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duodenal diverticulum was first reported by a french pathologist chomel in 1710   and was diagnosed radiologically by case   in 1913 .
duodenum is the second most common site of diverticula in alimentary tract after colon , followed by jejunum , ileum , and stomach [ 3 , 4 ] . although associated with complications like diverticulitis , perforation , obstruction , or haemorrhage , the majority of duodenal diverticula are asymptomatic [ 5 , 6 ] , more often coming as a surprise on gastrointestinal series .  
duodenal diverticula are found in 0.16 to 6% of upper gastrointestinal barium series and up to 23% of endoscopic retrograde cholangiopancreaticographies [ 6 , 7 ] .
however , reported incidence from cadaveric studies could be as high as 31.8% . in recent review of the literature
, there were a few cadaveric studies on the incidence of duodenal diverticulum throughout the world , and none from south india .
to the best of our knowledge , the present study should be the first to highlight the prevalence and anatomical location of duodenal diverticula in south indians .
one hundred and twenty specimens of duodenum from 108 male and 12 female subjects , in the age group of 25 to 63 years , procured from the department of anatomy , thanjavur medical college , thanjavur , and department of anatomy , aarupadai veedu medical college , puducherry , were utilized for this study , between the years 2005 and 2010 .
the specimens of duodenum and pancreas en block were removed , serially numbered , and preserved in 10% formalin .
specimens with duodenal diverticula were identified and carefully dissected , and its anatomical location on the duodenal wall was studied .
of the 120 specimens , diverticula were found in five specimens , the prevalence being 4.2% , and were located on the medial wall , which is morphologically the mesenteric border of the duodenum .
they were solitary , globular - shaped , and extraluminal with the fundus of the diverticula posterior to the duodenum , partially buried in the pancreas .
of the five specimens with diverticula , three ( 60% ) were present in the second part and two ( 40% ) in the third part of the duodenum .  
diverticula in the second part of duodenum were located in the periampullary region , above the major duodenal papilla .
sizes of the diverticula in the second part ( figures 1 and 2 ) were 2.5 , 0.7 and 0.5  cm and in the third part ( figure 3 ) 3  cm and 0.5  cm .
duodenal diverticula can be classified into intraluminal duodenal diverticulum ( idd ) and extraluminal duodenal diverticulum ( edd ) .
idd are congenital , resulting from defective recanalisation of duodenal lumen during fetal development   with coexistent congenital anomalies .
edd are acquired or false diverticula , resulting from mucosal herniation at the point where blood vessels penetrate the intestinal wall , which also explains their typical location at the medial or pancreatic border , in 88% of cases .
only 4% of them occur on the lateral wall of the duodenum . in the present study also , the diverticula were extraluminal and found on the medial wall , which is morphologically the mesenteric border of the duodenum .  
even though some studies state that there is no gender predisposition [ 4 , 5 , 13 ] , grant boileau   came across two diverticula in 11 female subjects as compared to 13 from 122 male subjects . in case 's   series of 85 cases of duodenal diverticula , 60% occurred in females .
mackenzie et al .   have also reported a female preponderance in the ratio from 1.6 to 1 . however , in the present study , diverticula were found only in the male subjects , and the absence of the diverticula in female subjects could be due to less study population , which was also one of the limitations of our study .  
review of the literature demonstrates that the incidence of duodenal diverticulum is highly variable according to the diagnostic procedure used .
the incidence in upper barium series is 0.16 to 6% and in ercp studies 0923% [ 57 ] .
a study in mexico by acua et al .   reported an incidence up to 11.6% by endoscopic cholangiography .
in autopsy series by akhrass et al . , an incidence of 0622% has been reported . in a study done in 105 specimens , 14 cases ( 13% ) of duodenal diverticula with 13 solitary and one multiple
of the 133 cadavers examined by grant boileau , diverticula were found in 15 subjects ( 11.2% ) , with 11 solitary and four multiple . among them , 12 were globular in shape , three were conical , and five were tubular .
ackermann , in an anatomical study of 50 cadavers , reported an incidence of 22% , with eight solitary and three multiple diverticula .
the highest on record to the present date is 31.8% , in a cadaveric study by minoru and atsuyoshi .
thus , incidence of duodenal diverticula from various cadaveric studies is certainly higher than the incidence from any other diagnostic procedure , in view of the fact that the search for diverticula is more accurate in cadavers than visualizing them in any other methods of investigations .
however , the present study revealed a lower prevalence of 4.2% when compared to that in the literature ( table 1 ) .  
most of the duodenal diverticula occur in the periampullary region of the duodenum , within 2.0  cm of the ampulla of vater [ 17 , 20 , 21 ] .
several studies confirmed that the second part is the most common site followed by the third and fourth part of the duodenum . in a study by lapin et al .
, 62% of duodenal diverticula occurred in the second part , followed by the third ( 30% ) and fourth part ( 08% ) .
, in their study , showed that 82% of duodenal diverticula occurred in second part , 10% in the third , and 08% in the fourth part . in the present study as well , three diverticula ( 60% ) were found in the second part , in the periampullary region , above the major duodenal papilla , and two ( 40% ) in the third part of the duodenum , of the total five diverticula .
distribution of duodenal diverticula in various parts in duodenum is shown in table 2 .   despite the fact that duodenal diverticula are asymptomatic in 90% of cases , the higher frequency in the second and third part
is associated with increased incidence of biliary stones , pancreatitis , and biliary and pancreatic anomalies .
concurrently , size of the diverticula is also of clinical importance since jaundice , cholangitis , and obstruction of pancreatic duct or bile duct have been reported due to the pressure effects . in case 's radiological study of 85 cases ,
the average size of the diverticulum was 2.8  cm . in the present study ,
the size of the diverticula was 0.5 to 3  cm ( mean : 1.4  cm ) , as compared to the mean value of 1.7  cm ( range : 0.4  cm to 4.5  cm ) by wiesner et al .
however , the dimensions of the diverticula in cadavers may be smaller than in life because of shrinkage during the embalming process , which is a disadvantage in our study .  
since less than 10% of patients develop nonspecific clinical symptoms like abdominal pain or discomfort , diagnosis of duodenal diverticula is incidental , found only during other diagnostic or therapeutic procedures .
however , 6.5% of patients may develop complications . in the most common complications , being hemorrhage and pancreaticobiliary diseases
, the clinical presentation may mimic acute cholecystitis , acute pancreatitis , or peptic ulcer disease [ 3 , 7 , 28 ] . even though complications of diverticula are recognized with the advent of ct ,
misdiagnosis is still problematic , as it is not commonly considered in differential diagnosis and due to the fact that its asymptomatic presentation masks the true incidence of duodenal diverticula .  
however , in the present study we found that the prevalence of duodenal diverticula is lower in south indians , when compared to other studies . a vegetarian diet and high intake of fiber could be significantly associated with lower risk of diverticular diseases   for they were correlated with rapid bowel transit times [ 31 , 32 ] , thus reducing the intraluminal pressure .
small bowel diverticula , in fact can be found in patients older than 50 years with peristaltic disorders , such as progressive systemic sclerosis , visceral myopathy , and visceral neuropathies leading to an increase in intraluminal pressure .
thus , a low fiber diet and advancing age might contribute to the risk of developing acquired duodenal diverticula .
the low prevalence rate of duodenal diverticula in south indians could be attributed to the indian diet , which consists of rice , wheat , ragi , lentils , vegetables , yoghurt , and less animal protein .
duodenal diverticula being asymptomatic in 90% of cases makes it difficult to ascertain the incidence and constitutes a diagnostic and therapeutic challenge due to their non - specific presentation .
thus , awareness of the frequency and location of duodenal diverticula is of great importance in the diagnosis and management of pancreaticobiliary diseases . in conclusion ,
our report serves to highlight the prevalence and anatomical location of duodenal diverticula in south indians .
the present study revealed a lower prevalence ( 4.2% ) of duodenal diverticula comparable to that in the literature , and whether this could be attributed to the indian diet pattern needs further study .
background . 
 duodenum is the second most common site of diverticula after the colon . 
 diagnosis of duodenal diverticula is incidental and found during other therapeutic procedures . in 90% of cases 
 , they are asymptomatic , and less than 10% develop clinical symptoms . 
 the difficulty to ascertain the true incidence of duodenal diverticula demanded for the present study to elucidate the prevalence of the duodenal diverticulum in south indians . 
 materials and methods . 
 one hundred and twenty specimens of duodenum were utilized for the study . the prevalence , anatomical location , and dimension of duodenal diverticulum were studied . results . among the 120 specimens of duodenum , five specimens had solitary , extraluminal , and globular - shaped diverticula in the medial wall of the duodenum . in three ( 60% ) cases , 
 it was found in the second part of duodenum and in two ( 40% ) cases in the third part . 
 the mean size of the diverticula was 1.4  cm . conclusion . in the present study in south indian people , the prevalence ( 4.2% ) of duodenal diverticula is low comparable to other studies in the literature 
 . even though most of the duodenal diverticula are asymptomatic , the knowledge about its frequency and location is of great importance to prevent complications like diverticulitis , hemorrhage , obstructive jaundice , and perforation .