Ovarian germ cell tumor ultrasound: Difference between revisions
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MR evaluation usually tends to be reserved for difficult cases, but is exquisitely sensitive to fat components. Both fat suppression techniques and chemical shift artefact can be used to confirm the presence of fat. | MR evaluation usually tends to be reserved for difficult cases, but is exquisitely sensitive to fat components. Both fat suppression techniques and chemical shift artefact can be used to confirm the presence of fat. | ||
Enhancement is also able to identify solid invasive components, and as such can be used to accurately locally stage malignant variants.==References== | Enhancement is also able to identify solid invasive components, and as such can be used to accurately locally stage malignant variants. | ||
Immature ovarian teratoma | |||
The imaging appearance is typically of a large, heterogeneous mass with a prominent solid component. However, the spectrum of appearances ranges from a predominatly cystic to a predominantly solid mass. Immature teratomas tend to be larger than mature cystic teratomas at initial presentation. | |||
Extension through the tumour capsule may be present. | |||
Immature teratoma may metastasise to peritoneum, liver or lung. Metastasis to brain has also been reported 7. | |||
Pelvic ultrasound | |||
Ultrasound appearance can be as a heterogeneous adnexal mass although is non-specific. Calcifications may be present. | |||
CT and MRI | |||
The presence of a prominent solid component containing calcifications and small foci of fat is suggestive. Cystic components may contain serous, mucinous, or fatty sebaceous material. Haemorrhage may be present. | |||
==References== | |||
{{reflist|2}} | {{reflist|2}} | ||
[[Category:Disease]] | [[Category:Disease]] | ||
Revision as of 21:15, 11 November 2015
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Ovarian germ cell tumor Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Ovarian germ cell tumor ultrasound On the Web |
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American Roentgen Ray Society Images of Ovarian germ cell tumor ultrasound |
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Risk calculators and risk factors for Ovarian germ cell tumor ultrasound |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Monalisa Dmello, M.B,B.S., M.D. [2]
Ultrasound dysgerminomas May be seen as a septated ovarian mass with varying echotexture. Colour Doppler interrogation may show prominent flow signal within the fibrovascular septa 2.
CT
Calcification may be present in a speckled pattern. Characteristic imaging findings include multilobulated solid masses with prominent fibrovascular septa. Post contrast imaging can often show enhancement of the septae.
MRI
Tumours are often seen divided into lobules by septa.
Reported signal characteristics include:
T2: the septae are often hypointense or isointense 3 T1 C+ (Gd): the septae often show marked enhancement 3
Conventional radiography
Mature (cystic) ovarian teratomaMay show calcific and tooth components with the pelvis.
Pelvic ultrasound
Ultrasound is the preferred imaging modality. Typically an ovarian dermoid is seen as a cystic adnexal mass with some mural components. Most lesions are unilocular.
The spectrum of sonographic features includes:
diffusely or partially echogenic mass with posterior sound attenuation owing to sebaceous material and hair within the cyst cavity echogenic interface at the edge of mass that obscures deep structures: the tip of the iceberg sign
mural hyperechoic Rokitansky nodule: dermoid plug echogenic, shadowing calcific or dental (tooth) components presence of fluid-fluid levels 5 multiple thin, echogenic bands caused by hair in the cyst cavity: the dot-dash pattern colour Doppler: no internal vascularity internal vascularity requires further workup to exclude a malignant lesion
CT
CT has high sensitivity in the diagnosis of cystic teratomas 6 though it is not routinely recommended for this purpose owing to its ionising radiation.
Typically CT images demonstrate fat (areas with very low Hounsfield values), fat-fluid level, calcification (sometimes dentiform), Rokitansky protuberance, and tufts of hair. The presence of most of the above tissues is diagnostic of ovarian cystic teratomas in 98% of cases 5. Whenever the size exceeds 10 cm or soft tissue plugs and cauliflower appearance with irregular borders are seen, malignant transformation should be suspected 5.
When ruptured, the characteristic hypoattenuating fatty fluid can be found as antidependent pockets, typically below the right hemidiaphragm, a pathognomonic finding 2. The escaped cyst content also leads to a chemical peritonitis and the mesentery may be stranded and the peritoneum thickened, which may mimicperitoneal carcinomatosis 2.
Pelvic MRI
MR evaluation usually tends to be reserved for difficult cases, but is exquisitely sensitive to fat components. Both fat suppression techniques and chemical shift artefact can be used to confirm the presence of fat.
Enhancement is also able to identify solid invasive components, and as such can be used to accurately locally stage malignant variants.
Immature ovarian teratoma
The imaging appearance is typically of a large, heterogeneous mass with a prominent solid component. However, the spectrum of appearances ranges from a predominatly cystic to a predominantly solid mass. Immature teratomas tend to be larger than mature cystic teratomas at initial presentation.
Extension through the tumour capsule may be present.
Immature teratoma may metastasise to peritoneum, liver or lung. Metastasis to brain has also been reported 7.
Pelvic ultrasound
Ultrasound appearance can be as a heterogeneous adnexal mass although is non-specific. Calcifications may be present.
CT and MRI
The presence of a prominent solid component containing calcifications and small foci of fat is suggestive. Cystic components may contain serous, mucinous, or fatty sebaceous material. Haemorrhage may be present.