Diagnostic Ultrasound - Abdomen and Pelvis

Enlarged Uterus
Differential Diagnoses: Female Pelvis
DIFFERENTIAL DIAGNOSIS
Common
• Pregnancy/Normal Postpartum
• Complications of Pregnancy/Abnormal Postpartum
• Multiparous Patient
• Leiomyoma
• Adenomyosis
• Focal Myometrial Contraction
Less Common
• Endometrial Cancer
• Cervical Stenosis
• Cervical Mass
• Hematometrocolpos
Rare but Important
• Uterine Leiomyosarcoma
• Uterine Lymphoma
ESSENTIAL INFORMATION
Key Differential Diagnosis Issues
• Is the patient pregnant or recently pregnant?
• Are there signs of infection?
• Enlarged uterus without focal mass
○ Diffuse adenomyosis
○ Multiparous patient
• Multiple masses
○ Round, well-defined masses: Intramural leiomyomas
○ Ovoid, ill-defined masses: Focal adenomyosis
• Fluid in endometrial cavity causing uterine enlargement
○ Obstructed outflow secondary to cervical stenosis or
mass (carcinoma, leiomyoma)
○ Or secondary to congenital anomaly: Imperforate
hymen, vaginal septum, cloacal abnormality
• Ill-defined mass in uterine cavity: Endometrial cancer
Helpful Clues for Common Diagnoses
• Pregnancy/Normal Postpartum
○ Presence of gestational sac or fetus
• Complications of Pregnancy
○ Retained products of conception, clot, failed pregnancy,
molar pregnancy, endometritis
• Leiomyoma
○ Focal, well-defined hypoechoic masses
○ May have pseudocapsule
○ Lobulated contour of uterus
• Adenomyosis
○ Asymmetric myometrial thickening
○ Cystic spaces in endometrium and subendometrium
○ Alternating bands of increased through transmission and
shadowing
• Focal Myometrial Contraction
○ Focal bulge of myometrium during pregnancy, resolves
over time
○ Affects internal myometrial appearance more than
external contour
○ Disruption of hypoechoic subendometrial halo
○ Isoechoic to surrounding myometrium
Helpful Clues for Less Common Diagnoses
• Endometrial Cancer
○ Patient typically presents with bleeding
○ Diffuse uterine enlargement
○ Ill-defined endometrium
• Cervical Stenosis
○ Patient with history of curettage or childbearing
○ Fluid in endometrial cavity, thin surrounding
endometrium with no focal lesion
• Cervical Mass
○ Hypoechoic, ill-defined mass with necrosis suggests
malignancy
○ Well-defined homogeneous mass suggests leiomyoma
• Hematometrocolpos
○ Hemorrhagic fluid in uterus &/or vagina
○ Acquired or congenital
Helpful Clues for Rare Diagnoses
• Uterine Leiomyosarcoma
○ Large heterogenous rapidly growing masses
(Left) Longitudinal
transabdominal ultrasound of
a patient with postpartum
endometritis shows an
enlarged uterus st with gas
and debris ſt in the
endometrial cavity. (Right)
Transverse color Doppler
ultrasound shows a large,
shadowing, painful subserosal
fibroid ſt. Despite patent
adjacent myometrial vessels
, there was no internal
color flow.
Complications of Pregnancy/Abnormal
Postpartum
Leiomyoma
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