Pancreatic tuberculosis mimicking pancreatic carcinoma: series of three cases

Ultrasound imaging features of isolated pancreatic tuberculosis

BACKGROUND AND OBJECTIVES

Isolated pancreatic tuberculosis (PTB) is extremely rare worldwide. The purpose of this multicenter retrospective study is to analyze imaging features of histologically confirmed isolated PTB in order to determine the diagnostic features of the new methods contrast enhanced ultrasound (CEUS), ultrasound elastography and contrast enhanced endoscopic ultrasound (CE-EUS).

PATIENTS AND METHODS:

We report on a retrospective data collection of 12 cases of PTB confirmed by histology or cytology. All examinations were interpreted by two independent readers in consensus. CEUS, CE-EUS and ultrasound elastography were performed according to the European Federation of Societies for Ultrasound in Medicine and Biology guidelines.

RESULTS:

In PTB patients the common bile duct was never dilated. Multiple retroperitoneal lymph nodes are the second important B-mode ultrasound feature detected in 75% of PTB patients. CE-EUS was performed in three PTB patients demonstrating hyperenhancement. On elastography, all PTB lesions were markedly stiffer than surrounding pancreatic parenchyma.

CONCLUSIONS:

Here we report the first time on CEUS and elastography features of PTB. PTB had some typical imaging features with iso- or hyperenhancement on CE(E) US. PTB is markedly stiffer on elastography. If clinicians are aware of clinical features of PTB and conduct appropriate investigations with multiple modalities including B-mode ultrasound, CEUS, and EUS guided fine needle aspiration, diagnosis of PTB without laparotomy is possible and the disease can be effectively treated with anti-tuberculous drugs.

[Pancreatic tuberculosis]

Prevalence, risk factors of primary pancreatic tuberculosis, clinical symptoms and data of instrumental and laboratory diagnosis are reviewed in the article. The authors emphasized the peculiarities of differential diagnosis with pancreatic malignancies and advisability of the most informative methods - endoscopy and fine-needle aspiration procedure.

Pancreatic tuberculosis

Pancreatic tuberculosis is very rare, but recently, there has been a spurt in the number of reports on pancreatic involvement by tuberculosis. It closely mimics pancreatic cancer, and before the advent of better imaging modalities it was often detected as a histological surprise in patients resected for a presumed pancreatic malignancy. The usual presentation involves abdominal pain, loss of appetite and weight, jaundice which can be associated with cholestasis, fever and night sweats, palpable abdominal lump, and peripheral lymphadenopathy. Computed tomography (CT) of the abdomen is an important tool for evaluation of patients with pancreatic tuberculosis. This CT imaging yields valuable information about the size and nature of tubercular lesions along with the presence of ascites and lymphadenopathy. However, there are no distinctive features on CT that distinguish it from pancreatic carcinoma. Endoscopic ultrasound provides high resolution images of the pancreatic lesions as well as an opportunity to sample these lesions for cytological confirmation. The presence of granulomas is the most common finding on histological/cytological examination with the presence of acid fast bacilli being observed only in minority of patients. As there are no randomized or comparative studies on treatment of pancreatic tuberculosis it is usually treated like other forms of tuberculosis. Excellent cure rates are reported with standard anti tubercular therapy given for 6-12 months.

Pancreatic tuberculosis: Evaluation of therapeutic response using F-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography

F-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG PET/CT) is a functional imaging technique that monitors glucose metabolism in tissues. Pulmonary tuberculosis (TB) has been reported to show intense uptake of FDG, with a decrease in metabolism of the tuberculous lesions after successful anti-tubercular treatment (ATT). The authors present a patient with pancreatic TB and demonstrate the usefulness of FDG PET/CT in monitoring the response to ATT.

Current status on the diagnosis and evaluation of pancreatic tumor in Asia with particular emphasis on the role of endoscopic ultrasound

In Asia, the incidence of pancreatic cancer in some countries has been increasing. Owing to most cases being diagnosed late, prognosis for pancreatic cancer remains dismal. It is clear that the future for pancreatic cancer lies in early detection. While the possible presence of pancreatic masses is often first raised by non-invasive abdominal imaging, such as computerized tomography and magnetic resonance imaging, smaller lesions and locoregional lymph node metastases are often not detectable by these means. Endoscopic ultrasonography (EUS) offers a higher sensitivity (93-100%) for detection of small potentially curable pancreatic masses than other existing imaging modalities. It is also recommended for the evaluation of portal vein confluence, portal vein, celiac axis, and superior mesentric artery origin, and exclusion of resectability. Due to the closer proximity of EUS to the target structure, and lower rate of needle tract seeding, EUS-guided fine-needle aspiration of pancreatic mass is considered the most suitable tissue acquisition technique. Lastly, EUS also enables the performance of endoscopic interventions. Its performance can be further enhanced with newer techniques, including contrast-enhanced ultrasound and elastrography. It is anticipated that in the near future, molecular technologies may make it possible to detect microscopic amounts of cancer in tissue or blood, predict relapse and survival after therapy, as well as determine optimal therapy.