Definition/General
Introduction:
Umbilical cord cysts are fluid-filled cavities within the umbilical cord that occur in 0.4-3.4% of pregnancies
They are classified as true cysts (lined by epithelium) or pseudocysts (no epithelial lining)
Most are benign findings but may be associated with chromosomal abnormalities or fetal anomalies.
Origin:
True cysts originate from remnants of embryonic structures such as allantois or omphalomesenteric duct
Pseudocysts result from focal degeneration or liquefaction of Wharton's jelly
May develop from vascular accidents or cord compression
Developmental arrest may contribute to formation.
Classification:
Classified as true cysts (epithelium-lined) or pseudocysts (no epithelium)
Allantoic cysts: derived from allantois
Omphalomesenteric cysts: from vitelline duct remnants
Simple pseudocysts: Wharton's jelly degeneration
Size classification: small (<1 cm) versus large (>1 cm).
Epidemiology:
Incidence: 0.4-3.4% of pregnancies
More common in first trimester
Higher frequency with chromosomal abnormalities
Associated with 5-15% of fetal anomalies
No specific maternal age predilection.
Clinical Features
Presentation:
Usually asymptomatic
May cause cord compression if large
Associated with fetal anomalies in 10-20% cases
Chromosomal abnormalities in 5-10%
May resolve spontaneously.
Symptoms:
Fetal distress if cord compression occurs
Variable decelerations on monitoring
Oligohydramnios may be present
Intrauterine growth restriction possible
Emergency cesarean section rarely needed.
Risk Factors:
Advanced maternal age
Previous pregnancy losses
Family history of congenital anomalies
Maternal diabetes mellitus
Exposure to teratogens
Genetic syndromes.
Screening:
Ultrasound examination detects most cysts
First trimester screening may identify early cysts
Serial monitoring for size changes
Detailed anomaly scan recommended
Genetic counseling if associated anomalies.
Master Umbilical Cord Cyst Pathology with RxDx
Access 100+ pathology videos and expert guidance with the RxDx app
Gross Description
Appearance:
Fluid-filled cavity within umbilical cord
Size ranges from few millimeters to several centimeters
Unilocular or multilocular
Clear or slightly turbid fluid contents.
Characteristics:
Smooth cyst wall
May be single or multiple
Located anywhere along cord length
Surrounding Wharton's jelly may be compressed or normal
Associated cord coiling abnormalities possible.
Size Location:
Size: typically 0.5-2 cm diameter
Location: any segment of umbilical cord
Fetal end more common than placental end
May be central or eccentric within cord.
Multifocality:
Usually single cyst
Multiple cysts in 10-20% cases
May be associated with cord compression
Surrounding vessels usually normal.
Microscopic Description
Histological Features:
True cysts show epithelial lining (cuboidal or columnar)
Pseudocysts lack epithelium
Cyst wall composed of fibrous tissue
Wharton's jelly surrounds cyst
Normal umbilical vessels present.
Cellular Characteristics:
True cyst epithelium: cuboidal to columnar cells
Pseudocyst wall: compressed Wharton's jelly
Fibroblasts in cyst wall
Normal vessel architecture
No inflammatory infiltrate.
Architectural Patterns:
Unilocular most common
Smooth cyst wall
Surrounding Wharton's jelly compressed
Normal three-vessel cord pattern maintained
No evidence of cord torsion.
Grading Criteria:
Classification by epithelial lining presence
Size measurement
Number of cysts
Associated cord anomalies assessment
Vessel integrity evaluation.
Immunohistochemistry
Positive Markers:
Cytokeratin positive in true cyst epithelium
EMA may be positive in epithelial cells
Vimentin in stromal components
CD31 highlights vessels
Smooth muscle actin in vessel walls.
Negative Markers:
Cytokeratin negative in pseudocysts
Mesothelial markers typically negative
Endothelial markers negative in cyst lining
No specific pattern for pseudocysts.
Diagnostic Utility:
Distinguishes true from pseudocysts
Confirms epithelial nature
Excludes other lesions
Identifies vessel integrity
Research applications for cyst origin.
Molecular Subtypes:
No specific molecular classification
Developmental markers may be present
Normal expression patterns
Morphological assessment remains primary diagnostic tool.
Molecular/Genetic
Genetic Mutations:
Associated with chromosomal abnormalities in 5-10% cases
Trisomy 18 most common
Turner syndrome association
Single gene defects rare
Developmental gene variants possible.
Molecular Markers:
Normal developmental markers
Epithelial differentiation markers in true cysts
Wharton's jelly components normal
Vascular markers preserved.
Prognostic Significance:
Generally benign condition
Association with anomalies affects prognosis
Large cysts may cause complications
Resolution common in pregnancy
Genetic counseling if syndromic features.
Therapeutic Targets:
No specific therapeutic interventions
Monitoring recommended
Genetic counseling important
Delivery planning based on associated findings.
Differential Diagnosis
Similar Entities:
Cord hematoma
Cord edema
Urachal cyst remnants
Wharton's jelly myxoma
Vascular malformations.
Distinguishing Features:
Cyst: fluid-filled cavity
Cyst: well-defined wall
Hematoma: blood products
Edema: diffuse swelling
Myxoma: solid mucoid mass
Malformation: vascular pattern.
Diagnostic Challenges:
Distinguishing true from pseudocysts
Size significance assessment
Associated anomaly detection
Clinical correlation importance
Resolution monitoring.
Rare Variants:
Giant cord cysts (>5 cm)
Multiple cyst syndrome
Cysts with unusual contents
Associated teratoma
Cysts in multiple pregnancy.
Sample Pathology Report
Template Format
Sample Pathology Report
Complete Report: This is an example of how the final pathology report should be structured for this condition.
Specimen Information
Umbilical cord measuring [X] cm with cystic lesion
Cyst Description
Cyst: [size] cm, [location], [single/multiple], [unilocular/multilocular]
Cyst Contents
Contents: [clear/turbid] fluid, [volume if measured]
Microscopic Findings
Cyst wall: [epithelium-lined/no epithelium], [tissue composition]
Vessel Assessment
Umbilical vessels: [normal/compressed], [three-vessel/two-vessel] cord
Associated Findings
Associated findings: [present/absent] other cord anomalies
Clinical Significance
Clinical significance: [benign finding/requires follow-up], genetic counseling [recommended/not indicated]
Final Diagnosis
Umbilical cord [true cyst/pseudocyst], [size] cm