Tuberculosis biliary stricture simulating as cholangiocarcinoma.

Abstract

Tuberculosis (TB) is a rare cause of biliary stricture that is difficult to diagnose preoperatively. Patient present with obstructive jaundice, which may be confused with hepatobiliary malignancies. Suspicion of the disease with knowledge and awareness and establishing tissue diagnosis along with advent of image guided FNAC, endoscopic brush cytology and PCR testing of bile, diagnosis of hepatobiliary TB can be made without the need of laparotomy. Biliary TB is a potentially curable condition when diagnosed preoperatively requiring antituberculosis therapy & avoiding surgery [1]. Surgery is most often required for relief of biliary obstruction [2]. Failure to obtain preoperative tissue diagnosis may lead to histological diagnosis of biliary TB only after major surgery. TB of lower end of common bile duct (CBD) and periampullary region often forms pseudotumour and strictures mimicking cholangio carcinoma [3]. Hepatobiliary TB may be caused by three ways: (1) Spread of caseous material from the portal tracts into the bile ducts (most often), (2) Secondary inflammation-related tuberculous periportal lymphadenitis, (3) Spread of caseous material through the ampulla of Vater and ascending along the CBD [4]. Benign biliary strictures fall into two etiological groups: Traumatic (Post operative, Blunt, or Penetrating injury) and Nontraumatic (Sclerosing cholangitis, Recurrent pyogenic cholangitis, Chronic pancreatitis, Mirizzi syndrome) [5]. Various other benign conditions are Eosinophilic granuloma, Duodenal papillitis, Infestations due to Ascaris lumbricoides and Clonorchis sinensis. Tuberculous biliary stricture is due to the secondary endo luminal inflammatory process and scarring. Tuberculous biliary stricture involves all parts of the biliary tree, but commonly involving CBD [6]. We came across five cases of Tubercular biliary stricture in last six years. All the patients had no specific clinical findings & there was lack of constitutional symptoms of TB such as fever and night sweat, absence of past history of TB, negative tuberculin skin test, lack of radiological evidence of old or active TB. CBD was involved with either stricture or pseudo tumour [Table/Fig-1]. [Table/Fig-1]: Findings of five cases in present study The factors like (1) a past history of TB, (2) other systemic manifestations like pulmonary or generalized lymph node involvement, (3) associated involvement of other abdominal organs, (4) mild jaundice, (5) abdominal pain more than an abdominal mass, (6) image guided FNAC or biopsy in suspected cases, and (7) the geographic area where the patient resides might help in differentiating biliary TB from biliary tract malignancy [7]. Preoperative diagnosis of TB as the cause of obstructive jaundice is extremely difficult often compelling major resectional surgery such as whipples pancreatoduodenectomy. In most of the cases, final diagnosis is reached in the postoperative period by the histological finding of caseation necrosis and epitheloid granuloma formation and Langhans giant cells [1]. All the patients in our study were put on ATT. Patients without surgery showed improvement and are on regular follow up. My research review on various documented articles reflects the need to diagnose this disguising condition with various available investigations keeping TB in mind [Table/Fig-2]. [Table/Fig-2]: Comparison of various published literature with the present study There are several proposed investigations for preoperative diagnosis, for example, detection of acid fast bacilli (AFB) after staining or culture in the biliary fluid aspirate during ERCP, FNAC, and frozen section [18]. PCR technique for Mycobacterium TB from biliary fluid is helpful because of its sentivity [6]. The tubercular biliary stricture can be cured with antitubercular medications with excellent prognosis. In few reported cases, the biliary stricture does not resolve with medical therapy alone and requires surgical intervention and biliary metallic stent placement [1]. Whipples pancreastoduodenectomy is done for distal CBD stricture and choledochoduodenostomy is required in multiple strictures. Sequential placement of multiple plastic stents has been shown to be effective, as the stents both enable biliary drainage and act as dilators [17] . Although favourable results can be achieved by medical therapy and with repeated stenting of the bile ducts, long-term follow-up is required due to the risk of post-treatment cicatricial stenosis [5] . If preoperative diagnosis is established, major surgery can be avoided, which increases morbidity and mortality. Patients presenting with a short history with relatively good health from tuberculosis endemic country like India, tubercular biliary stricture should be kept in mind as a differential diagnosis. These benign lesions should be differentiated from malignant masquerade, equally keeping in mind not to mistake malignant lesions for benign lesions.