Terminology
•
Uterine endometriosis
•
Endometriosis interna
Definitions
•
Heterotopic endometrial tissue within myometrium with adjacent smooth muscle
hyperplasia
Best diagnostic clue
·
Uterine enlargement with poor definition of endometrial-myometrial
interface
·
Myometrial cysts in up to 50% , Usually subendometrial
Location
·
Diffuse or asymmetric myometrial involvement
– Superficial type: Involving
< 1/3 of myometrial thickness
– Deep type: Invasion >
1/3 of myometrial thickness
– When asymmetric, posterior
> anterior myometrium
– May be more focal and
mass-like, resulting in adenomyoma , Often near endomyometrial junction
Morphology
○ If confluent/diffuse, globular enlarged uterus
with smooth external contour
○ If focal, commonly elliptical myometrial mass
Ultrasonographic Findings
1. Size : Globular uterine enlargement
Sagittal TAS demonstrates globular shape of the uterus |
Sagittal TVS shows diffuse myometrial heterogeneity. In addition, the endometrium is poorly defined. |
Transabdominal US shows uterine enlargement and diffuse heterogeneity of the uterine parenchyma with nonvisualization of the endometrium.
|
2.
Echo texture : Heterogeneous myometrial echotexture - Hypoechoic
smooth muscle hyperplasia - Echogenic
linear striations due to endometrial extension into myometrium
Longitudinal transvaginal US demonstrates asymmetric posterior greater than anterior linear bands of echogenicity and shadowing without a focal mass, consistent with adenomyosis. |
3.
Endomyometrial interface : Loss due to thickening of junctional zone
Longitudinal transvaginal US demonstrates asymmetric posterior myometrial thickening with subtle shadowing without a defined mass. The endomyometrial border is partially obscured . |
4. Subendometrial echogenic linear striations
Transverse transabdominal US demonstrates poor delineation of the endomyometrial border , and diffuse myometrial thickening with areas of bandlike shadowing . |
5.
Subendometrial echogenic nodules
Longitudinal transvaginal US demonstrates subtle invaginations of the endometrium into the myometrium , diagnostic of adenomyosis. Presence of a subendometrial cyst is also highly specific |
6.
Cysts within myometrium : Anechoic, usually subendometrial , Highly specific for diagnosis . Distinguished
from uterine veins, which are peripheral, have color flow Disordered or uncircumscribed
myometrial vascular pattern on color Doppler
Sagittal TVS reveals multiple small cysts in the myometrium |
7. Tender with probe pressure
8. If mass-like, difficult to differentiate from leiomyoma but less
distinct - Often emanates from endomyometrial junction - Penetrating vessels without mass effect on
color Doppler - Not calcified
NB. Focal
adenomyosis is usually the form most difficult to distinguish from leiomyomas.
Distinct borders are typical of leiomyomas, whereas indistinct borders suggest
adenomyosis. It has been suggested that color or power Doppler may be helpful
in making the distinction, with adenomyosis tending to have more central vascularity
and leiomyomas tending to have mostly peripheral vascularity. However, the
reliability of Doppler findings to make this distinction has not been
adequately evaluated. In patients in whom one is uncertain whether the findings
represent Adenomyosis Or leiomyomas Or both (when making This distinction Is important
For clinical care), MRI is helpful.
Although adenomyosis is
usually considered to occur mostly in premenopausal women, it can be seen in
postmenopausal women.
9. focal adenomyosis : when
involving only part of the myometrium
Sagittal
TAS shows asymmetrical myometrial thickness,
with the posterior myometrium thicker and heterogeneous compared with the
anterior myometrium..
|
10. adenomyoma : when more distinct as focal
11. juvenile cystic adenomyoma : rarely form , can
appear as an isolated cystic mass, larger than the small myometrial cysts
typically seen in Adenomyosis .
12.
9% of affected patients have normal ultrasound findings.
MR Findings
•
Thickened junctional zone (> 12 mm) on T2WI, diffuse or focal
•
Focal areas of T2 increased signal due to dilated endometrial
glands
•
May have focal areas of T1 increased signal due to hemorrhage
•
If mass-like, difficult to differentiate from leiomyoma : Often near junctional zone - T2 hypointense due to smooth muscle hyperplasia - Similar enhancement patterns as leiomyoma
Axial T2WI MR in the same patient demonstrates
diffuse but asymmetric thickening of the fundal junctional zone with subendometrial cysts , diagnostic of adenomyosis.
|
Fluoroscopic Findings
•Hysterosalpingography (HSG)
○ Small diverticula extending from endometrial
cavity
Saline-Infused Hysterosonography
•
Saline and bubbles may fill linear tracks in myometrium, producing
"myometrial cracks"
SHG may show communication between
the lesions of adenomyosis and the endometrial cavity.
Best imaging tool
○ US best initial study for
patients with pelvic symptoms
. Transvaginal ultrasound
best to evaluate endomyometrial interface
○ MR for equivocal, difficult, or
nondiagnostic cases
–
T2WI best to evaluate junctional zone
–
Less limited by size of uterus and patient
–
More comprehensive evaluation of fibroid burden
–
Not limited by shadowing
Protocol advice
○ Cine clips with slow sweep are helpful for
subtle findings such as streaky shadowing and small myometrial cysts
○ Evaluate for uterine tenderness
Differential Diagnosis
Leiomyoma
•
US: Well-defined mass in submucosal, subserosal, or mural location , it May be
difficult to distinguish from adenomyoma
•
Often multiple, with lobular external uterine contour
•
Can be calcified with peripheral vascularity
•
MR: Low T1/T2 signal with nonthickened junctional zone
Diffuse Myometrial Hypertrophy
•
Endometrial-myometrial borders maintained
•
Junctional zone remains well defined
•
Heterogeneous myometrium without other findings
Endometrial Cancer
•
Irregularly thickened heterogeneous endometrium
•
Possible invasion into myometrium with loss of endomyometrial interface
Metastasis to Uterine Corpus
•
Rare, most commonly breast, gastric cancers and lymphoma
•
Lymphoma rarely primary : Hypoechoic infiltration, preserves contour with
less mass
effect
on endomyometrial interface
Endometrial Hyperplasia
•
Thickened endometrium, may have cystic appearance
• Typically preserved
endomyometrial interface
PATHOLOGY
• Etiology
·
Ectopic endometrial tissue within myometrium
·
the histologic diagnosis of adenomyosis requires the presence of
endometrial glands or stroma to be located more than 2.5 or 3 mm away from the
outer edge of the endometrium.
·
Reactive hypertrophy and hyperplasia of surrounding smooth
muscle
·
Etiology poorly understood, but may involve invagination of
endometrium directly into myometrium vs. de novo development from müllerian
rests
• Associated abnormalities
○
Endometriosis : ; 22% to 49%
○ Leiomyomas
: Adenomyosis and leiomyomas
often coexist; 15% to 57% of women with leiomyomas are reported to also have Adenomyosis
in surgical series. It can sometimes be difficult to distinguish these two entities, or determine if both are
present, by ultrasound
○ Tamoxifen
: Women with breast cancer who
are treated with tamoxifen have a higher incidence of adenomyosis. It may be
that the estrogen agonist effects of tamoxifen on endometrial tissue cause
adenomyosis or reactivate preexisting adenomyosis.
CLINICAL ISSUES
Presentation
○ Diffusely enlarged uterus, may be tender
○ Often associated with menorrhagia : Less
commonly dysmenorrhea or metrorrhagia
○ Commonly associated with endometriosis
○ Controversial association with infertility
○ Often mistaken for fibroids given similar
symptoms and ultrasound findings
• Age
○ Pre- or perimenopausal
• Epidemiology
○ Often have coexistent leiomyomas
○ Most commonly multiparous
○ Association with cesarean sections
○ The prevalence Of Adenomyosis Is uncertain; There are
Widely varying Estimates from 5% to 70%.
Treatment
•
Medical treatment with oral contraceptives or gonadotropin releasing hormone
agonists to control symptoms
•
Adenomyosis cannot be resected
•
Hysterectomy is definitive treatment
•
Uterine artery embolization is effective alternative treatment : Results not as
reproducible as for leiomyoma
Consider
•
Enlarged, tender uterus in patient with menorrhagia
denomyosis
Image Interpretation Pearls
•
Loss of endomyometrial interface due to thickening of junctional zone
•
Abnormal myometrial echogenicity, most commonly hypoechoic, due to smooth
muscle hyperplasia
•
Echogenic linear striations due to endometrial extension into myometrium
•
If findings are equivocal, obtain MR to evaluate for thickened junctional zone
(> 12 mm is diagnostic), However,
diagnosis can be made at lower threshold if T1/T2-bright foci or linear high T2
signal striations are Present
Well done..
ReplyDelete