Sonography of benign cystic teratoma of the ovary: pitfalls in diagnosis

A case report of NMDAR encephalopathy - A neurologic condition that a gynecologist can cure

INTRODUCTION AND IMPORTANCE

Anti-NMDA receptor encephalitis is a rare autoimmune cause of acute psychosis in young women, often associated with ovarian teratomas. Surgical removal of the teratoma is a critical component of treatment.

CASE PRESENTATION

A previously healthy woman was brought to the emergency department with acute psychosis, characterized by alternating episodes of catatonia and mania, regressive speech, and inappropriate behaviors such as disrobing. Despite treatment with antipsychotic medications at a psychiatric facility, her symptoms did not improve, prompting transfer to our institution. Neurological examination was non-focal, and laboratory results were unremarkable. Cerebrospinal fluid analysis showed no signs of infection, but anti-NMDA antibodies were detected. Gynecology was consulted, and a pelvic ultrasound was initially negative. However, pelvic MRI revealed an area of macroscopic fat in the left ovary, suggesting a teratoma. The patient underwent laparoscopic left salpingo-oophorectomy. Gross examination of the ovary appeared normal, but histological analysis confirmed the presence of a benign teratoma with ganglion cells and chronic inflammation. The diagnosis of anti-NMDA receptor encephalitis was confirmed. Postoperatively, the patient's mental status improved significantly, and she was discharged home.

CLINICAL DISCUSSION

This case illustrates the clinical, radiologic, and histopathologic features of the disease and underscores the importance of MRI in detecting ovarian teratomas when pelvic ultrasound is inconclusive.

CONCLUSION

Timely gynecologic intervention can be curative in these patients.

Mature Cystic Teratoma: An Integrated Review

Ovarian dermoid cysts, also called mature cystic teratomas (MCTs), account for 69% of ovarian germ cell tumors in young women. The tumors are formed by tissues derived from three germ layers, and sebaceous materials are most commonly seen. The origin of MCTs is widely considered to be the germ cell origin, which completes meiosis I. The clinical symptoms vary widely, but 20% of tumors could be asymptomatic. The diagnosis of MCTs is usually made without difficulty by ultrasound and confirmed by histopathology post-operatively. The imaging findings have a high diagnostic value. The typical characteristics present in the sonographic images, including a dermoid plug or Rokitansky nodule, are considered strong evidence for a teratoma. Although the malignant transformation of MCTs is rare, it can occur in some cases, especially in women of advanced age. The treatment of MCTs depends on the risk of malignancy, the age of the patient, and the patient's fertility reserve requirement. In this article, we review the epidemiology, clinical symptoms, diagnosis criteria, cellular origin, and treatment of mature cystic teratomas.

Predictive value and prevalence of refractive edge shadow in diagnosis of ovarian dermoids

OBJECTIVE

To evaluate the diagnostic performance of refractive edge shadow in evaluation of ovarian dermoids compared to other benign adnexal masses.

METHODS

Ultrasound images of 139 patients with 154 dermoids, endometriomas, and hemorrhagic cysts were retrospectively reviewed by 3 radiologists blinded to final diagnosis. Ultrasound and clinical features were compared to pathology or follow-up ultrasound results as reference standard. Inter-reader agreements with free-marginal kappa and diagnostic performance were evaluated. The former was compared using Fisher's exact test or Mann-Whitney test with p < 0.05 to determine statistical significance.

RESULTS

The study sample consisted of 154 lesions: 50 dermoids, 50 endometriomas, and 54 hemorrhagic cysts. Refractive edge shadow, homogeneous echogenic appearance, tip of the iceberg sign, mural echogenic nodule, echogenic shadowing focus, and dot-dash sign all were statistically significant across all readers for the diagnosis of dermoid. Prevalence of each feature in dermoids compared to other entities were as follows: refractive edge shadow (70% vs 8%; p < 0.001), homogeneously echogenic appearance (34% vs 2%; p < 0.001), tip of the iceberg sign (16% vs 1%; p < 0.001), mural echogenic nodule (38% vs 2%; p < 0.001), echogenic shadowing focus (13% vs 1%; p < 0.001), and dot-dash sign (44% vs 1%; p < 0.001). Refractive edge shadow had the highest sensitivity, negative predictive value, and accuracy among all ultrasound features associated with dermoids (70%, 86%, and 85%, respectively).

CONCLUSION

Refractive edge shadow is a promising ultrasound feature for diagnosis of dermoids, with the highest diagnostic accuracy and prevalence compared to other previously described features associated with dermoids.

Acute post-traumatic dermoid peritonitis: A rare entity

Rupture of ovarian dermoid-cyst is rare case. We report the case of a woman admitted for acute post-traumatic abdominal pain due to ruptured ovarian cyst. The patient was operated and we found a very abundant peritoneal effusion with left ovarian cyst which was broken. we performed a left adnexectomy.

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.

Mature Ovarian Cystic Teratoma Mimicking a Bladder Diverticulum in a 16-year-old Female

A 16-year-old female was incidentally found to have an abnormal pelvic ultrasound while undergoing evaluation for mild scoliosis. A large, thick-walled, lobular, fluid-filled structure was found at midline in the pelvis that initially resembled bladder diverticula due to its anatomical position and sonographic appearance. Voiding cystourethrogram and computed tomography later revealed a large cystic mass originating from the right ovary. This report outlines a case of a mature cystic teratoma convincingly mimicking bladder anomaly on sonography.

Mature cystic ovarian teratoma without intracystic fat: Case report with the "fat within the wall" sign

Mature cystic teratoma is the most common ovarian neoplasm among young females. Diagnosed through radiological imaging as it exhibits typical radiological features; typically, fat. However, complete cystic teratoma without visible fat is a very rare and challenging diagnosis. It is difficult to distinguish it from malignant neoplasm, due to the presence of enhancing components, for example, Rokitansky nodule and the presence of diffusion restriction from keratinized products. We present a case of an incidental mature cystic teratoma without visible intracystic fat, where the correct diagnosis based on imaging was failed. Mature cystic teratoma was then confirmed upon histologic examination.

Ovarian neoplasms of childhood

Ovarian neoplasms are rare in children. Although usually asymptomatic, they sometimes present with abdominal pain, abdominal distension or palpable mass. The distribution of neoplasms in the pediatric population is different from in adults; benign mature cystic teratoma is the most common ovarian tumor in children. Radiologists should be familiar with the variable sonographic, CT and MRI findings of ovarian neoplasms. Although the less frequently encountered ovarian malignancies cannot be reliably distinguished by imaging alone, it does play an important role in workup. This review discusses the imaging and relevant clinical manifestations of the more commonly encountered pediatric ovarian neoplasms.

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.

Diagnosis of Cystic Teratoma Facilitated by Point-of-Care Ultrasonography

Abdominal pain and constipation are common chief complaints in the pediatric emergency department. We present a case of a child with pain, abdominal distention, and constipation ultimately diagnosed with an ovarian teratoma and the role of point-of-care ultrasonography in the evaluation.

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.

Gastric teratoma in an infant: a rare case report and discussion

Gastric teratoma is a rare tumor, accounting for less than 1 % of all teratomas in infants & children. To date, only about 102 cases have been reported in the literature. A 10 month old infant was brought with a history of upper abdominal mass which was otherwise asymptomatic. On evaluation it was diagnosed as gastric teratoma. On laparotomy the mass was found to be originating from lesser curvature of stomach. Mass was excised and histopathologically it was a mature cystic teratoma. No recurrence after 18 months of follow-up.

Massive ovarian cystic teratomas diagnosed at a rural Nepal camp

This case report presents the findings of significantly large sized (> 8 cm) symptomatic unilateral cystic teratomas in two perimenopausal patients in remote Nepal.

Ovarian dermoid cysts consist of cystic, solid and fat tissue. Traditionally, cells differentiate along the various germ lines, essentially recapitulating various body tissues. The characteristic sonographic features include a dermoid plug, dermoid mesh, a fat‐fluid level and the “tip of the iceberg” sign.

The presence of two or more of these typical features confidently supports an ultrasound‐based diagnosis of ovarian dermoid cyst.

The presence of intratumoral hair, teeth, fat, and skin tissue revealed at surgery confirmed the initial ultrasound based diagnosis.

Ultrasound of ovarian dermoids - sonographic findings of a dermoid cyst in a 41-year-old woman with an elevated serum hCG

Ovarian dermoid cysts are made up of solid, cystic and fat tissue. These components give rise to characteristic sonographic features such as a fat-fluid level, dermoid mesh and tip of the iceberg sign. The presence of two or more of these typical features can be used to confidently diagnose a dermoid cyst on ultrasound. This 41-year-old woman with a known cystic lesion on her right ovary which, on ultrasound, demonstrated two of these features, had the diagnosis of a dermoid cyst later confirmed on histopathology. She concurrently had an elevated serum human chorionic gonadotrophin (hCG), an unusual, but not unknown, finding in the presence of a dermoid cyst. The hCG resolved after removal of the ovarian cyst.

Expectant management of ultrasonically diagnosed ovarian dermoid cysts: is it possible to predict outcome?

OBJECTIVE

The aim of this study was to assess the natural history of ultrasonically diagnosed ovarian dermoid cysts in a large group of women who were managed expectantly, and to assess the factors that were associated with failure of expectant management.

METHODS

Our database was searched for dermoid cysts diagnosed on ultrasonography by a single expert operator between 2001 and 2007 in this retrospective study. In women who opted for expectant management, demographic data including age, gravidity and parity were recorded. Indications for scan, site of cysts, dimensions and the outcomes of expectant management were also recorded.

RESULTS

Two hundred and eighty-nine women were diagnosed with a total of 323 dermoid cysts by a single expert ultrasound operator. 93/289 (32.2%; 95% CI, 26.8-37.6%) women with 105/323 (32.5%; 95% CI, 27.4-37.6%) ovarian dermoid cysts were managed expectantly for longer than 3 months. The mean age at diagnosis was 33.8 (range, 13-79) years and the median duration of follow up was 12.6 (interquartile range, 7.6-29.3) months. The mean growth rate of dermoid cysts during follow up was 1.67 mm/year. There were no demographic or morphological features that could be used to predict the growth rate of dermoid cysts. After a period of expectant management, 24/93 (25.8%; 95% CI, 16.9-34.7%) women had surgical intervention. The risk of surgical intervention was significantly increased in younger women, those of parity > or = 2 and in women with bilateral cysts or larger-diameter cysts, and reduced in women with a past history of ovarian cyst.

CONCLUSIONS

The success rate of expectant management of dermoid cysts is high and this approach should be considered as a viable alternative to surgical management.

Management of asymptomatic ovarian and other adnexal cysts imaged at US: Society of Radiologists in Ultrasound Consensus Conference Statement

The Society of Radiologists in Ultrasound convened a panel of specialists from gynecology, radiology, and pathology to arrive at a consensus regarding the management of ovarian and other adnexal cysts imaged sonographically in asymptomatic women. The panel met in Chicago, Ill, on October 27-28, 2009, and drafted this consensus statement. The recommendations in this statement are based on analysis of current literature and common practice strategies, and are thought to represent a reasonable approach to asymptomatic ovarian and other adnexal cysts imaged at ultrasonography.

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.

[Ovarian dermoid cyst complicated by chemical peritonitis. Case report]

Dermoid cyst is the most frequent benign ovarian tumor. Its spontaneous or more frequently iatrogenic intraperitoneal rupture may lead to a chemical peritonitis. This is a rare complication but with a potentially dangerous issue. We report a case of a patient who developed chemical peritonitis after laparoscopic management of ovarian dermoid cysts. Three further interventions, associated with systemic anti-inflammatory treatment, were necessary to resolve symptoms completely. On the basis of this case, we aim to re-access the characteristics of dermoid cysts and highlight in particular the potential complication of chemical peritonitis and the following attitude to avoid this.

The ability of ultrasound to detect gynaecological neoplasms and their ultrasound morphological features

To determine first, the accuracy of a gynaecological ultrasound service in the detection of four clinically significant pathologies, namely, uterine body malignancy, ovarian malignancy, ovarian dermoid cysts and other benign ovarian pathologies and second, to review the ultrasound imaging appearances of ovarian masses with histopathological correlation. Retrospective data collection from consecutive weekly multidisciplinary team meetings over a 12-month period. All patients had undergone ultrasound examination before surgery. Data included patient demographics, menopausal status, indications for ultrasound, type of practitioner carrying out the scan, operative findings and final histopathological diagnosis. Ultrasound imaging appearances were correlated to histology. Of the 47 cases of uterine malignancy, 45 had endometrial carcinoma. All had either a thickened or poorly seen or not seen endometrium. Twenty-four per cent of these women were premenopausal. Forty-seven of the 48 cases of ovarian malignancy had abnormal ultrasound findings. In six of these, the findings were of a purely cystic lesion. There were 62 cases of benign ovarian pathology (excluding dermoid cyst), all of which had an abnormal ultrasound; 16 of these had possible ultrasound features of malignancy. All 30 cases of ovarian dermoid cyst had an abnormal ultrasound with a specific diagnosis being made in 27. This study shows that ultrasound is accurate in the detection of both endometrial and ovarian disease. The endometrium that is not seen or is poorly seen is an indication for endometrial biopsy in women with postmenopausal bleeding. There is considerable overlap in the ultrasound appearances of benign and malignant ovarian lesions. Ultrasound is a good method for the accurate and specific diagnosis of an ovarian dermoid cyst.

Numerous intracystic floating balls as a sonographic feature of benign cystic teratoma: report of 5 cases

OBJECTIVE

The purpose of this series was to describe the unusual but unique sonographic pattern of mature cystic teratoma.

METHODS

Five patients of reproductive age with clinical manifestations of a pelvic mass were evaluated with sonography for treatment planning.

RESULTS

All 5 cases showed the similar sonographic pattern of a large cystic tumor filled with multiple echogenic spherical structures floating in the cystic background. Of the 5 patients, 3 had rather large balls varying in size between 1 and 4 cm in the same tumor masses, whereas the other 2 had numerous smaller balls of about 0.5 cm in diameter. The numerous crowded very small echogenic balls in the last 2 cases mimicked solid nodules representing malignancy. However, there was no vascularization in the balls, which suggested a benign nature. The postoperative pathologic diagnosis was mature cystic teratoma without any malignant component in all cases.

CONCLUSIONS

The sonographic feature of intracystic floating echogenic balls is probably pathognomonic for mature teratoma and is easily detected in most cases. Color Doppler sonography is helpful in differentiating these benign nodules (small balls) from malignant tumors.

Ovarian teratoma diagnosis and management: case presentations

BACKGROUND

Ovarian teratomas (OTs) may be of mature or immature morphologies. Mature cystic teratomas (MCTs), often referred to as dermoid cysts, are the most common germ cell tumours of the ovary in women of reproductive age. OTs are usually asymptomatic until they reach considerable size. Frequently, ultrasonography is diagnostic. Women requiring surgery for OTs should be appropriately counselled about the risks and benefits of laparoscopic and open approaches.

CASE PRESENTATIONS

Case I: An 18-year-old woman presented with hirsutism and irregular menses, both of which reversed after bilateral MCT removal by laparoscopy. Case II: A 47-year-old multigravid woman presented with a large unilateral OT, with a focus of malignancy. Case III: A 19-year-old woman presented with a large unilateral OT associated with gliomatosis peritonei.

CONCLUSION

Experienced laparoscopic surgeons should consider laparoscopy as an alternative to laparotomy in management of OT in selected cases. Women younger than 15 years of age or older than 45 years of age who have large, solid teratomas on ultrasound or positive markers for germ cell tumours are at risk for malignant variants, and for these women laparotomy is the preferred approach.

Mature mediastinal teratoma: sonographic imaging patterns and pathologic correlation

OBJECTIVE

To characterize the sonographic patterns of teratomas located within the mediastinum and to correlate them with pathologic findings, because there have been few reports concerning the application of sonography in the diagnosis of mediastinal teratoma.

METHODS

Over a 9-year period, we carried out an image analysis of the sonographic findings of 28 mediastinal teratomas whose diagnoses were proved surgically.

RESULTS

Sonography showed that 18 patients had a complex mass of heterogeneous echogenicity, including regional bright echoes (n = 12), acoustic shadows (n = 8), hyperechoic lines and dots (n = 7), soft tissue septa (n = 9), dermoid plugs (n = 6), and hypoechoic areas (n = 11). This type of mediastinal teratoma revealed, in pathologic findings, varying combinations of fat, sebaceous and mucinous materials, hair, mineralized elements, and multiple compartments. Eight patients had a homogeneous hyperechoic mass, and the 2 remaining patients had floating spherules within a cystic mass. Pathologically, the homogeneous mass mainly contained hair and sebaceous material. The floating spherules were also composed of sebaceous tissue and were above the fluid of the cyst.

CONCLUSIONS

On the basis of the evaluation of the sonographic and pathologic findings, we described 3 major patterns of mediastinal teratoma: a complex mass of heterogeneous echogenicity, homogeneous high echogenicity within a solid mass, and floating spherules within a cystic mass. Thus, sonography can improve the diagnosis of mediastinal teratoma. However, additional prospective studies are needed to test the sensitivity and specificity of these sonographic patterns in the diagnosis of mediastinal teratoma.

Ovarian teratomas: tumor types and imaging characteristics

Ovarian teratomas include mature cystic teratomas (dermoid cysts), immature teratomas, and monodermal teratomas (eg, struma ovarii, carcinoid tumors, neural tumors). Most mature cystic teratomas can be diagnosed at ultrasonography (US) but may have a variety of appearances, characterized by echogenic sebaceous material and calcification. At computed tomography (CT), fat attenuation within a cyst is diagnostic. At magnetic resonance (MR) imaging, the sebaceous component is specifically identified with fat-saturation techniques. The US appearances of immature teratoma are nonspecific, although the tumors are typically heterogeneous, partially solid lesions, usually with scattered calcifications. At CT and MR imaging, immature teratomas characteristically have a large, irregular solid component containing coarse calcifications. Small foci of fat help identify these tumors. The US features of struma ovarii are also nonspecific, but a heterogeneous, predominantly solid mass may be seen. On T1- and T2-weighted images, the cystic spaces demonstrate both high and low signal intensity. Familiarity with the US, CT, and MR imaging features of ovarian teratomas can aid in differentiation and diagnosis.

The characterization of common ovarian cysts in premenopausal women

OBJECTIVES

The evaluation of the predictive value of transvaginal ultrasound in the assessment of benign adnexal pathology in premenopausal women, based on the recognition of characteristic morphologic patterns particular to endometriotic and dermoid ovarian cysts.

METHODS

This was a prospective study. All premenopausal women undergoing surgery for a suspected ovarian cyst underwent a transvaginal ultrasound examination in the week prior to surgery. Between June 1997 and January 2000, 132 women underwent surgery for a suspected ovarian endometrioma or dermoid cyst. The endpoints were either the direct visualization of the cyst wall and contents at surgery, or the histologic evaluation of removed tissues.

RESULTS

Of 83 suspected endometriomas (11 bilateral), 80 were confirmed at surgery and of 68 suspected benign cystic teratomas (eight bilateral), 66 were confirmed by histology. The positive predictive value of transvaginal ultrasonography for the diagnosis of endometrioma and dermoid cysts was 96.4% and 97.1%, respectively. The false positive rates were 3.8% and 3.0%, respectively. There were no malignancies in either group.

CONCLUSIONS

Based on the recognition of characteristic ultrasound patterns alone, the positive predictive value of transvaginal ultrasonography for the diagnosis of these common, benign cysts in premenopausal women is very high and can be used reliably to select women for appropriate surgery.

Value of fat-suppression gradient-echo MR imaging in the diagnosis of ovarian cystic teratomas

Gradient-echo MR imaging (MRI) was evaluated for the diagnosis of ovarian mature cystic teratomas (MCTs). The FLASH technique was applied to T1-weighted images with and without fat suppression in 18 surgical operated patients with 19 MCTs, and findings were compared to those of conventional spin-echo (SE) T1-weighted-SE. Seventeen out of 19 MCTs were correctly diagnosed using FLASH and SE T1-weighted MR images with and without fat saturation. This study suggests that gradient-echo MRI can replace conventional SE T1-weighted MRI for the diagnosis of ovarian MCTs.

Sonographic features of incidentally detected, small, nonpalpable ovarian dermoids

PURPOSE

We describe the transvaginal sonographic features of incidentally detected, small, nonpalpable ovarian dermoid cysts.

METHODS

A total of 38 small (less than 3 cm in diameter), nonpalpable, incidentally discovered ovarian dermoids in 35 women were retrospectively reviewed; 3 patients had small bilateral lesions, and 7 had a small ovarian dermoid detected during preoperative evaluation of a symptomatic, large, contralateral lesion.

RESULTS

Transvaginal sonography permitted identification of all 38 dermoids, whereas abdominal sonography detected only 22 of the lesions. Three main structural patterns were observed with transvaginal sonography: (1) 20 of 38 lesions had a solid, hyperechoic appearance, either homogeneous (11) or heterogeneous (9); (2) a fluid-filled area with a hyperechoic focus in its wall was seen in 10 cases; and (3) a mixed pattern, with solid and liquid areas, was seen in 8 cases. Calcifications were appreciated in 7 lesions. Acoustic shadowing was noted in 30 cases, either as a shadow posterior to the hyperechoic portion of the mass or as an edge shadow lateral to the lesion. Doppler studies were obtained for 20 lesions but proved inconclusive: 4 mixed-pattern dermoids had a few internal signals with a low resistance pattern; in the remaining cases, there were signals at the periphery of the cysts, but it could not be determined whether these were from vessels within the lesions or from vessels in the surrounding ovarian parenchyma. Surgery confirmed benign cystic dermoids in all 38 cases.

CONCLUSIONS

Sonographically, small ovarian dermoids have a variety of textural patterns quite similar to those encountered in large, symptomatic lesions. The increased resolution capabilities provided by transvaginal sonography allow incidental detection of previously unsuspected dermoids and permit identification of their nature.