Endometrioma
Updates to Article Attributes
Endometriomas,also known as a chocolate cysts or endeometriotic cysts, are a localised form of endometriosis and are usually within the ovary. They are readily diagnosed on ultrasound, with most demonstrating classical radiographic features.
Epidemiology
It affects women of reproductive age.
Pathology
Endometriomas contains dark degenerated blood products following repeated cyclical haemorrhage. The cysts may be up to 20 cm in size although they are usually smaller (2-5 cm).
Location
Typical locations include:
- ovaries: ~75%
- anterior/posterior cul-de-sac: ~70%
- posterior broad ligament: ~50%
- uterosacral ligaments: ~35%
- uterus: ~10 %
- colon: ~5%
Radiographic features
Plain film
Not usually helpful in diagnosis; ~10% of endometriomas can calcify.
Ultrasound
In the typical situation thereThe appearances of endometriomas can be quite variable.
The classical example is acousticof an unilocular cyst with acoustic enhancement with diffuse homogenous low-level internal echoeshomogeneous ground-glass echoes as a result of the haemorrhagic debris. This appearance occurs in 9550% of cases and is considered the classic finding on ultrasound examination. Features of multi-locularity and hyper-echoic7.
Less typical features include 7:
- multiple locules (~85% will have <5 locules)
-
hyperechoic wall foci
may be present. Anechoic - cystic-solid lesion (~15%) or purely solid lesion (1%)
-
anechoic cysts
may occur, but they are rare.(rare; 2%)
MRI
Signal characteristics vary according to the age of any complicating haemorrhage 6:
- T1: typically, lesions appear hyperintense while acute haemorrhage occasionally appears hypointense
-
T2
- typically hypointense owing to the presence of deoxyhaemoglobin and methaemoglobin
- old haemorrhage occasionally appears hyperintense
A shading sign 3 may be seen and is very suggestive of an endometrioma.
Treatment and prognosis
Although endometriomas are usually a benign entity, there is an ~1% rate of malignant transformation, seen mostly in women >40 years after several years of latency, with endometriomas larger than 9 cm 4-5. Malignant transformation is uncommon in masses <6 cm.
If not surgically excised, follow-up should be at least yearly 4. GnRH agonists may be used for medical management.
Differential diagnosis
General imaging differential considerations include:
- haemorrhagic ovarian cyst
- ovarian dermoid cyst: will show fat suppression on fat suppressed sequences on MRI
- cystic neoplasm
- tubo-ovarian abscess
-</ul><h4>Radiographic features</h4><h5>Plain film</h5><p>Not usually helpful in diagnosis; ~10% of endometriomas can calcify.</p><h5>Ultrasound</h5><p>In the typical situation there is acoustic enhancement with diffuse homogenous low-level internal echoes as a result of the haemorrhagic debris. This appearance occurs in 95% of cases and is considered the classic finding on ultrasound examination. Features of multi-locularity and hyper-echoic wall foci may be present. Anechoic cysts may occur, but they are rare.</p><h5>MRI</h5><p>Signal characteristics vary according to the age of any complicating haemorrhage <sup>6</sup>:</p><ul>- +</ul><h4>Radiographic features</h4><h5>Plain film</h5><p>Not usually helpful in diagnosis; ~10% of endometriomas can calcify.</p><h5>Ultrasound</h5><p>The appearances of endometriomas can be quite variable.</p><p>The classical example is of an unilocular cyst with acoustic enhancement with diffuse homogeneous ground-glass echoes as a result of the haemorrhagic debris. This appearance occurs in 50% of cases <sup>7</sup>.</p><p>Less typical features include <sup>7</sup>:</p><ul>
- +<li>multiple locules (~85% will have <5 locules)</li>
- +<li>hyperechoic wall foci</li>
- +<li>cystic-solid lesion (~15%) or purely solid lesion (1%)</li>
- +<li>anechoic cysts (rare; 2%)</li>
- +</ul><h5>MRI</h5><p>Signal characteristics vary according to the age of any complicating haemorrhage <sup>6</sup>:</p><ul>
References changed:
- 7. Van Holsbeke C, Van Calster B, Guerriero S et al. Endometriomas: Their Ultrasound Characteristics. Ultrasound Obstet Gynecol. 2010;35(6):730-40. <a href="https://doi.org/10.1002/uog.7668">doi:10.1002/uog.7668</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/20503240">Pubmed</a>
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