Ectopic endometrial tissue within myometrium with adjacent smooth muscle hyperplasia

Globular uterine enlargement, asymmetric myometrial thickening

Poor definition of endometrial-myometrial interface/thickening of junctional zone

Heterogeneous myometrial echotexture

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  Echogenic linear striations due to endometrial extension into myometrium

Focal mass (adenomyoma): Less common

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  Emanates from endomyometrial junction, difficult to differentiate from leiomyoma

Myometrial cysts in up to 50%: Highly specific for diagnosis

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  Anechoic, usually subendometrial

Disordered or uncircumscribed myometrial vascular pattern on color Doppler

Hysterosonography: Saline and bubbles may fill linear tracks in myometrium, producing “myometrial cracks”

3D ultrasound rendered in true coronal plane may accentuate endometrial contour abnormality and thickened junctional zone

MR for equivocal, difficult, or nondiagnostic cases

Leiomyoma

Diffuse myometrial hypertrophy due to parity

Endometrial cancer

Metastasis to uterine corpus

Endometrial hyperplasia

Pre- or perimenopausal, most commonly multiparous

Often presents with dysmenorrhea, menorrhagia, chronic pelvic pain, dyspareunia, infertility

Diffusely enlarged uterus, may be tender

Commonly coexists with endometriosis and leiomyomas

Association with cesarean sections

Hysterectomy definitive treatment

Uterine artery embolization may be effective

If findings are equivocal, obtain MR to evaluate for thickened junctional zone

Cine clips with slow sweep are helpful for subtle findings, such as streaky shadowing and small myometrial cysts

Evaluate for uterine tenderness