Indian Journal of Pathology and Microbiology

IMAGES
Year
: 2012  |  Volume : 55  |  Issue : 3  |  Page : 413--414

Inflammatory pseudotumor of the biliary tract


R Subhash1, ML Arunkumar1, Bonny Natesh1, Laila Raji2,  
1 Department of Surgical Gastroenterology, Government Medical College, Thiruvananthapuram, Kerala, India
2 Department of Pathology, Government Medical College, Thiruvananthapuram, Kerala, India

Correspondence Address:
R Subhash
Department of Surgical Gastroenterology, Government Medical College Thiruvananthapuram, Thiruvananthapuram, Kerala - 695 011
India




How to cite this article:
Subhash R, Arunkumar M L, Natesh B, Raji L. Inflammatory pseudotumor of the biliary tract.Indian J Pathol Microbiol 2012;55:413-414


How to cite this URL:
Subhash R, Arunkumar M L, Natesh B, Raji L. Inflammatory pseudotumor of the biliary tract. Indian J Pathol Microbiol [serial online] 2012 [cited 2020 Aug 13 ];55:413-414
Available from: http://www.ijpmonline.org/text.asp?2012/55/3/413/101763


Full Text

Inflammatory pseudotumor (IPT) of the biliary tract is a rare benign disease. [1] The clinical manifestations and imaging features of this lesion are similar to malignant neoplasms of the biliary tree. Here we discuss such a case of IPT of the biliary tract which clinically resembled hilar cholangiocarcinoma.

A 21-year-old female presented with painless progressive jaundice of 1-month duration. She had generalized pruritus, severe loss of weight, and loss of appetite. On examination she had icterus and hepatomegaly. Laboratory investigations revealed evidence of obstructive jaundice with serum total bilirubin 273.6 μmol/l, conjugated bilirubin 140.2 μmol/l and serum alkaline phosphatase 789 U/L. Serum tumor marker assays showed a Carbohydrate antigen 19-9 level of 45 U/ml, Alpha-fetoprotein of 4 ng/ml and Carcinoembryonic antigen of 1.4 ng/ml. Hepatitis serology and HIV status were negative. Ultrasonogram showed a collapsed gallbladder with bilateral intrahepatic biliary radicle dilatation and a suspicious lesion at the hilum of the liver. Subsequent magnetic resonance imaging (MRI) [[Figure 1]a and b] revealed a definite lesion at the confluence of the right and left major bile ducts with extension into the left duct involving secondary biliary radicles on that side, consistent with Type-3b Klatskin tumor according to Bismuth classification. The lesion was hypointense in T2, FIESTA, and LAVA sequences of MRI and it showed a moderate enhancement in the venous phase. After preoperative optimization, the patient was taken up for surgery with the diagnosis of hilar cholangiocarcinoma. Intraoperatively, a lesion was seen at the hilum of the liver with extension into left lobe. So an en-bloc excision of the tumor with left hepatectomy, caudate lobe excision, and excision of extrahepatic biliary tree was done. On cutting through the hilum, an ill-circumscribed gray-white firm to hard area was identified grossly [[Figure 2]a-c] involving the confluence of right and left bile ducts with extension of the lesion into the left liver. The rest of the liver showed dilated biliary radicles. The gall bladder wall was thickened and the lumen was filled with solidified brownish mucoid material. Microscopically [[Figure 3]a and b] the lesion was composed of fascicles of spindle cells including fibroblasts and myofibroblasts infiltrated by plasma cells and lymphocytes. On Immunohistochemistry [Figure 4], myofibroblasts tested positive for smooth muscle actin and were negative for cytokeratin and S100. Thus histopathology gave a surprising diagnosis of inflammatory pseudotumor or inflammatory myofibroblastic tumor of the biliary confluence.{Figure 1}{Figure 2}{Figure 3}{Figure 4}

IPT is an idiopathic benign mass lesion composed of fibrous tissues and myofibroblasts with marked inflammatory infiltration by plasma cells and lymphocytes. [1] The most common sites of involvement are the lungs, mesentery, and omentum. Other sites such as soft tissues, mediastinum, gastrointestinal tract, pancreas, genitourinary system, oral cavity, skin, breast, nerve, bone, and salivary glands may also be involved. [1] IPT involving biliary tract is rare. It usually occurs in children and young adults. The clinical and imaging features of this lesion are similar to that of a neoplasm, and the biological behavior and the property of spontaneous regression suggest a benign nature. [2] There are several reports of its association with antecedent infections and so some consider IPT as a non-specific chronic inflammatory lesion. Epstein-Barr virus has been found within the lesion in some IPTs, particularly in the liver. [3] This lesion is also associated with mutations resulting in over expression of Anaplastic Lymphoma Kinase 1 gene. Clinically IPT presents with progressive obstructive jaundice, abdominal pain, fever, anemia, and features which make it indistinguishable from biliary tract malignancy. [4] Tumor markers like CA 19-9 may be elevated in both malignancy and IPT. Imaging appearance also may be deceptive as it presents with mass lesions, biliary radicle dilatations, infiltrations and even delayed and persistent enhancement with contrast; features which are strikingly similar to cholangiocarcinoma. [2] Disease presenting with obstructive features requires surgical treatment. But so far, there is no investigative modality available to rule out malignancy and to decide on the extent of resection. Intraoperative frozen section biopsy may be of some help in this regard, though technical issues and sampling errors do occur.

References

1Coffin CM, Watterson J, Priest JR, Dehner LP. Extrapulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). A clinicopathologic and immunohistochemical study of 84 cases. Am J Surg Pathol 1995;19:859-72.
2Tublin ME, Moser AJ, Marsh JW, Gamblin TC. Biliary inflammatory pseudotumor: Imaging features in seven patients. AJR Am J Roentgenol 2007;188:W44-8.
3Arber DA, Weiss LM, Chang KL. Detection of Epstein-Barr virus in inflammatory pseudotumor. Semin Diagn Pathol 1998;15:155-60.
4Gohy S, Hubert C, Deprez P, Van Beers BE, Annet L, Lhommel R, et al. Benign biliary inflammatory pseudotumor mimicking a Klatskin tumor. Hepatogastroenterology 2007;54:1348-52.