Which classical abnormality is seen in liver?
Intrahepatic cystic areas, which appear to communicate with biliary tree - diagnosis of Caroli's disease is almost certain. (c.f. von Meyerburg hamartomas will be relatively smaller than these cysts)
Which other autosomal recessive condition is noted in the case?
Autosomal recessive polycystic kidney is also seen.
Considering the age of patient and the CT images, what seems to be the primary concern among two conditions?
While ARPKD is the primary concern in neonatal or early childhood presentation, hepatic fibrosis dominates in juvenile presentation. As seen in this case, features of portal hypertension are quite obvious with massive splenomegaly and left lobe hypertrophy.
Enlarged kidneys in addition to bilateral multiple small cystic attenuation areas, suggesting ARPKD.
Multiple hypodense cystic areas are seen in right lobe of liver, which appear to be of similar attenuation to few linear dilated intrahepatic biliary radicals. Some of the lesions show a central enhancing focus ("central dot sign"), suggesting Caroli syndrome.
Associated findings such as atrophied right lobe, left lobe hypertrophy and massive splenomegaly (due to portal hypertension).
Large number of varices around the spleen.