Diagnostic Ultrasound - Abdomen and Pelvis

Ciliated Hepatic Foregut Cyst
TERMINOLOGY
Abbreviations
• Ciliated hepatic foregut cyst (CHFC)
Definitions
• Foregut developmental malformation in liver
IMAGING
General Features
• Best diagnostic clue
○ Subcapsular cystic lesion located within or close to
segment IV of liver
• Location
○ Within or near medial segment of left lobe of liver
(segment IV)
○ Either subcapsular or beneath Glisson capsule
• Size
○ Average: 3.6 cm (range: 1.1-13 cm)
• Morphology
○ Typically unilocular, rarely multilocular
○ Round or ovoid cystic lesion with smooth, well-defined
walls
Ultrasonographic Findings
• Single unilocular cyst
• May contain internal echogenic foci
• Posterior acoustic enhancement
CT Findings
• NECT:Variable depending on fluid composition
○ Mostly hypoattenuating; sometimes iso- or
hyperattenuating
• CECT:No enhancement
MR Findings
• T1WI:Frequently hyperintense due to mucin
○ Depends on viscosity, mucin density, presence or
absence of cholesterol and calcium crystals
• T2WI:Brightly hyperintense
Imaging Recommendations
• Best imaging tool
○ Ultrasound is suggestive of diagnosis; correlation with CT
or MR may be helpful
DIFFERENTIAL DIAGNOSIS
Complicated Hepatic Cyst
• May contain thin septa, internal debris, or fluid-debris level
Biliary Cystadenoma/Cystadenocarcinoma
• Usually multilocular or with complex septations or mural
nodules
• Predominantly seen in women
Biloma
• Usually results from trauma, including prior surgery
Hematoma
• Due to hepatic trauma
• Echogenicity evolves over time
PATHOLOGY
General Features
• Etiology
○ Thought to arise from detached outpouching of hepatic
diverticulum or adjacent enteric foregut
– Share common embryological origin with bronchial
cyst and esophageal cyst
Gross Pathologic & Surgical Features
• Cyst contents:Mostly viscous or mucinous
○ Infantile form: Bilious fluid with direct communication
with bile ducts
Microscopic Features
• Similar to bronchogenic and esophageal cysts
• Lined, ciliated, pseudostratified, mucin-secreting columnar
epithelium
• Cyst wall contains abundant smooth muscle fibers
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Asymptomatic and incidentally found by imaging
• Other signs/symptoms
○ Right upper quadrant pain
– Small cyst: Subcapsular location may stretch Glisson
capsule
○ Abdominal mass secondary to enlarged cystic swelling
○ Large cysts may cause obstructive jaundice or portal
hypertension secondary to compression effects
Demographics
• Age:Middle-aged
• Gender:Slight male predominance (1.1:1)
• Prevalence:Very rare but increasingly diagnosed
Natural History & Prognosis
• Slowly growing congenital cyst
• Clinical course usually benign
• 3% risk of malignant transformation: Squamous cell
carcinoma, usually in setting of large cyst
Treatment
• Surgical excision or enucleation irrespective of size so as to
eliminate subsequent cancer risk
• Infantile CHFC: Liver resection and closure of biliary
communication
DIAGNOSTIC CHECKLIST
Consider
• Rule out other cystic lesions and solid hypovascular
tumorous lesions in liver
Image Interpretation Pearls
• Single subcapsular unilocular cystic lesion in or near hepatic
segment IV with variable internal contents
SELECTED REFERENCES
http://radiologyebook.com/
1. Sharma S et al: Ciliated hepatic foregut cyst: an increasingly diagnosed
condition. Hepatobiliary Pancreat Dis Int. 7(6):581-9, 2008
Diagnoses: Liver
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