it is characterized by the diversion of portal venous blood away from the liver , by either end - to - side or side - to - side shunt . a two - and - half - year - old child presented with respiratory distress , poor growth , and loss of appetite for 2 months . computed tomography ( ct ) showed mild cardiomegaly with collapse / consolidation of bilateral lung lobes . incidentally , there was the presence of an end - to - side shunt between the right branch portal vein ( pv ) and the inferior vena cava ( ivc ) with fusiform aneurysmal dilatation of the pv continuing into the left branch , which abruptly ended after a short distance . there was aplasia of the right branch of the pv [ figures 1 and 2 ] . the hepatic artery appeared normal . the splenic and superior mesenteric veins had normal orientation , and these vessels joined to form the main pv . a diagnosis of congenital extrahepatic portocaval shunt ( ceps ) ( abernethy malformation type 1 ) with pv aneurysm was made . since the patient was asymptomatic and liver enzymes were normal , the patient was advised follow - up . there was the presence of end - to - side shunt between the right branch of pv and the ivc ( solid thick arrow ) , fusiform aneurysmal dilatation of the pv , which was continuing into the left branch ( thin arrow ) coronal multiplanar reconstruction ( mpr ) shows the presence of end - to - side shunt between the right branch pv and the ivc ( b ) ( arrow ) with fusiform aneurysmal dilatation of the pv ( a ) . the portal venous system and ivc develop between the 4th and 10th weeks of embryonic life by selective apoptosis of some portions of the vitelline , which may lead to the potential for congenital portosystemic shunts . type i ceps ( congenital absence of the pv ) is an end - to - side shunt between pv and the systemic circulation . here all the splanchnic venous return enters the systemic circulation , and the liver is not perfused with portal venous blood at all . type ii ceps is a partial side - to - side shunt between the portal and systemic vein , where only a fraction of the splanchnic venous return bypasses the liver parenchyma . ceps are also associated with an increased frequency of hepatic neoplasms.[37 ] it has been proposed that the diversion of hepatotropic substances in the splanchnic venous blood , such as insulin and glucagon , away from the liver results in alterations of development , function , and regenerative capacity of the liver . this diversion , along with increased arterial hepatic flow , may contribute to the development of hepatic neoplasms . currently , a diagnosis of abernethy malformation is usually made by noninvasive cross - sectional imaging techniques such as ultrasound , ct , or mri , which show the shunt and any intrahepatic pv branches . however , liver biopsy may be necessary in patients with suspected type 1 malformation since an occasional patient may have small pv radicles which can not be seen on ultrasound but can be observed on liver biopsy . pv aneurysm is a rare clinical entity having a focal fusiform or saccular dilatation of more than 20 mm . aneurysms of the pv may occur either proximally at the junction of the superior mesenteric vein and splenic vein or more distally in the pv radicals . congenital origin is suggested based on the discovery of variations in the embryologic development of the pv and may be associated with multiple vascular malformations . the origin of acquired pv aneurysms is more commonly secondary to cirrhosis and other hepatic diseases . pancreatitis can be included as an extrahepatic cause . in the majority of cases , patients are clinically asymptomatic . the majority of patients with abernethy malformation have other associated anomalies such as liver and cardiac abnormalities . described a case of 24-year - old man having ceps type-2 with pv aneurysm during an investigation for nonspecific abdominal pain . determining the patients with type i malformation need clinical , biochemical , and imaging follow - up . however , those patients with type 2 malformations need surgery or percutaneous transcatheter coil placement . in conclusion , although ceps is a rare anomaly , it must be recognized early to prevent the consequences of metabolic derangements by appropriate surgical treatments . , the detection of tiny intrahepatic portal venous radicals may be beyond the resolution limits of the available imaging methods . the limitation of imaging in determining the type of shunt in some cases should be recognized , and a histopathological confirmation of the type of shunt may be crucial in deciding the treatment course .
abernethy malformation is an extremely rare anomaly of the splanchnic venous system . 
 we describe multidetector computed tomography findings of an incidentally detected abernethy malformation with portal vein aneurysm in a two - and - half - year old child . 
 the computed tomography scan was performed for the evaluation of respiratory distress , poor growth , and loss of appetite .