Diagnostic Ultrasound - Abdomen and Pelvis

Adenomyosis
Diagnoses: Female Pelvis
TERMINOLOGY
• Ectopic endometrial tissue within myometrium with
adjacent smooth muscle hyperplasia
• May have diffuse involvement or focal mass (adenomyoma)
IMAGING
• Best diagnostic clue: Uterine enlargement with poor
definition of endometrial-myometrial interface
• Ultrasound
○ Globular uterine enlargement
○ Heterogeneous myometrial echotexture
○ Loss of endomyometrial interface due to thickening of
junctional zone
○ May be asymmetric; if mass-like, often emanates from
endomyometrial junction
– May be difficult to differentiate from leiomyoma
• T2WI MR: Thickened junctional zone > 12 mm ± T2-bright
foci
KEY FACTS
TOP DIFFERENTIAL DIAGNOSES
• Leiomyoma
• Diffuse myometrial hypertrophy due to parity
• Endometrial cancer
• Metastasis to uterine corpus
• Endometrial hyperplasia
CLINICAL ISSUES
• Commonly associated with endometriosis
• Uterine artery embolization may be effective
• Hysterectomy definitive treatment
DIAGNOSTIC CHECKLIST
• Abnormal myometrial echogenicity, most commonly
hypoechoic, due to smooth muscle hyperplasia
• Loss of endomyometrial interface due to thickening of
junctional zone
• If findings are equivocal, obtain MR to evaluate for
thickened junctional zone
(Left) Longitudinal
transvaginal US demonstrates
asymmetric posterior greater
than anterior linear bands of
echogenicity and shadowing
st without a focal mass,
consistent with adenomyosis.
(Right) Longitudinal
transvaginal US demonstrates
asymmetric posterior
myometrial thickening with
subtle shadowing st without
a defined mass. The
endomyometrial border is
partially obscured ſt.
(Left) Transverse
transabdominal US
demonstrates poor delineation
of the endomyometrial border
st, and diffuse myometrial
thickening with areas of bandlike
shadowing ſt. (Right)
Longitudinal transvaginal US
demonstrates subtle
invaginations of the
endometrium into the
myometrium ſt, diagnostic of
adenomyosis. Presence of a
subendometrial cyst is also
highly specific.
736