Mature cystic teratomas of the ovary: CT and MR findings

MRI features of ovarian teratomas with somatic-type malignancy and mature cystic teratomas

PURPOSE

We evaluated the magnetic resonance imaging (MRI) features of ovarian teratomas with somatic-type malignancy (TSMs) and benign ovarian mature cystic teratomas (MCTs) to determine the diagnostic contribution of the MRI findings for differentiating these two teratomas.

METHODS

We compared the MRI findings between ovarian TSMs (n = 10) and MCTs (n = 193), and we conducted a receiver operating characteristic (ROC) analysis to determine the MRI findings' contribution to the differentiation of TSMs from MCTs.

RESULTS

The maximum diameters of whole lesion and the largest solid component in the TSMs were larger than those of the MCTs (p = 0.0001 and p < 0.0001, respectively). Fat tissue in solid components was seen in 73/116 (62.9%) MCTs but in none of the TSMs (p = 0.0001). Ring-like enhancement in solid components was seen in 60/116 (51.7%) MCTs and none of the TSMs (p = 0.0031). On dynamic contrast-enhanced MRI (DCE MRI), all of the solid components in the TSMs showed a high- or intermediate-risk time intensity curve (TIC), and those in 113 of the 116 (97.4%) MCTs showed a low-risk TIC (p < 0.0001). The area under the curve of the ROC analysis using the high-/intermediate-risk TIC on DCE MRI was the highest (0.99) for differentiating TSMs from MCTs: sensitivity 100%, specificity 97.4%, positive predictive value 75.0%, negative predictive value 100%, and accuracy, 97.6%.

CONCLUSION

Compared to ovarian MCTs, ovarian TSMs are larger and have larger solid components with high- or intermediate-risk TICs on DCE MRI. Ovarian MCTs frequently show small solid components with fat tissue, ring-like enhancement, and a low-risk TIC on DCE MRI.

Evaluation of calcification distribution by CT-based textural analysis for discrimination of immature teratoma

BACKGROUND

Mature and immature teratomas are differentiated based on tumor markers and calcification or fat distribution. However, no study has objectively quantified the differences in calcification and fat distributions between these tumors. This study aimed to evaluate the diagnostic potential of CT-based textural analysis in differentiating between mature and immature teratomas in patients aged < 20 years.

MATERIALS AND METHODS

Thirty-two patients with pathologically proven mature cystic (n = 28) and immature teratomas (n = 4) underwent transabdominal ultrasound and/or abdominal and pelvic CT before surgery. The diagnostic performance of CT for assessing imaging features, including subjective manual measurement and objective textural analysis of fat and calcification distributions in the tumors, was evaluated by two experienced readers. The histopathological results were used as the gold standard. The Mann-Whitney U test was used for statistical analysis.

RESULTS

We evaluated 32 patients (mean age, 14.5 years; age range, 6-19 years). The mean maximum diameter and number of calcifications of immature teratomas were significantly larger than those of mature cystic teratomas (p < 0.01). The mean number of fats of immature teratomas was significantly larger than that of mature cystic teratomas (p < 0.01); however, no significant difference in the maximum diameter of fats was observed. CT textural features for calcification distribution in the tumors showed that mature cystic teratomas had higher homogeneity and energy than immature teratomas. However, immature teratomas showed higher correlation, entropy, and dissimilarity than mature cystic teratomas among features derived from the gray-level co-occurrence matrix (GLCM) (p < 0.05). No significant differences were observed in the CT features of fats derived from GLCM.

CONCLUSION

Our results demonstrate that calcification distribution on CT is a potential diagnostic biomarker to discriminate mature from immature teratomas, thus enabling optimal therapeutic selection for patients aged < 20 years.

Fat-containing adnexal masses on MRI: solid tissue volume and fat distribution as a guide for O-RADS Score assignment

PURPOSE

To explore ways to improve O-RADS MRI scoring for fat-containing adnexal masses, by investigating methods for quantifying solid tissue volume and fat distribution and evaluating their associations with malignancy.

METHODS

This retrospective, single-center study included patients with fat-containing adnexal masses on MRI during 2008-2021. Two radiologists independently reviewed overall size (Sizeoverall), size of any solid tissue (Sizeanysolid), size of solid tissue that was not Rokitansky nodule (Sizenon-Rokitansky), and fat distribution. Wilcoxon test, Fisher-exact test, and ROC curve analysis were performed. Reference standard was pathology or follow-up > 24 months.

RESULTS

188 women (median age 35 years) with 163 benign and 25 malignant lesions were included. Sizeoverall (R1, 9.9 cm vs 5.9 cm; R2, 12.4 cm vs 6.0 cm), Sizeanysolid (R1, 5.1 cm vs 1.2 cm; R2, 3.2 cm vs 0.0 cm), Sizenon-Rokitansky (R1, 5.1 cm vs 0.0 cm; R2, 3.1 cm vs 0.0 cm), and fat distribution differed significantly between malignant and benign lesions (p < 0.01). Area under ROC curve was greatest using Sizenon-Rokitansky (R1, 0.83; R2, 0.86) vs Sizeoverall (R1, 0.78; R2, 0.81) or Sizeanysolid (R1, 0.79; R2, 0.81), though differences were non-significant (p = 0.48-0.93). Cutoffs for Sizenon-Rokitansky (R1, ≥ 1.2 cm; R2, ≥ 1.0 cm) yielded sensitivity and specificity of 0.72 and 0.93 (R1) and 0.76 and 0.95 (R2). Among immature teratomas, 85.7% displayed scattered fat.

CONCLUSION

Overall size, size of (any or non-Rokitansky-nodule) solid tissue, and fat distribution differed between benign and malignant fat-containing adnexal masses. Incorporating these would constitute simple and practical approaches to refining O-RADS MRI scoring.

Mucinous Epithelium in Endometrial Curetting Leading to Diagnostic Conundrum: A Case Report

Mucinous differentiation of the endometrium can occur in a spectrum of changes ranging from benign (metaplasia) to malignant (adenocarcinomas with mucinous differentiation). A rarer differential which is usually not considered is a teratoma. We present a case of a 55-yr-old woman with history of irregular perimenopausal bleeding. Endometrial curetting revealed proliferative mucinous epithelium on histology raising a possibility of low-grade epithelial mucinous malignancy. Hysterectomy was performed and histologic examination revealed a diagnosis of uterine mature teratoma. Mature cystic teratoma of the lower uterine segment is very rare and presence of just one element such as mucinous epithelium can lead to a misdiagnosis of carcinoma on biopsy or curetting.

Ovarian teratomas: clinical features, imaging findings and management

Ovarian teratomas are the most common type of germ cell tumors. There are three major subtypes of ovarian teratomas including mature, immature, and monodermal teratomas. Ultrasound, computed tomography and magnetic resonance imaging can demonstrate specific imaging findings for mature teratoma. Imaging features of immature and monodermal teratomas are less specific, but a combination of clinical features and imaging findings can help in the diagnosis. Imaging is also very helpful in guiding management. In this article, we review the epidemiology, histopathology, clinical presentation, imaging features and management of ovarian teratomas.

Pre-operative diagnosis of a primary uterine mature teratoma

OBJECTIVE

Mature cystic teratoma is a common benign ovarian tumor. But extragonadal teratomas are very rare. They mainly occur in the midline structure of the body. Uterine teratomas are extremely rare with only few reports. The diagnosis was mainly based on the operative findings. We report a case of uterine mature teratoma in a 37 year-old woman who was diagnosed before the operation. We also review the literature about this exceptional presentation.

CASE REPORT

We report a case of uterine teratoma that was initially diagnosed as a uterine tumor under ultrasound examination. But teratoma was highly suspected preoperatively by the abdominal CT scan. She underwent tumor excision via laparotomy. The operative finding and the histological examination confirms the diagnosis of primary uterine teratoma.

CONCLUSION

Preoperatively diagnosis of uterine teratoma was difficult. Although there are no gold standard to treat the uterine teratoma, the majority of the treatment choice is surgery. The prognosis of this unusual disease is relatively good in benign lesions.

CT and MRI characteristics of ovarian mature teratoma in patients with anti-N-methyl-D-aspartate receptor encephalitis

PURPOSE

The purpose of this study was to determine the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of ovarian mature teratoma in patients with anti-N-methyl-d-aspartate receptor encephalitis (NMDAR-E).

MATERIALS AND METHODS

A total of 125 women (mean age, 40.9±17.8 [SD] years; age range: 12-85 years) with 146 histopathologically or radiologically proven ovarian mature teratomas who underwent preoperative CT and MRI examinations were retrospectively included. Eight patients with 11 teratomas had NMDAR-E, whereas 117 patients with 135 teratomas did not have NMDAR-E. CT and MRI examinations were retrospectively reviewed and teratomas in patients with NMDAR-E were compared to those in patients without NMDAR-E. Comparisons were performed using Mann-Whitney U test or Fisher exact test.

RESULTS

In patients with NMDAR-E, maximum diameter of teratomas (26.1±9.3 [SD] mm), prevalence of teeth/calcification (36%) and rate of occupation by fat components (26%) were lower than those in patients without NMDAR-E (67.0±37.6 [SD] mm [P<0.01]; 75% [P<0.05]; and 65%[P<0.01], respectively). More than 75% of space was occupied by fat components in 76/135 teratomas (56%) in patients without NMDAR-E, whereas this was not observed in any teratoma in patients without NMDAR-E.

CONCLUSION

By comparison with teratomas in patients without NMDAR-E, teratomas in patients with NMDAR-E are smaller, have few teeth/calcification, and the amount of space occupied by fat components is smaller.

Mature ovarian cystic teratoma with disseminated nodular lesions in the pleural and peritoneal cavities: A case report

Mature ovarian cystic teratoma (MOCT) is the most common benign neoplasm of the ovary and has a wide spectrum of radiological presentations. Our aim was to present the radiological characteristics and pathologic findings of a patient with an atypical manifestation of this common disease. A 52-year-old Japanese woman was admitted to our hospital with a large cystic mass in the pelvis and an elevated squamous cell carcinoma antigen level. Computed tomography revealed disseminated cystic lesions in the intraperitoneal and intrathoracic spaces. The lesions contained fat and featured calcifications. Laparotomy revealed many white, spherical nodules in the peritoneal cavity. The results of pathologic examination led to a presumed diagnosis of a foreign body reaction to the contents of an MOCT that leaked into the peritoneal cavity. The patient has been followed up for 13 months and remains free of symptoms without additional treatment. We describe a rare presentation of MOCT, in which we initially strongly suspected an advanced malignancy based on the results of imaging. To make an accurate diagnosis, it is necessary to understand the rare findings associated with MOCT, as well as the common signs on different imaging modalities.

Imaging Patterns of Intratumoral Calcification in the Abdominopelvic Cavity

Intratumoral calcification is one of the most noticeable of radiologic findings. It facilitates detection and provides information important for correctly diagnosing tumors. In the abdominopelvic cavity, a wide variety of tumors have calcifications with various imaging features, though the majority of such calcifications are dystrophic in nature. In this article, we classify the imaging patterns of intratumoral calcification according to number, location, and morphology. Then, we describe commonly-encountered abdominopelvic tumors containing typical calcification patterns, focusing on their differentiable characteristics using the imaging patterns of intratumoral calcification.

Mature cystic teratoma of the ovary: a cutting edge overview on imaging features

Mature cystic teratoma (MCT) is the most common neoplasm of the ovary and includes at least two well- differentiated germ cell layers. Different combinations of mature tissue derivatives with varying arrangements in the tumour cause a wide spectrum of radiological presentation ranging from a purely cystic mass to a complex cystic mass with a considerable solid component. In different imaging modalities, each radiological feature reflects a specific pathologic equivalent that forms because of diverse compositions of histological components. Understanding uncommon findings as well as the classic signs with basic knowledge of pathological equivalents permits a more accurate diagnosis and guides adequate treatment. In this review, radiological features of MCT in different imaging modalities (US, CT, MR imaging) including specific signs and useful radiological artefacts with brief emphasis on pathological basics are discussed.

Teaching points

• Ovarian mature cystic teratomas (MCTs) have a wide spectrum of radiological presentation.

• Each radiological feature of MCT reflects a specific pathologic equivalent.

• Understanding radiological signs with basic knowledge of pathology can permit a more accurate diagnosis.

Management of Familial Ovarian Teratoma: The Need for Guidance

Ovarian teratomas in prepubertal females are uncommon, but familial ones are exceedingly rare. We report an ovarian teratoma in an 8-year-old girl, her mother, and her maternal grandmother. The risk of a metachronous tumor and subsequent complications (such as torsion) in the contralateral ovary remain unclear. There is no clear guidance on follow-up management of patient and family members in the literature. We have reviewed the literature and discuss the challenges for the pediatric surgeon arising from such cases.

A series of malignant ovarian cancers arising from within a mature cystic teratoma: a single institution experience

BACKGROUND

Mature cystic teratoma (MCT) is the most common germ cell tumor. It accounts for 10% to 20% of all ovarian masses. The likelihood of malignancy arising from within an MCT is low, and prognosis is poor.

METHODS

A single-institution retrospective chart review was completed of all cases of MCT from 2004 to 2012. Multiple variables were examined including procedure performed, residual disease after surgery, surgical stage, histologic type, site of primary disease, date of recurrence, whether or not adjuvant chemotherapy was given, and whether or not there was death secondary to disease.

RESULTS

During the study period, 1.2% of MCTs exhibited malignant transformation. The average age at presentation was 53.7 years. Mean follow-up time was 23 months. The most common presenting symptoms were bloating and abdominal pain. The average tumor size was 18 cm. Of note, 33% of cases were at least surgical stage IIIC at the time of presentation, whereas the remainder were stage IC or lower. Four (44.4%) of the 9 cases were identified as mucinous adenocarcinoma in addition to 1 case each of malignant melanoma, squamous cell carcinoma, and poorly differentiated adenocarcinoma. Only 1 patient experienced recurrence. One patient had a known MCT that was being managed expectantly and exhibited malignant transformation to a mucinous adenocarcinoma.

CONCLUSIONS

A large ovarian mass that is suspected to be a mature teratoma should be managed more aggressively in older patients. Our data suggest that although malignancy arising from mature teratomas is rare, it is more likely when patients are older than 40 years, the mass is greater than 18 cm, and there is any suspicion for a mucinous tumor. Like most ovarian tumors, these tumors most often present at later stages and, thus, can be difficult to treat. It is unclear what role chemotherapy or radiation plays in the management of these tumors.

Added Value of Assessing Adnexal Masses with Advanced MRI Techniques

This review will present the added value of perfusion and diffusion MR sequences to characterize adnexal masses. These two functional MR techniques are readily available in routine clinical practice. We will describe the acquisition parameters and a method of analysis to optimize their added value compared with conventional images. We will then propose a model of interpretation that combines the anatomical and morphological information from conventional MRI sequences with the functional information provided by perfusion and diffusion weighted sequences.

Imaging features of complex solid and multicystic ovarian lesions: proposed algorithm for differential diagnosis

Complex solid and multicystic ovarian lesions are broad-spectrum diseases, ranging from benign to malignant. This article describes the broad-spectrum and imaging features of complex solid and multicystic ovarian lesions and illustrates an algorithmic approach to such lesions, focusing on the ultrasonography and magnetic resonance imaging features that allow one to hone the differential diagnosis. Multimodality imaging workup plays an important role in the characterization and differential diagnosis of these diseases. Also, knowledge of the clinical setting and imaging features for the spectrum of complex solid and multicystic ovarian lesions can lead to appropriate management.

Ovarian tumors in children and adolescents: a series of 41 cases

OBJECTIVE

Pictorial review with a detailed semiological analysis of ovarian tumors in children and adolescents to provide a relevant diagnostic approach.

PATIENTS AND METHODS

Retrospective study (2001-2011) of 41 patients under the age of 15 who underwent surgery for an ovarian mass with a definite pathological diagnosis.

RESULTS

Sixty-two percent of the lesions were benign, 33% were malignant and 5% were borderline. Germ cell tumors were most frequent (77.5%), followed by sex cord stromal tumors (12.5%) and epithelial tumors (7.5%). Malignant tumors were more frequent in children between 0 and 2 years old. On imaging, calcifications and fat were specific for germ cell tumors; the presence of a mural nodule was predictive of a mature teratoma (P<0.001). Predictive factors for malignancy were clinical, including abdominal distension (P<0.01) or a palpable mass (P=0.05), biological, including increased hCG and/or AFP levels (P<0.001) and radiological, including tumors larger than 12 cm (P<0.05), tumoral hypervascularity (P<0.01) and voluminous ascites (P<0.01).

CONCLUSION

This semiological analysis confirms the role of imaging in diagnosing the etiology of ovarian lesions in children and adolescents and emphasizes the importance identifying tumoral hypervascularity, which, in addition to classic criteria, is highly predictive of malignancy.

Value of dynamic contrast-enhanced MRI for tissue characterization of ovarian teratomas: correlation with histopathology

AIM

To analyse the value of double contrast-enhanced (DCE) magnetic resonance imaging (MRI) in addition to conventional MRI to characterize ovarian teratomas subtypes with histological correlation.

MATERIALS AND METHODS

From January 2005 to December 2008, 38 women undergoing MRI and subsequent resection of ovarian teratomas were identified [40 mature cystic teratomas (MCT), two struma ovarii, three immature teratomas]. MRI images were analysed blindly by two radiologists according to morphological and vascular abnormalities. An experienced histopathologist reviewed all slides to determine the presence and histological composition of Rokitansky protuberances.

RESULTS

Thirty-one MCT (77%) had at least one small, regular Rokitansky protuberance presenting at an acute angle with the cyst wall. Ten out of 31 MCT did not display any enhancement on contrast-enhanced MRI related to sebaceous glands, adipose lobules, keratin, and pilosebaceous adnexa at histology. Three different time-intensity curve (TIC), types 1, 2, and 3, were related to presence of smooth muscular cells and fibrous, neuroglial, or thyroid tissue, respectively, found at histology of MCT. Type 3 TIC was also present in one struma ovarii and two immature teratomas.

CONCLUSION

TIC types are related to the specific content of the solid tissue of ovarian teratomas but cannot be used to differentiate benign and malignant ovarian teratomas.

Multimodality imaging of ovarian cystic lesions: Review with an imaging based algorithmic approach

Ovarian cystic masses include a spectrum of benign, borderline and high grade malignant neoplasms. Imaging plays a crucial role in characterization and pretreatment planning of incidentally detected or suspected adnexal masses, as diagnosis of ovarian malignancy at an early stage is correlated with a better prognosis. Knowledge of differential diagnosis, imaging features, management trends and an algorithmic approach of such lesions is important for optimal clinical management. This article illustrates a multi-modality approach in the diagnosis of a spectrum of ovarian cystic masses and also proposes an algorithmic approach for the diagnosis of these lesions.

Imaging of pediatric ovarian neoplasms

We review the clinical and imaging characteristics of the most common ovarian neoplasms in children and adolescents. Because of the widespread use of diagnostic imaging, incidental ovarian neoplasms might be encountered during the evaluation of abdominal pain, trauma or other indications and might pose a diagnostic dilemma. Conducting adequate imaging studies under these conditions is important, as management strategies differ according to the size and appearance of the lesion as well as the age of the patient. US dominates in gynecological imaging because of its excellent visualization, absence of ionizing radiation and sedation risks and comparatively low cost. For further examination of indeterminate lesions found using US, MRI is being used more progressively in this field, particularly for the evaluation of complex pelvic masses with the aim of distinguishing benign and malignant conditions and conditions requiring surgical intervention. CT is reserved primarily for tumor staging and follow-up and for emergency situations.

Multi-detector CT features of benign adnexal lesions

RATIONALE AND OBJECTIVES

The purpose of our study was to evaluate the multidetector computed tomography (MDCT) features of benign adnexal lesions.

METHODS AND MATERIALS

We report the MDCT features of 68 histologically proven benign adnexal lesions. Pathologic diagnoses were nonneoplastic adnexal cysts (n = 16), endometriomas (n = 12), serous or mucinous cystadenomas (n = 15), fibromas or fibrothecomas (n = 7), teratomas (n = 6), and a variety of benign adnexal lesions (n = 12). The CT protocol included scanning of the abdomen after the intravenous administration of iodinated contrast material (portal phase) using a detector collimation of 16 x 0.75 mm and a pitch of 1.2.

RESULTS

Ovarian cysts had a characteristic CT appearance of a cystic lesion, with smooth, thin wall, and occasionally a few septa. Serous and mucinous cystadenomas were detected as multilocular cystic tumors containing serous fluid or liquids of higher than water CT density, respectively. Dilated fallopian tube was seen as an oblong, tubular, fluid-filled structure. MDCT was accurate to characterize mature cystic teratomas. Endometriomas had a variable CT appearance, including a unilocular or multilocular cystic mass, and a homogeneous hyperdense mass lesion. Fibrous tissue had a 50 HU CT density in patients with fibromas or fibrothecomas.

CONCLUSION

MDCT may provide accurate diagnostic information about the benign nature of adnexal lesions.

Dynamic contrast-enhanced MR imaging of ovarian neoplasms: current status and future perspectives

MR imaging is useful for characterizing ovarian tumors. Dynamic contrast-enhanced MR imaging is a promising new technique useful for characterizing perfusion and angiogenesis of ovarian masses. This article describes the dynamic contrast-enhanced MR imaging technique examines the current and future applications of this technique in patients with ovarian tumors.

Mature and immature ovarian teratomas: CT, US and MR imaging characteristics

Ovarian teratomas (OTs) are the most common germ cell neoplasm. They include mature cystic teratomas, monodermal teratomas (neural tumors, struma ovarii, carcinoid tumors) and immature teratomas. Teratomas are the most common benign ovarian neoplasms in women less than 45 years old. OTs are usually characterized by ultrasound (US) and magnetic resonance (MR) whereas they are usually an incidental finding on CT. The purpose of this paper is to review the most common types of teratomas and to describe CT, US and MR imaging features of the various types of mature and immature OTs.

Imaging findings of complications and unusual manifestations of ovarian teratomas

Ovarian teratomas can be associated with various complications and demonstrate a wide spectrum of clinical and imaging features. The complications include torsion (16% of ovarian teratomas), rupture (1%-4%), malignant transformation (1%-2%), infection (1%), and autoimmune hemolytic anemia (<1%). These complications require different therapeutic strategies; therefore, timely and accurate diagnosis of these complications is important for optimal patient treatment. In cases of complicated ovarian teratomas, the clinical manifestations provide only limited information and often overlap with those of other diseases. Furthermore, ovarian teratomas may have unusual clinical and imaging manifestations, thereby leading to misdiagnosis. These unusual manifestations include immature teratomas, monodermal teratomas (struma ovarii), combination tumors and collision tumors containing teratomas, and mature cystic teratomas without demonstrable fat or with pure fatty components. To provide adequate treatment and prevent misdiagnosis, it is necessary to be familiar with the imaging findings of both the complications and the unusual manifestations of ovarian teratomas.

[Degeneration of dermoid cysts: a case study of malignant transformation]

Malignant transformation of ovarian dermoid cyst (mature cystic teratoma) is rare and most often established in postmenopausal women after surgery by sample anatomopathological analysis. We report the case of a 58-year-old woman showing abdominal pain associated with constipation episodes. The diagnosis of dermoid cyst was established upon ultrasonographic and tomodensitometric criteria. Its histopathological analysis confirmed the presence of a well differentiated epidermoid carcinoma. In line with the literature, our study highlights the importance of the age of the patient, the size of dermoid cyst and its growth rate as well as squamous cell carcinoma (SCC) antigen serum level. These date are collected in order to establish a correct diagnosis and provide an appropriate cure. When a cyst is discovered these data must pathological event, mostly observed in menopaused women. Certainty diagnosis is collected in order to establish a correct diagnosis and provide an appropriate cure.

A case of a mature cystic teratoma of the uterosacral ligament successfully treated by laparoscopic surgery

An asymptomatic tumor was found in the pelvic cavity of a 49-year-old woman during a routine examination. With a diagnosis of mature cystic teratoma of the right ovary, laparoscopic surgery was performed. The intraoperative finding showed the presence of a cystic tumor firmly attached to the uterosacral ligament in a position distant from the bilateral ovaries. Laparoscopic excision was performed, and the diagnosis of mature cystic teratoma of the uterosacral ligament was made histopathologically. This is the first report in the literature of successful laparoscopic treatment for a mature cystic teratoma of the uterosacral ligament.

Malignant transformation of an ovarian mature cystic teratoma: computed tomography findings

INTRODUCTION

The malignant transformation of an ovarian mature cystic teratoma is rare. We presented such a case of a 46-year-old woman with characteristic computed tomography (CT) findings.

CASE REPORT

The patient had suffered from fullness and tenderness of the lower abdomen for one year. A high serum CA-125 level was noted. Computed tomography images showed a left adnexal mass with fat, calcification and soft tissue components, and areas of invasion through the teratoma wall.

OUTCOME

The histologic diagnosis was compatible with a squamous cell carcinoma arising from a mature cystic teratoma of the ovary.

CT and MR imaging of ovarian tumors with emphasis on differential diagnosis

Ovarian tumors are classified on the basis of tumor origin as epithelial tumors (serous and mucinous tumors, endometrioid and clear cell carcinomas, Brenner tumor), germ cell tumors (mature and immature teratomas, dysgerminoma, endodermal sinus tumor, embryonal carcinoma), sex cord-stromal tumors (fibrothecoma; granulosa cell, sclerosing stromal, and Sertoli-Leydig cell tumors), and metastatic tumors. Epithelial tumors are primarily cystic and, when malignant, are associated with varying proportions of a solid component. Papillary projections are a distinctive feature of epithelial tumors. Profuse papillary projections are highly suggestive of borderline (low-malignant-potential) or malignant tumor. Ovarian teratomas demonstrate lipid material at computed tomography and magnetic resonance (MR) imaging. Malignant germ cell tumors manifest as a large, complex abdominal mass that contains both solid and cystic components. Tumor markers are helpful in diagnosis. The radiologic appearance of sex cord-stromal tumors varies from small solid masses to large multicystic masses. Granulosa cell tumors are usually large multicystic masses with solid components. Fibrothecoma, sclerosing stromal tumor, and Sertoli-Leydig cell tumors are usually solid masses. Fibromas have very low signal intensity on T2-weighted MR images. Certain radiologic findings predominate for each type of tumor. Knowledge of these key features of ovarian tumors provides the criteria for making a specific diagnosis or substantially narrowing the differential diagnosis.

Complex adnexal masses: detection and characterization with MR imaging--multivariate analysis

PURPOSE

To evaluate the accuracy of magnetic resonance (MR) imaging in the detection and characterization of complex adnexal masses, with particular reference to the findings predictive of malignancy, role of gadolinium-enhanced contrast material, and observer variability.

MATERIALS AND METHODS

Preoperative MR imaging of the pelvis was performed in 128 consecutive patients with clinically or ultrasonographically detected complex adnexal masses. Histopathologic examination demonstrated 187 masses, 96 of which were malignant. MR imaging studies were prospectively and independently reviewed by two radiologists, one of whom reevaluated the studies after a 6-month interval. The predictive value of MR imaging findings was determined with multivariate logistic regression analysis. The value of gadolinium enhancement was assessed by using receiver operating characteristic analysis. Inter- and intraobserver variabilities were assessed by using weighted K statistics.

RESULTS

Gadolinium-enhanced MR imaging depicted 176 (94%) of 187 adnexal masses, with an overall accuracy for the diagnosis of malignancy of 93%. The MR imaging findings that were most predictive of malignancy were necrosis in a solid lesion (odds ratio, 107) and vegetations in a cystic lesion (odds ratio, 40). Use of gadolinium-based contrast material contributed significantly to lesion characterization. Interobserver (K, 0.79-0.85) and intraobserver (K, 0.84-0.86) agreement were excellent.

CONCLUSION

Gadolinium-enhanced MR imaging is highly accurate in the detection and characterization of complex adnexal masses, with excellent inter- and intraobserver agreement.