Diagnostic Ultrasound - Abdomen and Pelvis

Endometrial Carcinoma
TERMINOLOGY
Abbreviations
• Endometrial carcinoma (EC)
Definitions
• Malignant proliferation of abnormal endometrial glands
IMAGING
General Features
• Best diagnostic clue
○ Mass in endometrial cavity with internal color flow
○ Irregularly thickened endometrial echo complex in
postmenopausal patient with vaginal bleeding
• Location
○ Can invade myometrium, cervix, parametrial structures
• Morphology
○ Polypoid masses or diffuse endometrial thickening
Ultrasonographic Findings
• Grayscale ultrasound
○ Thickened endometrium
– Focal thickening more concerning than diffuse
– Areas of mixed echogenicity more suspicious than
homogeneous hyperechogenicity
○ Endometrial-myometrial interface
– Smooth margins in early stage disease (stage 1A)
– Disruption of subendometrial halo suggests
myometrial invasion (stage 1B)
○ Hematometros if obstruction of uterine cavity or cervix
• Pulsed Doppler
○ Not specific: Significant overlap with benign etiologies
• Color Doppler
○ Multiple feeding vessels
CT Findings
• Focal or diffuse endometrial thickening
• Centrally located uterine mass hypoenhancing to
myometrium
• Useful for assessment of lymphadenopathy and metastases
○ Limited in early disease detection and in local staging
MR Findings
• T1WI
○ Hypo- or isointense to normal
endometrium/myometrium
○ Hematometros is hyperintense
• T2WI
○ Hypo- or isointense to normal endometrium
○ Intact junctional zone excludes deep myometrial invasion
• DWI
○ Restricted diffusion in tumor and lymphadenopathy
• T1WI C+
○ Hypoenhancing relative to myometrium in early and
equilibrium phase
○ Myometrial invasion: Hypoenhancing tissue extending
through junctional zone
○ Distinguish enhancing tumor from nonenhancing
endometrial blood
• Loss of zonal anatomy is potential pitfall in postmenopausal
women, those on tamoxifen therapy
Nuclear Medicine Findings
• F-18 FDG PET is useful for detecting metastases,
surveillance for recurrence
Imaging Recommendations
• Best imaging tool
○ Transvaginal sonography (TVS) for initial detection
○ High resolution T2WI and C+ MR for local staging
○ CECT or MR (contrast enhanced and diffusion weighted)
to evaluate for lymphadenopathy, metastatic disease
• Protocol advice
○ Must see entire endometrium
– Measure on sagittal section of uterus at widest point
– Exclude hypoechoic inner myometrium in
measurement
– Exclude endometrial cavity fluid from measurement
○ If inadequate TVS (5-10%) → additional evaluation with
sonohysterography (SHG) or MR
○ In postmenopausal women bilayer thickness > 5 mm
merits biopsy
○ Saline-infusion sonohysterography (SHG) useful in triage
– Diffuse thickening: Blind endometrial biopsy
– Focal thickening: Hysteroscopic biopsy necessary to
ensure sampling of abnormal area
DIFFERENTIAL DIAGNOSIS
Endometrial Hyperplasia
• Imaging cannot differentiate hyperplasia from carcinoma,
particularly stage 1A
• More likely homogeneous thickening
Endometrial Polyp
• More likely to be focal oval or fusiform mass than diffuse
thickening
• Look for single feeding vessel in fibrovascular stalk
• Internal cystic components more likely than in carcinoma
Submucosal Fibroid
• Hypoechoic mass/masses in cavity
• Mass arises from myometrium, displaces but does not
expand endometrium
• SHG: "Rind" of endometrium covers fibroid surface
Uterine Sarcoma
• Usually larger, heterogeneous, more aggressive
• Much less common than uterine carcinoma
Adenomyosis
• Based in myometrium, can mimic stage 1B carcinoma with
extension into myometrium
• Myometrial/subendometrial cysts
• Bulky uterus with areas of acoustic shadowing
PATHOLOGY
General Features
• Etiology
○ Risk factors
– Obesity, diabetes, hypertension, chronic anovulation
– Polycystic ovarian syndrome: Controversial causative
association vs. 2 diseases with similar risk factors
– Prior pelvic radiation
Diagnoses: Female Pelvis
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