Annular pancreas is an uncommon condition in adults. The ring formation generally originates from the failure of normal clockwise rotation of ventral pancreas. First described by Tiedmann in 1818, its incidence is 1:20,000 population. It has bimodal presentation i.e is seen either in Infants or in 4th & 5th decade of life.

1. ANNULAR PA
NCREAS: AN UNUSUAL PRESENTATION

2. Case Report
Nitish Anchal*, Prithpal Singh**, Saket Goel***, Sanjay Sikka@, Deep Shikha Arora@@
*Junior Consultant, Department of Surgery,**Fellow, Department of Surgical Gastroenterology, ***Senior Consultant,
Department of Surgical Gastroenterology, @Senior Consultant, Department of Gastroenterology, Senior Consultant,
Department of Histopathology, Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi 110 076.
Correspondence to: Dr. Deepak Govil, Senior Consultant, Department of Histopathology, Indraprastha Apollo Hospitals,
CASE REPORT
ANNULAR PANCREAS: AN UNUSUAL PRESENTATION
and Deepak Govil***
Sarita Vihar, New Delhi 110 076.
A forty three years male presented with a moderate
intensity pain in the epigastric region, radiating to back for
one week. He also complained of non bilious vomiting
containing undigested food particles. He had lost about 7 kg
weight in last 5 months. He had an episode of pain
diagnosed as acute pancreatitis 6 months back on the basis
of raised serum amylase and lipase levels. He was treated
conservatively that time. He was neither an alcoholic nor a
smoker. On examination patient was afebrile, anicteric with
a pulse rate of 74 per min and blood pressure of 110/70 mm
Hg. Abdominal examination revealed non tender, epigastric
fullness, with succusion splash in the epigastrium. Routine
blood investigations showed Hb - 13.1 gm/dL, TLC -
11,600/cu mm and platelet count - 1,97,000/cu mm. His
liver function showed raised serum alkaline phosphatase -
310 IU (n <117 IU) and serum gamma glutamide trans
peptidase (GGTP) - 104 (n <50 IU). Serum amylase was
371 (30-110IU/L) and Serum lipase was 810 (23-300 U/L).
His CA 19.9 was marginally raised to 77 U/mL (0-35U/mL).
Contrast enhanced computerised tomography (CECT)
whole abdomen showed abnormally placed subhepatic
gallbladder with enlarged pancreatic head (4 × 3 cm) and
dilated main pancreatic duct (4 mm). No pancreatic
calcification was seen (Fig 1). CT also showed evidence of
biliary and duodenal obstruction with gastric distension.
Duodenal obstruction was also confirmed by upper
gastrointestinal endoscopy showing grossly distended
stomach with food residue. The scope could not be
negotiated beyond second part of duodenum.
On the basis of above findings and investigations we
made a working diagnosis of a pancreatic mass (? chronic
pancreatitis,?? carcinoma pancreas) with gastric outlet
obstruction, biliary obstruction and pancreatic duct
obstruction. Patient was planned for a resection procedure
and accordingly preoperative preparation and counseling of
the patient was done. He was operated on 2nd Dec’ 2009. At
operation we found that the gall bladder fundus was
adherent to the posterior peritoneal fold (Fig 2). There was
a hard pancreatic head mass measuring about 4×5cm,
along with a grossly distended and dilated CBD. Liver
appeared normal. We performed a Whipple’s pancreato-duodenec-
tomy with a feeding jejunostomy. The
pancreatic duct was also dilated (5 mm) and we did a duct
to mucosa pancreato- jejunostomy. Postoperatively
feeding was started through jejunostomy tube on second
postoperative day and on 5th postoperative day oral feeds
were started. Patient had a smooth postoperative recovery
and was discharged on ninth postoperative day.
Histopathology of surgical specimen showed second part
of duodenum was narrow and surrounded by pancreatic
tissue all around. Histopathological diagnosis was annular
pancreas with chronic pancreatitis with chronic
cholecystitis and reactive peripancreatic lymphnodes.
We retrospectively reviewed the preoperative CECT of
the patient, it was done from a local hospital and still did
not show evidence of annular pancreas.
REVIEW OF LITERATURE
Annular pancreas is an uncommon condition in adults.
The ring formation generally originates from the failure of
normal clockwise rotation of ventral pancreas. First
described by Tiedmann in 1818 [1], its incidence is
1:20,000 population. It has bimodal presentation i.e is seen
either in Infants or in 4th & 5th decade of life [2].
Embryonic development of pancreas and
biliary tree
The ventral pancreatic bud and biliary system arise
from the hepatic diverticulum, and the dorsal pancreatic
bud arises from the dorsal mesogastrium. After clockwise
rotation of the ventral bud around the caudal part of the
foregut, there is fusion of the dorsal pancreas (located
anterior) and ventral pancreas (located posterior). Finally,
307 Apollo Medicine, Vol. 7, No. 4, December 2010

3. Case Report
Fig 1 CECT whole abdomen
Fig 2 Intraoperative findings of the case.
the ventral and dorsal pancreatic ducts fuse, and the
pancreas is predominantly drained through the ventral
duct, which joins the common bile duct (CBD) at the level
of the major papilla. The dorsal duct empties at the level of
the minor papilla.
There are two theory postulated for development of
annular pancreas. Lecco [3] postulated that adhesion of the
distal tip of the ventral primordium to the duodenal wall,
before its migration, is responsible for the pancreatic
obstructing ring. Baldwin [4] stated that persistence and
further development of the left ventral bud is responsible
for the formation of the annular pancreatic tissue around
the duodenum. Abdominal pain was the most frequent
symptom, followed by vomiting and jaundice. The
symptoms of the disease in adults are often associated with
Apollo Medicine, Vol. 7, No. 4, December 2010 308

4. Case Report
pancreatic or gastric outlet obstruction. Division or
resection of the pancreatic annulus have high morbidity
and mortality rate [6]. Bypass surgery of the annulus in the
form of gastrojejunostomy, duodenojejunostomy or
pancreatico-duodenectomy. Annular Pancreas was found
concomitantly with ampullary carcinoma (5 cases) and
pancreatic adenocarcinoma (3 cases). The differential
diagnosis between focal inflammatory lesions in the head of
the pancreas due to chronic pancreatitis and pancreatic
cancer remains a challenging task for radiologists,
pathologists and surgeons. The association of annular
pancreas and periampullary malignancy in adults must not
be overlooked, and their coexistence must be considered
until its absence is proved. Annular pancreas can be a rare
cause of gastric, biliary and pancreatic duct obstruction. It
may be associated with recurrent pancreatitis. Resection is
advisable if there is suspicion of malignancy.
REFERENCES
1. Tiedmann Fuber die verschiedenheiten des
ausfuhrangsganges der bauchspeicheldruse bei
denmenschen und saugetieren. Dtsch Arch Physiol
1818; 4: 403.
2. Kiernan PD, ReMine SG, Kiernan PC, ReMine WH.
Annular pancreas - Mayo Clinic experience from 1957to
1976 with a review of the literature. Arch Surg 1980; 115:
46-50.
3. Lecco TM. Zur Morphologie des pankreas
annulare.Sitzungb Akad Wissensch 1910; 119: 391-406.
4. Baldwin WM. A specimen of annular pancreas. Anat Sec
1910; 4: 299-304.
5. Dharmsathaphorn K, Burrell M, Dobbins J. Diagnosis of
annular pancreas with endoscopic retrograde
cholangiopancreatography. Gastroenterology 1979;
77:1109-1114.
6. Michael C Beachley, Charles A Lankau. Symptomatic
adult annular pancreas. Digestive Diseases and
Sciences. 1973; 18(6), 513-516.
complications of peptic ulcer, pancreatitis, duodenal
obstruction and biliary tract obstruction. Although annular
pancreas may encircle the duodenum completely in adults,
the food usually can pass through the duodenum without
problem. But, annular pancreas may compress and obstruct
the duodenum secondary to chronic pancreatitis.
In our cases, patient presented with gastric outlet
obstruction and pancreatitis with raised serum amylase and
lipase levels. His CA 19.9 was marginally raised. On
endoscopy scope couldn’t be negotiated beyond second
part of duodenum.
The preoperative diagnosis of annular pancreas is often
difficult. Imaging is of paramount importance to establish a
correct diagnosis and to minimize surgical intervention.
Upper GI series have been considered the study of choice.
CT scan illustrate the pancreatic tissue, completely or
partly encircling the duodenum. Crocodile jaw
configuration of pancreatic tissue is typical for annular
pancreas. Presence of pancreatic tissue posterolateral to
2nd part duodenum has sensitivity 92% and specificity
100%. Endoscopic ultrasonography and MRCP are useful
tools for diagnosis of Annular Pancreas.
ERCP is invasive, and its indication is limited in patients
with acute pancreatitis because it may aggravate the
situation or induce iatrogenic pancreatitis in normal
patients. Once duodenal obstruction is present, ERCP may
be technically difficult or impossible [5]. MRCP is a non-invasive
method for visualizing the biliary tree and
pancreatic duct without injection of contrast medium.
When the aberrant pancreatic duct encircling and
extending to the right side of the duodenum is identified by
MRCP, the diagnosis of annular pancreas is established.
But, sometimes the pancreatic duct without dilation is
invisible on MRCP.
Surgery is still necessary to confirm the diagnosis. The
main goal of surgical treatment is relief of duodenal,
309 Apollo Medicine, Vol. 7, No. 4, December 2010

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