Diagnostic Ultrasound - Abdomen and Pelvis

Peritoneal Inclusion Cyst
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Diagnoses: Female Pelvis
Hydrosalpinx
• Serpiginous morphology
○ May look multiloculated in short axis
• Look for mural nodules or cogwheel
• Adjacent normal ovary
• Bilateral common
Paraovarian Cyst
• Unilocular adnexal cyst
○ Anechoic with no septations
○ Well-defined cyst wall
• Rarely multiple
• Does not resolve with time
• Separate from ovary
Endometriosis
• Endometrioma has diffuse internal low-level echoes
• More complex multilocular appearance
• May have punctate mural echogenic foci
• Different history: Cyclical pain or infertility
• Can be seen in association with PIC
Pseudomyxoma Peritonei
• Mucinous fluid with low-level echoes
• Mass effect with scalloping of liver and spleen
• Thicker irregular septa
Peritoneal Carcinomatosis
• Ascites, peritoneal thickening and nodules, omental cake
Lymphangioma/Mesenteric Cyst
• Congenital infiltrative multilocular cystic peritoneal lesion
• Different age group and history
PATHOLOGY
General Features
• Etiology
○ PIC development requires functioning ovary and
peritoneal adhesions
○ Ovaries normally produce peritoneal fluid
○ In patients with adhesions from prior pelvic surgery,
inflammation, or endometriosis, there is impaired
absorption resulting in loculated peritoneal fluid
○ Also seen with peritoneal dialysis, inflammatory bowel
disease, pelvic inflammatory disease
Microscopic Features
• Septations
○ Single layer of flat to cuboidal mesothelial cells
– Benign mesothelial proliferation
○ Occasional squamous metaplasia
• No true cyst wall
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Pelvic pain
○ Palpable mass
○ Abdominal distension
○ Incidentally noted on imaging
• Other signs/symptoms
○ Pressure symptoms: Urinary frequency or hesitancy,
constipation
Demographics
• Age
○ Almost exclusively premenopausal women
– Functioning ovary required for PIC formation
Natural History & Prognosis
• Indolent course: May grow, remain stable, or regress
• Tend to recur after drainage
Treatment
• Hormonal therapy: Suppression of ovulation
• Ultrasound- or CT-guided drainage
○ ± sclerosant
• Surgery: Laparoscopic or open, avoid if possible
○ 30-50% recurrence risk with surgical resection
DIAGNOSTIC CHECKLIST
Consider
• PIC in appropriate clinical setting
○ Premenopausal patient with other pelvic pathology
– Endometriosis
– Surgery
– Trauma
– PID
• Differentiating from ovarian malignancy may be difficult
○ Must have high level of clinical suspicion for PIC
○ PIC: Absence of solid components and normal ovary
Image Interpretation Pearls
• Do not diagnose PIC in postmenopausal patient
○ Ovarian cancer much more likely
• Must see otherwise intact ovary
○ Ovary may be distorted
○ May be located at periphery of mass
• Ovarian neoplasm morphology
○ Thicker, more irregular septations
○ Mural nodules or papillary excrescences
○ More complex fluid
SELECTED REFERENCES
1. Bharwani N et al: Peritoneal pseudocysts: aetiology, imaging appearances,
and natural history. Clin Radiol. 68(8):828-36, 2013
2. Veldhuis WB et al: Peritoneal inclusion cysts: clinical characteristics and
imaging features. Eur Radiol. 23(4):1167-74, 2013
3. Laing FC et al: US of the ovary and adnexa: to worry or not to worry?
Radiographics. 32(6):1621-39; discussion 1640-2, 2012
4. Moyle PL et al: Nonovarian cystic lesions of the pelvis. Radiographics.
30(4):921-38, 2010
5. Vallerie AM et al: Peritoneal inclusion cysts: a review. Obstet Gynecol Surv.
64(5):321-34, 2009
6. Tamai K et al: MR features of physiologic and benign conditions of the ovary.
Eur Radiol. 16(12):2700-11, 2006
7. Guerriero S et al: Role of transvaginal sonography in the diagnosis of
peritoneal inclusion cysts. J Ultrasound Med. 23(9):1193-200, 2004
8. Savelli L et al: Transvaginal sonographic appearance of peritoneal
pseudocysts. Ultrasound Obstet Gynecol. 23(3):284-8, 2004
9. Hanbidge AE et al: US of the peritoneum. Radiographics. 23(3):663-84;
discussion 684-5, 2003