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Abstract
A young man in his early 30s presented to our hospital with upper abdominal pain radiating to the back, progressive jaundice with pruritus, low-grade fever, vomiting and significant weight loss over 4 months. The syndrome of extrahepatic biliary obstruction was considered. There was no significant past, personal or family history. Imaging was suggestive of mucinous cystic lesions of the pancreas with significant lymphadenopathy. He was initially planned for surgery. However, endoscopic ultrasound-guided fine-needle aspiration from the lesion tested positive for tuberculosis and he improved dramatically with antituberculosis therapy. When a patient has an atypical presentation, tuberculosis should always be considered, especially if they reside in a tuberculosis-endemic country.
- Tuberculosis
- Pancreas and biliary tract
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Background
Tuberculosis remains a significant global health issue even in the 21st century. In 2022, an estimated 10.6 million people worldwide were diagnosed with tuberculosis, translating to 133 new cases per 100 000 individuals.1 Dubbed ‘the great masquerader’, tuberculosis can mimic other diseases, complicating its diagnosis and treatment. Pancreatic tuberculosis can present in various ways, including obstructive jaundice, mass-mimicking pancreatic malignancy, acute or chronic pancreatitis, abscess or gastrointestinal bleed. However, isolated pancreatic tuberculosis presenting as a cystic lesion of the pancreas is relatively uncommon. Here, we report a young patient with imaging suggestive of pancreatic cystic lesions. He was initially planned for surgery, but endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) done from the lesions changed the line of management.
Case presentation
A young man in his early 30s presented with progressively worsening upper abdominal pain for 4 months; the pain radiated to the back and was aggravated by food. There was progressive jaundice associated with pruritus, low-grade fever and vomiting. He had marked weight loss (20 kg in 4 months) and a loss of appetite. There was no significant personal or family history. He had no addictions.
He was evaluated elsewhere for the above complaints and was advised surgery. He presented to our hospital for a second opinion.
On examination, he appeared icteric; mild fullness and tenderness were noted in the epigastrium. He weighed 53.9 kg at the time of presentation.
Investigations
Haemoglobin was 147 g/L; total white blood cell count was 10 x 
/L (neutrophils: 6.3x
/L; lymphocytes: 2.4 x 
/L ; monocytes: 1.2 x 
/ L). Liver biochemistry revealed a cholestatic pattern with a total bilirubin of 94.9 µmol/L with a predominant direct fraction, alkaline phosphatase of 13 µkat/L and albumin of 40 g/L. Serum creatinine was 65.4 µmol/L; fasting serum triglyceride was 2.53 mmol/L; serum calcium was 2.5 mmol/L. He tested negative for HIV serology. His chest X-ray was unremarkable. Glycosylated haemoglobin was 64 mmol/mol. Carbohydrate Antigen 19-9 (CA 19–9) was 151 kIU/L. Serum IgG4 was 3.1 g/L (normal range: 0.03–2.01 g/L).
Contrast-enhanced CT (CECT) abdomen with magnetic resonance cholangiopancreatography (MRCP) (figure 1) showed peripherally enhancing multilocular cystic lesions with thickened internal septa involving the head, neck and tail of the pancreas and lymphadenopathy. After discussion in a multidisciplinary team meeting involving the gastroenterologist and the surgeon, it was planned to do an EUS with biopsy followed by surgery.
Contrast-enhanced CT abdomen with magnetic resonance cholangiopancreatography. (a) 5.3×5.2 cm multilocular cystic lesion in the pancreatic tail (denoted by the arrow) with thickened internal septa and few prominent vessels—probable postpancreatitis sequelae (walled-off necrosis)/tumour. (b) A multilocular cystic lesion (represented by the arrow) measuring 4.4×3 cm involving the head and neck of the pancreas with thickened internal septa and absent restricted diffusion on MRI, suggesting a cystic neoplasm of the pancreatic head. (c) Peripancreatic nodes (indicated by a white arrow). (d) Periportal nodes (shown by a black arrow). (e) A dilated common bile duct (up to 2 cm as shown by the measuring yellow line) with an abrupt cut-off in the pancreatic head region with moderate dilatation of central and peripheral biliary radicles.
EUS showed a multiloculated macrocystic lesion (largest cyst of diameter 3 cm) in the head of the pancreas (figure 2); some of the cystic areas appeared clear, and the other areas appeared solid, suggesting a mucinous neoplasm. In the tail of the pancreas, the parenchyma had a dirty heterogenous oedematous appearance, consistent with changes of acute pancreatitis; no cystic areas were made out.
Endoscopic ultrasound images. (a) A cystic lesion at the head of the pancreas (with the line across the lesion) and a dilated common bile duct. (b) A lesion at the tail of the pancreas (indicated by the arrow).
A 25-gauge needle was passed into the area that appeared solid in the lesion at the head of the pancreas, but only straw-coloured turbid fluid was aspirated. Fluid glucometer sugar was low.
The fluid aspirated was scanty and paucicellular. Cytospin smears showed many macrophages in clusters, along with many neutrophils forming aggregates and a few lymphocytes. Mucinous material [Periodic acid - Schiff - diastase (PASD)+] was seen and enmeshed within occasional clusters of multilayered and partly degenerate ductal epithelial cells displaying moderate anisokaryosis and moderate amounts of cytoplasm (mild atypia). There was no evidence of malignancy, high-grade epithelial atypia or necrosis. A neoplastic mucinous lesion could not be excluded because of the abundant thick colloid-like extracellular mucin and scanty epithelial clusters.
Pancreatic fluid analysis revealed elevated amylase (70 050 U/mL), CA 19–9 (1721 kIU/L) and low CarcinoEmbryonic Antigen (CEA) (0.30 µg/L). Pancreatic fluid Xpert TB PCR detected Mycobacterium tuberculosis, which was susceptible to rifampicin.
Differential diagnosis
Pancreatic cysts can be morphologically classified into unilocular cysts, microcystic lesions, macrocystic lesions and cysts with solid components. Macrocystic lesions (which are multilocular cysts with fewer, larger compartments, each over 2 cm) suggest mucinous cystic neoplasm (MCN), which includes mucinous cystadenoma, mucinous cystadenocarcinoma and intraductal papillary mucinous neoplasm (IPMN). Cysts with solid components may indicate MCN, IPMN, solid and papillary epithelial neoplasm (SPEN) or solid neoplasms showing cystic degeneration, such as adenocarcinoma and islet cell tumours.2
There was a diagnostic dilemma: the lesion in the tail of the pancreas could be walled off necrosis or tumour. The macrocystic lesion in the head of the pancreas could be MCN or IPMN. However, the male sex and the turbid fluid with low fluid CEA were against them. EUS-guided FNA showed no definite evidence of malignancy. The fluid Xpert TB PCR detected M. tuberculosis, whose significance was unclear.
As the diagnosis was uncertain if the lesions were neoplastic or of tuberculous aetiology, the case was reviewed in a multidisciplinary team meeting involving the surgeon, infectious disease specialist and gastroenterologist. It was decided to do biliary stenting, followed by a trial of antituberculosis treatment (ATT) to observe how the lesions would respond.
Other differential diagnoses that were considered were lymphoma and autoimmune pancreatitis. However, EUS cytology was not consistent with either of the two.
Treatment
He underwent endoscopic retrograde cholangiopancreatography (ERCP). Cholangiogram showed distal biliary stricture and dilated proximal common bile duct (17 mm) (figure 3). Sphincterotomy was done, and two 7 French 12 cm double pigtail plastic biliary stents were placed in the bile duct. Postbiliary stenting, his liver biochemistry started to improve, and he was initiated on weight-based ATT—isoniazid 300 mg, rifampicin 600 mg, ethambutol 1000 mg and pyrazinamide 1250 mg daily.
Endoscopic retrograde cholangiography showed dilated proximal common bile duct (pointed out by the arrow) and a narrowed distal common bile duct .
Outcome and follow-up
When he returned for a follow-up visit 8 weeks later, his abdominal pain had decreased in both severity and duration. He started to gain weight (53.9 → 56 kg). The patient had tolerated the antituberculosis drugs and was compliant as well. The mycobacteria culture and sensitivity test, automated Mycobacteria Growth Indicator Tube (MGIT AUTO) test performed on the cyst fluid obtained during EUS FNA was reported: M. tuberculosis was grown in culture and was susceptible to all the first-line antituberculosis drugs. Liver biochemistry had completely normalised (total bilirubin 8.38 µmol/L; alkaline phosphatase 1.85 µkat/L and albumin 49 g/L). Follow-up cross-sectional imaging (CECT abdomen with MRCP) (figure 4) showed complete resolution of the previously noted large lobulated cystic lesion near the tail of the pancreas. There was a significant reduction in the size of the lesion at the head of the pancreas and the lymph nodes.
Follow-up contrast-enhanced CT abdomen with magnetic resonance cholangiopancreatography after 8 weeks of antituberculosis therapy. (a and b) Residual lesions at the head of the pancreas (denoted by the arrows). (c) Resolved lesion at the tail of the pancreas.
He underwent ERCP, and the biliary stents were removed. There was a narrowing and granulation tissue at the D1–D2 junction. The cholangiogram showed no filling defects, and biliary balloon sweeps yielded no stone or sludge.
Mucosal biopsy from the D1–D2 junction showed moderate villous blunting and broadening, mild crypt elongation and mild cryptitis suggestive of moderate chronic duodenitis with mild activity. The lamina propria showed focal lymphangiectasia and focal histocytic aggregates. There was no necrosis or definite evidence of dysplasia or malignancy. Special stains for acid-fast bacilli and fungal organisms were negative. Although the possibility of tuberculosis could not be excluded based on histopathology, as M. tuberculosis was grown in MGIT culture, he was continued on ATT—isoniazid 300 mg, rifampicin 600 mg and ethambutol 1000 mg daily.
When he came for his next review visit after completing 9 months of ATT, he was doing well: pain-free and had gained weight (56.62 kg). Follow-up MRCP (figure 5) showed near complete resolution of the cystic lesion at the head of the pancreas and underlying chronic pancreatitis with a possibly benign biliary stricture.
Follow-up MRCP after 9 months of anti-tuberculosis therapy. (a) Near complete resolution of the cystic lesion seen previously in the head region. (b) A diffusely atrophic pancreas and dilated main pancreatic duct, measuring up to 5 mm (marked by the arrow). (c) Three-dimensional reconstruction of the MRCP images shows a stricture in the pancreatic duct in the body region with a dilated main pancreatic duct (pointed out by the blue arrow) suggestive of underlying chronic pancreatitis. The biliary radicles and proximal common bile duct appeared persistently dilated (11 mm) with smooth tapering at the infrapancreatic region (shown by the red arrow), likely benign stricture. MRCP, magnetic resonance cholangiopancreatography.
The final diagnosis was primary pancreatic tuberculosis (treated) and resolved sequelae of acute exacerbation with underlying early-onset idiopathic chronic pancreatitis and possibly benign biliary stricture.
Discussion
Pancreatic tuberculosis is more commonly observed in individuals in their fourth and fifth decades of life,3 with a higher incidence in males than females.4 5 It usually arises as a complication of miliary tuberculosis or immunodeficient states. Autopsy studies by Auerbach6 and Paraf7 reported incidences of pancreatic tuberculosis at 4.7% and 2.1%, respectively. Radiological studies have shown an incidence of 8.3%.5 Isolated pancreatic tuberculosis is rare, even in countries where tuberculosis is endemic. Pancreatic extracts exhibit antimycobacterial properties,8–11 accounting for their rarity.
Numerous theories have been proposed to explain M. tuberculosis infection of the pancreas: lymphatic and haematogenous spread following initial pulmonary exposure; direct extension from adjacent organs, including lymph nodes; reactivation of latent pancreatic tuberculosis triggered by alcohol, pancreatitis, drugs or surgical manipulation; a toxic-allergic reaction of the pancreas, reflecting a non-specific inflammatory response to mycobacterial antigens.12
Clinical features include abdominal pain, jaundice, fever, anorexia, weight loss and abdominal mass.13 CECT of the abdomen is the imaging modality of choice. Only a handful of case reports describe pancreatic tuberculosis presenting as cystic lesions.14–18
Pancreatic tuberculosis can be either focal or diffuse. Focal involvement occurs most commonly in the pancreatic head, followed by the body and tail, in descending order of frequency. Diffuse involvement of the pancreas is characterised by pancreatic enlargement with narrowing of the main pancreatic duct and is exceedingly rare.19
Pancreatic space-occupying lesions with predominant cystic components include pancreatic pseudocyst and cystic neoplasms (MCN, IPMN and SPEN), whereas those with predominant solid components include adenocarcinoma, lymphoma and metastases.20 Autoimmune pancreatitis can also mimic pancreatic tuberculosis.21 Precise diagnosis is crucial to prevent unnecessary surgery. EUS-guided FNA is the preferred diagnostic test for pancreatic masses.
If percutaneous or EUS-guided approaches fail to establish the diagnosis, surgical options such as laparoscopic biopsy or resection for suspected malignancy may be required.
Standard antituberculosis treatment is the cornerstone of therapy and typically includes a combination of medications administered for 6–12 months. Patients are assessed at 2 months and at the end of the treatment. As assessed by CECT, response to treatment is categorised as complete or partial (with at least a 50% reduction in the volume of involvement).22 If the disease progresses despite standard therapy, multidrug-resistant organisms or the coexistence of pancreatic malignancy should be suspected.
Patient’s perspective
I was initially frightened about having surgery, so I sought a second opinion. The doctors advised me to have an endoscopic procedure before the surgery. After reviewing the test results, they decided against surgery and suggested a course of medications instead. Although taking the tablets daily was challenging, it helped me avoid the surgery. I am thankful to the doctors for their timely decision.
Learning points
Tuberculosis should be considered in the differential diagnoses of pancreatic masses even in immunocompetent patients with no past or family history of tuberculosis, particularly if they are from a tuberculosis-endemic country.
Preoperative endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) of pancreatic lesions can prevent unnecessary surgeries, especially if the lesion is resectable but there is a diagnostic uncertainty.
Xpert TB PCR and Mycobacterial Growth Indicator Tube (MGIT) testing should be performed on EUS-FNA samples if the patient has an atypical clinical presentation: in this case, a macrocystic lesion in a male, fever and multiple lymph nodes on imaging.
Ethics statements
Patient consent for publication
Footnotes
Contributors The following authors were responsible for drafting of the text, sourcing and editing of clinical images, investigation results, drawing original diagrams and algorithms, and critical revision for important intellectual content: SPS, AP, HVK and AJJ. The following authors gave final approval of the manuscript: PSS, AP, HVK and AJJ.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.