Diagnostic Ultrasound - Abdomen and Pelvis

Endometrioma
Diagnoses: Female Pelvis
– Calcification (teeth)
– Focal echogenicity with shadowing along cyst wall
○ Liquefied fat
– Hyperechoic, dirty shadowing, "tip of the iceberg" sign
○ Fat-fluid level
– Echogenic fluid on top of hypoechoic fluid (floating
fat)
○ Hair: Thin echogenic lines and dots
• 20-30% bilateral
• Symptomatic if rupture or torsion
Cystic Neoplasm
• Typically postmenopausal
• Multilocular mass
• Thick septations
• Wall nodularity
• Blood flow in septations and nodules
• Associated ascites
• More likely to be unilateral mass
PATHOLOGY
General Features
• Etiology
○ Retrograde menstruation (RM)
– Metastatic implantation
– 2° to hematogenous or lymphatic spread
○ Metaplasia of coelomic epithelium
– Peritoneal cells become endometrial cells
○ Induction theory
– Combination of previous 2 theories
– RM induces metaplasia
○ Abnormal immunity
– RM occurs in majority of women but implantation of
functioning endometrium is rare
– ↓ immunity results in implantation
• Associated abnormalities
○ Adhesions
○ Bowel, ureter, bladder involvement
○ Endometriosis can spread outside of pelvis
Gross Pathologic & Surgical Features
• Chocolate cyst
○ Dark brown viscous blood
• Endometriotic implant appearance variable
○ Immature foci are pale yellow or pink
○ Mature foci are dark brown or white scars
Microscopic Features
• Endometrial glands and stroma
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Infertility
○ Cyclical or chronic pain
○ Palpable mass
○ Incidentally noted mass on ultrasound
• Other signs/symptoms
○ Unusual symptoms for atypical locations
– Gastrointestinal bleeding
– Ureteral obstruction
– Pneumothorax
– Seizure
Demographics
• Age
○ Women of childbearing age
○ Mean age at diagnosis: 25-29 years
• Epidemiology
○ Overall prevalence 5-10%
– 4% of all tubal ligation cases
– 20% of infertility cases
– 25% of chronic pelvic pain cases
Natural History & Prognosis
• Burns out with menopause
○ May remerge with estrogen replacement therapy
Treatment
• Medical treatment
○ Hormonal manipulation of menstrual cycle
○ Best evidence for using levonorgestrel-releasing IUD and
GnRH analogues to decrease pain
• Conservative surgery
○ Laparoscopic: Ablation, excision of implants or
endometrioma cyst wall
○ Reproductive function retained
○ 30-40% recurrence rates
• Definitive surgery
○ Hysterectomy and oophorectomy
○ May recur with exogenous estrogen
• Infertility from endometriosis
○ Conservative surgery increases spontaneous pregnancy
and live birth rates
○ Improves assisted reproductive techniques
○ Monthly fecundity rates of 9-18%
DIAGNOSTIC CHECKLIST
Consider
• Endometrioma if unilocular adnexal cyst with diffuse lowlevel
echoes
Image Interpretation Pearls
• Endometrioma can mimic dermoid and neoplasm
• Multiple lesions are common
• MR findings more specific than ultrasound
SELECTED REFERENCES
1. Brown J et al: Endometriosis: an overview of Cochrane Reviews. Cochrane
Database Syst Rev. 3:CD009590, 2014
2. Groszmann Y et al: Decidualized endometrioma masquerading as ovarian
cancer in pregnancy. J Ultrasound Med. 33(11):1909-15, 2014
3. McDermott S et al: MR imaging of malignancies arising in endometriomas
and extraovarian endometriosis. Radiographics. 32(3):845-63, 2012
4. Siegelman ES et al: MR imaging of endometriosis: ten imaging pearls.
Radiographics. 32(6):1675-91, 2012
5. Chamié LP et al: Findings of pelvic endometriosis at transvaginal US, MR
imaging, and laparoscopy. Radiographics. 31(4):E77-100, 2011
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