the gastrointestinal tract is the most common site of extranodal non - hodgkin 's lymphoma ( nhl ) and the small bowel is considered the most commonly affected part of the gastrointestinal tract .
lymphoma of the hepatobiliary system usually presents as secondary manifestation of systemic malignant lymphoma . however , primary malignant lymphomas arising from the hepatobiliary tree are extremely rare .
a 71-year - old male patient with history of inflammatory bowel disease presented with progressive jaundice . on physical examination ,
laboratory evaluation confirmed cholestasis with the following findings : total bilirubin 86.6 mol / l ( normal : < 26
mol / l ) , direct bilirubin 66 mol / l ( normal < 7 mol / l ) , aspartate aminotransferase ( ast ) 95 u / l ( normal : 035
u / l ) , alanine aminotransferase ( alt ) 77 u / l ( normal : 336
u / l ) , and alkaline phosphatase 438 u / l ( normal : 35100
the cancer antigen 19 - 9 ( ca 19 - 9 ) was elevated with a value of 215 u / ml ( normal : < 37 u / ml ) . serologic markers of hepatitis b and c were negative .
mrcp and contrast - enhanced magnetic resonance imaging ( mri ) showed dilatation of the intrahepatic and extrahepatic bile ducts down to tight stenosis at the middle part of the common bile duct , measuring 2.3 cm and located almost 3.6 cm from the bifurcation of the common hepatic duct . at the area of stricture
, there was circumferential mural thickening with intermediate signal intensity in t1- and t2-weighted images and homogeneous post - contrast enhancement [ figures 1 and 2 ] .
( a ) magnetic resonance cholangiopancreatography ( mrcp ) coronal projection demonstrate 2.3 cm tight stricture at the mid - cbd ( white arrows ) with severe upstream dilatation .
( b and c ) non - contrast mri upper abdomen axial t1- and t2-weighted images show circumferential mural thickening at the area of maximum stenosis with intermediate signal intensity ( black arrows ) .
contrast - enhanced mri with axial post - contrast t1-weighted images at different levels : ( a ) at the level of the hepatic duct bifurcation , shows severe bilobar intrahepatic biliary dilatation ( short white arrows ) ; ( b ) at the level of the junction of the markedly dilated proximal cbd ( curved white arrow ) and the stenotic segment ( straight white arrow ) ; ( c ) at the level of mid - cbd stricture show that the lesion enhances homogeneously ( white arrow ) ; ( d ) at the level of distal cbd shows the normal caliber of the cbd within the pancreatic head ( black arrow ) .
no further diagnostic studies were arranged as the radiological , clinical , and laboratory features were indicative of cholangiocarcinoma .
the surgical plan was to perform whipple 's operation and the head of the pancreas , duodenum , common bile duct ( cbd ) , and gallbladder were resected .
gross examination showed a firm mass measuring 2.2  2  1.4 cm surrounding the duct and the cut surface showed grayish - white , lobulated tissue markedly compressing the distal cbd and showed a slit - like opening .
histopathologically , the mass was found to consist of lymphoid cell nodules surrounding and constricting the cbd .
these nodules were composed of small cleaved lymphocytes ( centrocytes ) and larger lymphoid cells ( centroblasts ) .
the centroblasts counted more than 16 cells per high - power field [ figure 3a and b ] .
histological sections stained with hematoxylin and eosin ( h and e ) ( a ) low - power view , ( 25 ) shows nodules of lymphoid cells ( white arrows ) surrounding the common bile duct ( dotted white arrows ) . ( b ) medium - power view , ( 200 )
immunochemical tests ( c ) shows the neoplastic lymphoid cells are positive for cd20 marker and ( d ) the cells are positive for cd10 marker .
immunohistochemical staining showed the neoplastic cells were positive for cluster of differentiation 20 ( cd20 ) , cluster of differentiation 10 ( cd10 ) , and b cell lymphoma 6 ( bcl6 ) markers [ figure 3c and d ] .
they were negative for cd3 , cd5 , b cell lymphoma 2 ( bcl2 ) , and multiple myeloma oncogene 1 ( mum1 ) .
ki-67 ( named after the location where it was discovered ; kiel university ) was expressed by 70% of cells within the follicles and 10% outside the follicles .
reviewing the english language medical literature on primary nhl originating from the bile duct , only 30 cases were found and most of them presented with jaundice and the most common subtype among these cases was diffuse large b - cell lymphoma ( dlbcl ) .
there is increasing incidence of nhl , which may be primarily due to a variety of factors , particularly the rising incidence of human immunodeficiency virus ( hiv ) infection .
follicular lymphoma of the gastrointestinal tract is extremely rare , accounting for only 1% of all gastrointestinal nhls . among those cases reviewed by lee et al .
, three cases were follicular lymphoma , of which two were males aged 33 and 32 years and one was a female aged 53 years , with all of them having the lymphomatous infiltration affecting the bifurcation of the cbd with gross soft tissue masses [ table 1 ] . while in our case , the lymphoma involved the middle part of the of the cbd without sizable soft tissue mass and was mainly seen as stenotic area . reported cases of primary follicular lymphoma of the common bile duct follicular lymphoma is considered to be an indolent lymphoma , but the clinical behavior of this lymphoma depends on the histologic grade and the extent of disease at presentation . with time ,
accurate pre - surgical diagnosis may alter the treatment choice , and chemotherapy should be the first choice for primary biliary lymphoma .
surgery should play a role if an accurate preoperative diagnosis can not be made , and the involved lesions produce complications , such as bile duct stricture , that are not amenable to non - surgical therapies .
also , failure of chemotherapy to eradicate localized disease is another situation where surgery may have a role . on the other hand
, radiotherapy should be reserved for residual disease after primary chemotherapy , or to relieve symptoms of pain caused by the disease .
correct pre - surgical diagnosis is quite difficult , but smooth surface of the stricture segment of the biliary tree seen by endoscopic retrograde cholangiopancreatography ( ercp ) or percutaneous transhepatic cholangiography ( ptc ) may indicate the extramural nature of the mass , and thus be suggestive of lymphoma .
homogenous intensity in both pre- and post - contrast study at the stenotic site of bile duct is another suggestive feature of lymphoma .
primary nhl is one of the rare differential diagnoses of cholangiocarcinoma and shows similar imaging findings . the clinical symptoms and signs , and the laboratory study are non - specific and sometimes misleading .
pre - surgical diagnosis is quite challenging due to non - specific clinical manifestations , laboratory profile , and imaging findings . if an accurate diagnosis is made before surgical intervention , chemotherapy is the first choice of treatment .
surgical resection should be reserved for those cases without a definite diagnosis , or for patients with complicating biliary obstruction , or who fail to respond to chemotherapy .
 primary non - hodgkin 's lymphoma of the common bile duct is extremely rare . 
 we present a case with history of inflammatory bowel disease and clinical manifestations of obstructive jaundice . 
 abdominal magnetic resonance imaging with magnetic resonance cholangiopancreatography ( mrcp ) was done and demonstrated tight stricture at the middle part of common bile duct , and radiological findings were supportive of extra - hepatic cholangiocarcinoma . 
 whipple 's procedure was performed and the case was histopathologically proven to be non - hodgkin 's lymphoma of follicular subtype involving the common bile duct . 
 lymphoma of the hepatobiliary system is usually present as secondary manifestation of systemic malignant lymphoma . 
 however , primary malignant lymphomas arising from the hepatobiliary tree are extremely rare . 
 the radiological appearance of common bile duct lymphoma is very similar to cholangiocarcinoma , making preoperative diagnosis very difficult , as in our present case . 
 we also compare the imaging findings of our case to those seen in reported cases of follicular lymphoma of the common bile duct . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONCLUSION