Spontaneously ruptured choledochal cyst: Rare diagnosis on hepatic scintigraphy.

A 47-day-old female infant presented with congenital inguinal hernia, seizure on the 2(nd) day of life, fever, progressive jaundice, acholic stools and distension of abdomen. She was suspected to have choledochal cyst with extrahepatic biliary atresia (EHBA) and referred for an Hepatobiliary Tc-99m iminodiacetic acid (HIDA) scan. On HIDA scan, a functional diagnosis of ruptured choledochal cyst was made which was not possible on anatomical imaging like ultrasound (USG)/computed tomography (CT) scan. This was supported thereafter by bilious aspirate on abdominal paracentesis. Immediate laparotomy with T-tube insertion was done. The child improved dramatically after the procedure. Biliary peritonitis secondary to cyst perforation or rupture is a rare complication reported to occur in 1-2% cases of choledochal cyst. Early diagnosis and management is the key to reduce the morbidity and mortality.