Amylase level in extrahepatic bile duct in adult patients with choledochal cyst plus anomalous pancreatico-biliary ductal union

Abstract

Aim: To investigate the relationship between pancreatic amylase in bile duct and the clinico-pathological features in adult patients with choledochal cyst and anomalous pancreatico-biliary ductal union (APBDU).

Methods: From 39 patients who underwent surgery for choledochal cyst between March 1995 and March 2003, we selected 15 adult patients who had some symptoms and were radiologically diagnosed as APBDU, and their clinico-pathological features were subsequently evaluated retrospectively. However, we could not obtain biliary amylase in all the patients because of the surgeon's slip. Therefore, we measured the amylase level in gall bladder of 10 patients and in common bile duct of 11 patients.

Results: Levels of amylase in common bile duct and gall bladder ranged from 11,500 to 212,000 IU/L, and the younger the patients, the higher the biliary amylase level (r = -0.982, P<0.01). Pathologically, significant correlation was found between the size of choledochal cyst and the grade of inflammation (r = 0.798, P<0.01). And, significant correlation was found between the level of amylase in gall bladder and the grade of hyperplasia. On the other hand, there was no correlation to the age of symptomatic onset or inflammatory grade (r = 0.743, P<0.05). Level of lipase was elevated from 6,000 to 159,000 IU/L in bile duct and from 14,400 to 117,000 IU/L in the gall bladder; however, there was no significant correlation with age or clinico-pathological features.

Conclusion: The results support the notion that amylase has a particular role in the onset of symptoms, and suggest that a large amount of biliary amylase induces early onset of symptom, thereby making early diagnosis possible.

Figure 1

Endoscopic retrograde cholangiopancreatogram of choledochal cyst and microscopic change of extrahepatic bile duct. A: Todani type I and APBDU; B: Todani type IVa and APBDU; C: infiltration of small number of lymphocytes (inflammatory grade I); D: extensive infiltration of lymphocytes with surface erosion (inflammatory grade III); E: papillary epithelial growth, less than one-third (hyperplasia grade I); F: papillary epithelial growth, more than two-thirds (hyperplasia grade III).

Figure 2

Correlation between the age of symptomatic onset and bile duct amylase (n = 11) or gall bladder amylase (n = 10). A: There was highly significant correlation between age and level of amylase in bile duct; that is, the level of biliary amylase decreased with increasing age of onset (r = –0.982, P<0.01); B: in gall bladder (r = –0.636, P<0.05).

Figure 3

Correlation between grade of inflammation and size of cyst (n = 14). A: There was significant correlation between inflammation grade and size of choledochal cyst (r = 0.798, P<0.01); B: When the size was grouped by 4 cm, statistical significance was more remarkable (P<0.01).

Figure 4

Relationship between the age of symptomatic onset and grade of inflammation (n = 14). There was no correlation between the age and the grade of inflammation (r = 0.205, P>0.05).

Figure 5

Correlation between grade of hyperplasia and gall bladder amylase (n = 11). There was significant correlation between the grade of hyperplasia and gall bladder amylase; that is, the grade of hyperplasia increased with increasing the gall bladder amylase (r = 0.743, P<0.05).