Infection with Mycobacterium tuberculosis (TB) can cause a wide range of symptoms. Although miliary tuberculosis frequently involves the liver, spleen, colon, and mesenteric lymph nodes, tuberculosis that exclusively affects the peripancreatic lymph nodes is a rare clinical condition1. On imaging, it is frequently mistaken for cancer or pancreatitis. This might necessitate unnecessary surgery. It is crucial to diagnose this condition prior to surgery because it is a curable disease2. We present a case series of 3 suchpatients diagnosed with space-occupying lesion of the pancreas on imaging and found to have peripancreatic tuberculous lymphadenopathy on endoscopic ultrasound (EUS) examination.
Case Series
Clinical details of all three patients have been described in Table 1 (Case series of patients with peripancreatic tuberculous lymphadenopathy). Computed tomography (CT), EUS and histopathology findings of the three patients have been illustrated in Figures 1,2,3,4 respectively.
Discussion
Abdominal TB can present in an isolated nodal form as abdominal lymphadenopathy.1 The lymphatics of the ileocecal region, jejunum, ileum, and right side of the colon drain the ingested infectious material, which accounts for the common involvement of the mesenteric root, celiac, porta hepatis, and peripancreatic lymph nodes3. Retroperitoneal lymph nodes are largely unaffected, and their involvement rarely occurs alone4. There is widespread speculation that lymphohematogenous dissemination from an undetected focus in the lung is how tubercle bacilli spread to the peripancreatic lymph node1. Solitary or isolated tuberculous peripancreatic lymph node involvement is exceedingly rare. It might be associated with one of four possible clinical circumstances: the infection could cause gastrointestinal bleeding, pancreatitis, obstructive jaundice, or mimic a pancreatic neoplasm as a discrete mass. In this case series, all three patients presented with a pancreatic neoplasm on imaging and were found to have peripancreatic tuberculous lymphadenopathy on EUS examination.
On imaging, the lymph nodes are either distinct or appear as matted conglomerated masses. The CT characteristics of pancreatic tuberculosis are non-specific which include an irregularly shaped, hypodense, hypovascular mass with peripheral enhancement; areas of central enhancement that can give a multiloculated appearance with nearby necrotic or non-necrotic lymphadenopathy. These characteristics mimic those of pancreatic cystic lesions that are inflammatory or neoplastic5. A clearly defined mass that typically appears in the pancreatic head and exhibits heterogenous enhancement are MRI findings of focal pancreatic TB. On fat-suppressed T1-weighted images, these lesions are typically hypointense, and on T2-weighted images, they exhibit a mixture of hypo/hyperintensity2.
Biliary obstruction may develop as a result of external compression or direct ductal compression by infected nodes, along with periductal inflammation and stricture1. With a success rate ranging from 50 to 62%, fine needle aspiration cytology/biopsy has been used to diagnose a small number of patients2. High-resolution imaging with EUS enables the detection of abdominal and mediastinal lymphadenopathy as well as the differentiation of pancreatic and peripancreatic tumors. For diagnostic reasons, fine-needle biopsy (FNB) or EUS-guided fine-needle aspiration (FNA) can be used to investigate lymphadenopathy or pancreatic masses. It can detect pancreatic cancer up to 95% of the time and pancreatic tuberculosis up to 76% of the time6. Samples acquired could be sent for histology and microbiology utilizing acid-fast bacilli culture, Ziehl-Neelsen staining, and polymerase chain reaction assay2. According to reported literature, anti-tuberculous drug therapy is advised for 6-12 months5.
Endoscopic intervention is required in patients who develop obstructive jaundice due to biliary stricture, which may be progressive despite initiation of anti-tuberculous therapy. This intervention should be carried out early on in the course of treatment5. The progression or resolution of the disease can be guided by CT imaging6. In this case series, one patient needed biliary intervention, and all three patients showed clinical and biochemical response to anti-tuberculous therapy on follow up.
Conclusion
Large peripancreatic lymphnodes compressing the pancreas and surrounding adjacent vasculature can mimic pancreatic masses and may be mistaken for malignancy.In endemic nations, tuberculosis should be considered, especially in young patients in whom pancreatic mass is reported on imaging.
References
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- Chatterjee S, Schmid ML, Anderson K, Oppong KW. Tuberculosis and the Pancreas: A Diagnostic Challenge Solved by Endoscopic Ultrasound. A Case Series. J Gastrointestin Liver Dis. 2012;21(1):105–7.
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