The Liver - Developmental Anomalies, Normal Variants, Congenital Abnormalities & Metabolic Disorders PDF

The Liver Developmental Anomalies, Normal Variants, Congenital Abnormalities and Metabolic Disorders QE II/Dalhousie School of Health Sciences DMUT 2000 – Topic 6 Developmental Anomalies Agenesis Anomalies of position Agenesis  Congenital a...

The Liver Developmental Anomalies, Normal Variants, Congenital Abnormalities and Metabolic Disorders QE II/Dalhousie School of Health Sciences DMUT 2000 – Topic 6 Developmental Anomalies Agenesis Anomalies of position Agenesis  Congenital absence of part or all of the liver  Types Complete (all lobes)  Incompatible with life Partial (RT, LT and/or caudate lobe)  Compensatory hypertrophy of remaining lobes  Normal LFTs Anomalies of Position  Situs Anomalies  Congenital Diaphragmatic Hernia (covered in DMUT 3000)  Omphalocele (covered in DMUT 3000) Both CDH and Omphalocele result in the liver herniating outside of the normal position CDH – Liver herniates through diaphragm into thoracic cavity Omphalocele – Liver herniates outside the abdominal cavity through a defect in the anterior abdominal wall Situs Anomalies  Situs inversus Complete mirror image reversal of heart and upper abdominal organs  Situs ambiguous (Heterotaxy) Right isomerism (Asplenia)  Midline liver, no spleen Left isomerism (Polysplenia)  Midline liver, multiple spleens Situs anomalies have an increased incidence of congenital heart defects Normal Variants Reidel’s lobe Caudate process Diaphragmatic slips Vascular anomalies Reidel’s Lobe  Tongue-like extension of the right lobe Liver seen inferior to lower pole of right kidney May extend to iliac crest  Incidence Females > males  Sonographic Appearance Similar to the rest of the liver Reidel’s Lobe Image retrieved from https://radiologykey.com/the-normal-hepato- biliary-system/ Image retrieved fromhttps://radiopaedia.org/articles/riedel- lobe-3 Caudate Process  Inferior appendage of the caudate lobe Between MPV and IVC  Sonographic Appearance Same as the rest of the caudate lobe  DDx Mass attached or adjacent to the liver or pancreas Enlarged lymph node Diaphragmatic Slips  AKA – Accessory fissures (although not true congenital fissures) True accessory fissures are uncommon and are infolding of peritoneum  Invaginations of the diaphragm into the liver parenchyma  Sonographic Appearance Echogenic “pseudomass” Will elongate with change in transducer orientation  SAG to TR Also Rumack Fig 4-12 Vascular Anomalies  Variations of HA origin (45% of population) 1) LHA from LGA 2) RHA from SMA 3) CHA from SMA  Anomalies of the PV (Rare) Atresias, strictures, obstructing valves Absent RPV, or pars transversa  Anomalies of remaining branches  Anomalies of the HVs (Common) Accessory HV branches  Drain into another main HV or directly into IVC Absence of a HV Congenital Abnormalities Liver cysts Peribiliary cysts Autosomal dominant polycystic disease Biliary hamartomas Mesenchymal hamartomas Congenital Liver Cysts  Fluid-filled lesion with epithelial lining  Thought to result from anomalous development of hepatic ducts  Incidence Usually appear around middle age Common  2.5% of general population  7% in those >80 y.o. Congenital Liver Cysts  Clinical Symptoms  Treatment Asymptomatic Tend to recur if treated Large cysts may cause Only if symptomatic vague pain  Percutaneous aspiration Hemorrhage or infection  US or CT guided  Greater pain  Often recur  Fever  Cyst ablation  US or CT guided  Surgical excision Congenital Liver Cysts Sonographic Appearance  Solitary or multiple  DDx  Simple cyst criteria Abscesses  May be complexities Parasitic cysts Post-traumatic cysts Usually means there is (or has been previous) hemorrhage or infection Cystic neoplasms  Internal debris  Including malignancy  Septations  Thick wall May require further investigation  CT, MRI or follow-up US Also Rumack Fig 4-13 Peribiliary Cysts  Congenital liver cysts  Clinical Symptoms Located around porta hepatis or Asymptomatic RHD/LHD junction May cause biliary  Tend to occur in patients with obstruction (rare) severe liver disease  Pain  Jaundice  Result from obstructed glands around bile ducts Peribiliary Cysts Sonographic Appearance  Simple cyst criteria  Often are: Small