications were present in two cases, and in two others there was a large amount of ascites. CONCLUSION: The characteristic finding of ovarian fibrothecomas is a well-defined, oval or lobulated homoge-neously solid mass, which on CT scans enhances less than uterine myometrium and demonstrates a predomi-nantly low signal intensity on both T1- and T2-weighted images. However, a predominantly solid mass with cystic components or a predominantly cystic mass may also be presented.

CT Findings in Differential Diagnosis of Pelvic Inflammatory Bowel Mass and Tuboovarian Abscess

PURPOSE: To evaluate the CT findings which may help differentiate pelvic inflammatory bowel mass(IBM) fromtubo-ovarian abscess(TOA). MATERIALS AND METHODS: Twenty-five patients with histologically confirmed TOA(n=14),periappendiceal abscess(n=9), an abscess caused by diverticulitis(n=1), and by ulcerative colitis(n=1) wereevaluated. For TOA, age distribution ranged only from the 3rd to the 5th decade, but for IBM, the range was the 2nd to 8th decade with highest frequency during the 3rd-4th decade. CT findings were retrospectively analysed forbilaterality, internal septa, anterior displacement of the mesosalpinx, and perirectal and mesenteric fat. RESULTS: Mesenteric fat infiltration was detected in all 11 cases of pelvic IBM, but in only two of 14 TOA cases(p<0.05).Anterior displacement of the mesosalpinx was observed in two of 11 pelvic IBM cases and in nine of 14 TOAcases(P<0.05). There were no significant difference in bilaterality, internal septa, or perirectal fatinfiltration. CONCLUSION: Mesenteric fat infiltration was the most reliable finding in differentiating pelvic IBMform TOA. Anterior displacement of the mesosalpinx, and age distribution were also helpful in differentiating thetwo disease groups.

CT Differentiation of Solid Ovarian Tumor and Uterine Subserosal Leiomyoma

PURPOSE: On the basis of CT findings, to differentiate between solid ovarian tumor and uterine subserosalmyoma. MATERIALS AND METHODS: In eight surgically proven cases of solid ovarian tumor and in ten uterinesubserosal myoma patients, contrast-enhanced CT images were obtained. Two genitourinary radiologists reviewed thefindings with regard to degree of enhancement of the mass as compared with enhancement of uterine myometrium,thickening of round ligaments, visualization of normal ovaries, contour of the mass, and the presence of ascitesin the pelvic cavity. RESULTS: Six of eight ovarian tumors but only two of ten uterine myomas were less enhancedthan normal uterine myometrium (p 0.05). The contour of themass was lobulated in two of eight ovarian tumor patients, but in five of ten uterine myoma patients (p>0.05). CONCLUSION: CT findings suggestive of solid ovarian tumor were less contrast enhancement of the mass than ofnormal uterine myometrium, pelvic ascites, and nonvisualization of normal ovary.

CT Differentiation of Ovarian Mucinous and Serous Cystadenocarcinoma

PURPOSE: To assess the differences between imaging findings of mucinous and serous cystadenocarcinomas of the ova r y, as seen on computed tomography (CT). MATERIALS AND METHODS: The CT findings of 24 patients with mucinous cystadenocarcinoma (25 tumors) and 26 with serous cystadenocarcinoma (47 tumors) of the ovary were retrospectively analysed. Images were evaluated for tumor size, contour, CT attenuation of locules within the mass, the presence of septal vegetation, the proportion of solid portion within the mass, the presence of calcification, and carcinomatosis peritonei. RESULTS: Mucinous cystadenocarcinomas tend to have a smooth contour (96%), variable CT attenuation of locules (80 %), and even size of locules within the mass (88.0%). Serous cystadenocarcinomas, on the other hand, tend to have an rregular lobulated contour (89.4 %), unevenly sized locules (76.6%), septal vegetation (57.4 %), and a prominent solid portion (59.6%). Bilaterality and carcinomatosis peritonei were more common in serous than in mucinous cystadenocarcinoma. CONCLUSION: Features which are valuable for the differentiation of mucinous and serous cystadenocarcinomas of the ova r y, as seen on CT, are tumor size, contour, varying locule attenuation and size, septal vegetation, a solid portion, bilaterality and peritoneal seeding.

Radiologic Findings of Ovarian Borderline Malignancy

PURPOSE: Ovarian epithelial tumors of borderline malignancy belong to a disease entity distnct from that ofbenign and overt malignant tumors, and the younger age of patients and earlier stage at diagnosis compared withinvasive ovarian cancers makes conservative surgery an important issue. The purpose of this study was to evaluatewhether there are any characteristic radiologic findings to suggest the presence of these tumors. MATERIALS AND METHODS: In 20 pathologically proven tumors of ovarian borderline malignancy, the findings of ultrasonography (n= 17) (with color Doppler ultrasonography in two cases), computed tomography (n = 8), or magnetic resonanceimaging (n = 6) were compared with pathologic findings and, were retrospectively reviewed and analyzed. Imageswere evaluated for size, loculation, thickness and regularity of wall and septum, endocystic vegetation, solidportion, calcification, local invasion and distant metastasis. RESULTS: Among 20 unilateral tumors, 18 weremucinous and two were serous; 19 (95%) were at stage I, and one was at stage II (local invasion of uterus, leftpara-aortic lymphadenopathy, and malignant ascites). Tumor size ranged from 10 - 40 cm in the largest diameter(mean, 21 cm). Radiologic findings of thick, irregular wall or septum were notified in 14 tumors (70%), endocysticvegetation in 12 (60%), enhancing solid portion in 11 (55%), and calcification in two (10%). Of 18 mucinoustumors, 17 (94%) were multilocular. One serous tumor was unilocular and one was multilocular. Color Dopplerultrasonography of two mucinous tumors revealed blood flow signals in the wall, septum, solid portion orendocystic vegetation, and resistive indices were 0.5 and 0.4, respectively. CONCLUSION: When ovarian tumors arepresent - especially in young females and at a lower stage -, radiologic findings of a thick, irregular wall orseptum, endocystic vegetation, and a small enhanced solid component, for example, indicate the possibility ofovarian epithelial tumors of borderline malignancy.

CT Findings of Tumor and Mature Cystic Teratoma

PURPOSE: A tumor and mature ovarian cystic teratoma rarely coexist, but since it may affect treatment andprognosis, appropriate pre-surgical diagnosis is important. The purpose of this study was to evaluate thedifference in CT findings between a tumor coexisting with a mature ovarian cystic teratoma and a simple matureovarian cystic teratoma. MATERIALS AND METHODS: CT scans of seven cases of tumor coexisting with mature ovariancystic teratoma were reviewed. In each case, size, margin, nature, septation, solid portion, ascites, invasion,and metastasis were analysed. RESULTS: Coexistent tumors were histopathologically diagnosed as squamous cellcarcinoma in three patients, carcinoid in three, and fibrothecoma in one. In contrast with a simple matureteratoma, a tumor coexisting with a mature cystic teratoma developed in older patients and had a more solidportion, which showed contrast enhancement but did not show calcification or a fat component. Where a tumor andmature cystic teratoma coexisted, ascites and the invasion of adjacent structures were also common. CONCLUSION: If, in an older patient, CT scanning reveals an ovarian cystic tumor with a large solid portion but nocalcification or fat, coexistent tumor should be suspected.

Radiologic Findings of Endodermal Sinus Tumor of the Ovary

PURPOSE: To evaluate the radiologic features of endodermal sinus tumor of the ovary. MATERIALS AND METHODS:The radiologic findings of eight patients with pathologically-proven endodermal sinus tumor of the ovary wereretrospectively evaluated for bilaterality, size, margin, architecture, septa, local invasion, distant metastasis,ascites and lymphadenopathy ; serum alpha-FP was also evaluated. RESULTS: All endodermal sinus tumors were unilateralwith irregular septa and ascites ; the longest diameter was 7-18(mean, 12.6)cm. Four of eight tumors had smoothmargins and four, lobulated. Four were predominantly cystic in internal architecture, one was purely cystic, andthree were predominantly solid. There was local invasion or distant metastasis in three patients, andretroperitoneal lymphadenopathy in one ; in seven cases, alpha-FP level was more than 1.000ng/ml. CONCLUSION: Endodermal sinus tumors of the ovary appeared as nonspecific large complex abdominal masses and it was difficultto differentiate them from other malignant ovarian tumors. This tumor should be included in the differentialdiagnosis of a large complex abdominal mass in girls and young women, especially in patients with a predominantlycystic mass and markedly elevated serum alpha-FP.

Radiologic Findings of Granulosa Cell Tumor of the Ovary

PURPOSE: To evaluate the radiologic findings of granulosa cell tumor of the ovary. MATERIALS AND METHODS: Fourteen cases (fifteen tumors) of pathologically confirmed ovarian granulosa cell tumor were retrospectively analyzed on the basis of CT (n=10), MR imaging (n=4), and ultrasound (n=7) findings. The patients' mean age was 44.3 (range, 5-71) years. RESULTS: The mean diameter of the tumors was 12.1 (range, 5-26.5)cm. Thirteen cases were unilateral, and one was bilateral. Eleven tumors (ten cases) were mainly solid and eight of these had focal cystic components. Multilocular cysts accounted for three cases, and in two of these, mural nodules were present. One case was a unilocular cyst with no mural nodule. Ten cases were well demarcated. All the solid tumors were enhanced on postcontrast CT and MR imaging. Endometrial thickening was seen in five cases, ascites in six, and peritoneal implants or omental fat infiltration in five. One was associated with lymph node metastasis. All the postmenopausal patients had solid tumors, whereas 66.7% (4 of 6 cases) of young adults and children had cystic tumors. CONCLUSION: Granulosa cell tumors of the ovary were solid or cystic; the former were more common. There were no characteristic findings which permitted definitive differentiation from other ovarian tumors.

CT and MR Findings of Ovarian Fibroma

PURPOSE: To evaluate the charateristic CT and MR findings of primary ovarian fibromas. MATERIALS AND METHODS: We retrospectively reviewed 11 cases which had undergone precontrast and postcontrast scanning, and two in which cases T1-weighted (WI) and postcontrast T1WI and T2WI images had been done. All cases were pathologically confirmed after surgical resection. These masses were analysed on the basis of clinical symptom, age, size (longest diameter), laterality, margin, attenuation (unenhanced and enhanced), signal intensity (SI), calcification, and amount of the ascites. RESULTS: The patients' mean age was 46.6 (range, 22-81) years, and the longest diameter was 14.8 (range, 8-28)cm. All tumors were unilateral, and eight were located in the left ovary and five in the right ovary. In all cases, the tumor margin was well-defined; seven were lobulated, four were oval, one was round, and one was nodularly marginated. On CT scan, the masses showed mildl to moderate heterogenous enhancement with irregular lower density portions. The amount of the ascites was marked in three cases (23%) mild in two (15%), and minimal in three cases. Calcifications were seen in 3 of 11 CT cases (27%), and in one, this was extensive. On MR scans, signal intensity (SI) of the masses on T1WI was isoSI, relativetive to the uterine myometrium, and heterogeneously enhanced after infusion of contrast media. On T2WI, SI was slightly lower that of the uterine myometrium with internal high SI portions. CONCLUSION: The characteristic finding of ovarian fibroma is a unilateral, well-defined, oval or lobulated, solid mass with or without ascites and calcification. On CT scan, tumor has mild to moderate heterogeneous enhancement. On MR scan, SI of mass is isoSI on T1WI with heterogeneous enhancement, and low SI on T2WI due to fibrous component.

Ovarian Mucinous Cystadenocarcinoma in 17-year-old Girl: A Case Report

Malignant epithelial neoplasm usually occurs in postmenopausal women, with less than 10% of cases occurring in women under the age of 20. In patients below this age, the majority of ovarian tumors are of germ cell origin and malignant ovarian epithelial tumors are uncommon. We report US & CT imaging in a case of mucinous cystadenocarcinoma in a 17-year-old nullipara who complained of amenorrhea for 45 days and a palpable mass.

Radiologic Findings of Ovarian Granulosa Cell Tumor

PURPOSE: To determine, through an analysis of radiologic findings, whether the findings of granulosa cell tumors (GCTs) of the ovary are specific. MATERIALS AND METHODS: The radiologic findings (ultrasonography, computed tomography, and magnetic resonance imaging) of 16 pathologically proven ovarian GCTs in 15 patients were retrospectively analysed for the site of origin, staging, largest diameter, margin, solid and/or cystic components, degree of enhancement, and associated endometrial hyperplasia, ascites, and local and/or distant metastasis. RESULTS: Unilateral ovarian GCTs were found in 14 patients, and bilateral tumors in one. Of a totalof 16 tumors, 13 were of the adult type, and three were juvenile; their largest diameter ranged from 1 to 26 (mean, 15.6)cm. Eleven tumors were well-defined, two were cystic, and one small tumor was solid. Of 13 mixed tumors, three had hemorrhagic portions, and five had multilocular cystic portions. Metastases to the uterus, tubes, rectum, lymph nodes, or liver were found in six patients, and associated endometrial hyperplasia in two. CONCLUSION: Radiologically, ovarian GCTs showed well-defined or encapsulated soft tissue masses with some hemorrhagic, multiocular or focal cystic components, as well as associated endometrial thickening and local or distant metastasis. These and clinical findings may be useful in the diagnosis of ovarian GCTs.

CT Findings of Endometrioma: Differential Points from Other Benign Complex Cystic Adnexal Masses

PURPOSE: To evaluate whether CT scanning is useful in differentiating the between endometriomas and other benign complex cystic adnexal masses, and in determining the method of treatment for each mass lesion. MATERIALS AND METHODS: In 54 cases (47 patients), we retrospectively analysed the CT findings of 20 pathologically-proven twenty endometriomas (bilateral in four cases), eight hemorrhagic functional cysts, two tubal ectopic pregnancies, eight tubo-ovarian abscesses (bilateral in two cases), ten serous cystadenomas (bilateral in one case), and six mucinous cystadenomas. Internal attenuation, the hyperdense portion, adhesion, and cul-de-sac obliteration were evaluated by CT scanning. RESULTS: Fourteen endometriomas (70%) showed a hyperdense portion, and in only two of these (10%), was a focal nodular hyperdense portion seen on pre-contrast CT scan (10% sensitivity, 100% specificity). Partial or complete cul-de-sac obliteration was identified in 11 patients (75%), while hemorrhagic functional cysts showed a hyperdense portion in four cases (50%) and were accompanied by partial cul-de-sac obliteration in two (25%). Two unruptured tubal ectopic pregnancies showed CT findings of unilateral hyperdense cystic masses of more than 60 HU. In all cases, tubo-ovarian abscesses were accompanied by thickening of the uterosacral ligament and deviation of thickened mesosalpinx (anterior deviation in 87.5% of patients). Serous and mucinous cystadenomas showed CT findings of hypodense masses (less than 20 HU) without adhesion or cul-de-sac obliteration, and this was helpful in differentiating cystadenomas from other benign cystic adnexal masses, including endometriomas. CONCLUSION: The evaluation by CT scanning of benign complex cystic adnexal masses with respect to the hyperdense portion and the presence or absence of cul-de-sac obliteration was usful in differentiating endometriomas from other lesions, and might be helpful in determining the method of treatment for each mass lesion.

Radiologic Findings of Struma Ovarii

PURPOSE: Struma ovarii is ovarian tumor composed solely or predominantly of thyroid tissue or tumor in which hyperthyroidism results from ovarian thyroid tissue, and usually occurs in tandem with cystic teratoma. Ovarian cystic teratoma is radiologically easily diagnosed due to calcification or fat, for example, but the preoperative diagnosis of struma ovarii is often difficult due to rare characteristic features of thyroid tissue. Our purpose was to determine whether there were specific findings of struma ovarii which distinguished it from other ovarian tumors, and this involved analysis of its radiologic findings. MATERIALS AND METHODS: Using ultrasonography, computed tomography, and magnetic resonance imaging, preoperative radiologic findings of pathologically-proven struma ovarii in eleven patients were retrospectively evaluated for site, margin, nature (cystic, solid, mixed), contrast enhancement, septa, mural nodule, calcification, fat, and metastasis. These findings were compared with pathologic findings. RESULTS: All eleven tumors were unilateral, ten had smooth tumor margins, seven were mixed cystic and solid tumors (more than 70% of solid components in one tumor), and nine had regular septa. Three of four cystic masses (one unilocular, one bilocular and two multilocular cysts) had mural nodules. Calcifications were found in two tumors, and fat in one. Malignant change or metastasis was not found in any tumor. In one patient with hyperthyroidism due to struma ovarii, symptoms and signs of this subsided after removal of the tumor on salpingo-oophorectomy. CONCLUSION: Most cases of struma ovarii occurred unilaterally within ovarian teratomas in premenopausal women, and were mixed cystic and solid masses with smooth margins that are commonly enhanced on contrast enhanced scans. In one patient, hyperthyroidism was caused by struma ovarii. There were, however, no specific radiologic findings that were sufficiently typical to suggest the correct preoperative diagnosis of struma ovarii.

Whirling Sign: An Imaging Finding Indicating Ovarian Torsion

PURPOSE: To present a diagnostic sign on MRI and US in patients with ovarian torsion. MATERIALS AND METHODS: We present characteristic imaging findings in eight patients with surgically-proven ovarian torsion. MRI was performed in four patients, CT in six and US in all patients; the procedures including eight transabdominal US(TAS) and three transvaginal US(TVS). In each study, imaging findings were analyzed for the appearance of twisted pedicle and the presence of a "whirling sign". RESULTS: The pedicle which indicates ovarian torsion was detected on MRI in all 4 patients, on TAS in 4/7, on TVS in 3/3, and on CT in 4/6. A specific "whirling sign" was detected on MRI in 2/4 patients, on TAS in 2/4, and on TVS in all three. On CT a "whirling sign" was not detected. CONCLUSION: The "whirling sign" on both MRI & US is a characteristic finding of ovarian torsion; in a patient with adnexal mass and complaining of lower abdominal pain, the presence of this sign is very useful for the diagnosis of ovarian torsion.

Whirling Sign: An Imaging Finding Indicating Ovarian Torsion

PURPOSE: To present a diagnostic sign on MRI and US in patients with ovarian torsion. MATERIALS AND METHODS: We present characteristic imaging findings in eight patients with surgically-proven ovarian torsion. MRI was performed in four patients, CT in six and US in all patients; the procedures including eight transabdominal US(TAS) and three transvaginal US(TVS). In each study, imaging findings were analyzed for the appearance of twisted pedicle and the presence of a "whirling sign". RESULTS: The pedicle which indicates ovarian torsion was detected on MRI in all 4 patients, on TAS in 4/7, on TVS in 3/3, and on CT in 4/6. A specific "whirling sign" was detected on MRI in 2/4 patients, on TAS in 2/4, and on TVS in all three. On CT a "whirling sign" was not detected. CONCLUSION: The "whirling sign" on both MRI & US is a characteristic finding of ovarian torsion; in a patient with adnexal mass and complaining of lower abdominal pain, the presence of this sign is very useful for the diagnosis of ovarian torsion.

Differential Diagnosis of Malignant Ovarian Tumors on CT Findings

PURPOSE: To assess the value of CT for the differential diagnosis of malignant ovarian tumors. MATERIALS AND METHODS: We reviewed CT scans of 31 patients with surgically confirmed 46 malignant ovarian tumors. (29 epithelial tumors, 9 Krukenberg tumors, 6 germ cell tumors, and 2 sex cord-stromal tumors.) CT scans were evaluated for the mass (bilaterality, size, internal component, and margin), peritoneal spread pattern, ascites, invasion of adjacent organ, and lymphadenopathy. RESULT: Bilateral masses were seen in epithelial or Krukenberg tumor in 61.1%(11/18) and 80%(4/5) respectively. Epithelial tumors showed predominantly cystic mass(37.9%, 11/29), irregular margin(82.8%, 24/29) of mass, and accompanying peritoneal and omental spread (66.7%, 12/18), whileKrukenberg tumor showed predominantly solid mass(55.5%, 5/9), smooth margin of mass(100%, 5/5), and no peritoneal and omental spread. All cases with germ cell tumor or sex cord-stromal tumor showed unilateral mass. Relatively young aged, unilateral solid (66.7%, 4/6) tumors were germ cell tumor. Of these cases, septa within solid portionof mass were prominent in all dysgerminoma. (3/3) CONCLUSION: CT may be a valuable tool for the differential diagnosis of malignant ovarian tumors.

CT Findings of Ovarian Teratomas: Mature versus Immature

PURPOSE: To differentiate mature and immature ovarian teratomas, using CT findings. MATERIALS AND METHODS: The CT findings of ten mature ovarian teratomas (in one patient, bilateral) and ten which were immature were compared, using statistical analysis. images were evaluated for size, margins, architecture, contents (muralnodules, fat, calcification), septa, local invasion and distant metastasis. These findings were compared with pathologic findings. RESULTS: Of the ten mature tumors, nine were well defined and predominantly cystic ininternal architecture, and one was mixed. Mural nodules were found in six tumors, fat in all, distinct calcification in seven, and regular septa in three lesions. Of the ten immature tumors, eight had irregular margins, Seven were predominantly solid in internal architecture and irregularly enhanced, two were mixed, and one was mainly cystic. Fat was detected in five lesions, indistinct scattered calcification in six, irregular septa in three, and local invasion or distant metastasis in four patients. CONCLUSION: Compared with mature ovarianteratomas, those that are immature tend to show CT findings of marginal irregularity, solid mass with irregular enhancement, scattered indistinct calcifications, septal irregularity, local in vasion or distant metastasis. Our experience suggests that these findings may be helpful in differentiation of mature and immature ovarianteratomas.