Diagnostic Ultrasound - Abdomen and Pelvis

Endometrioma
Diagnoses: Female Pelvis
TERMINOLOGY
• Endometriosis: Ectopic endometrial glands outside of
uterine cavity
• Endometrioma: Cystic collection of mixed blood products
IMAGING
• US
○ Diffuse low-level internal echoes in 95%
○ Increased through transmission
○ Homogeneous echotexture
○ Cyst wall with variable appearance
○ Endometrioma may look anechoic transabdominally
○ May see fluid-fluid level in cyst
• MR
○ T1WI: Homogeneous high signal
○ T2WI: Shading is distinguishing feature
• Cesarean section endometrioma
○ Abdominal wall mass
• Deep invasive endometriosis
KEY FACTS
○ Scarring, aggressive implants
• Decidualization during pregnancy can lead to solidappearing
adnexal masses
TOP DIFFERENTIAL DIAGNOSES
• Hemorrhagic cyst
○ Acute hemorrhage can mimic endometrioma
○ Fibrin strands
○ Resolves in 4-6 weeks
• Dermoid cyst (teratoma)
○ Hyperechoic, dirty shadowing, "tip of the iceberg" sign
○ Fat-fluid level
• Cystic neoplasm
○ Typically postmenopausal
CLINICAL ISSUES
• Infertility
• Cyclical or chronic pain
(Left) Endovaginal US
demonstrates small
homogeneously isoechoic
round endometrioma ſt
adjacent to normal ovarian
parenchyma containing
follicles st. Doppler US (not
shown) showed no internal
flow. (Right) Transverse
endovaginal US demonstrating
coexistent hemorrhagic cyst
ſt and endometrioma .
Note the homogenous
appearance of the echoes in
the endometrioma in
contradistinction to the fine
fibrin strands and mixed
echogenicity of the
hemorrhagic cyst.
(Left) Transverse
transabdominal US shows
bilateral cystic adnexal masses
with homogeneous low
level internal echoes.
Endometriomas are bilateral
in up to 50% of cases. (Right)
Color Doppler endovaginal US
demonstrates scattered
minimal areas of flow in the
mildly thickened wall of this
endometrioma which is
typical.
826