Pancreatic tuberculosis mimicking pancreatic malignancy with duodenal obstruction: a case report and review of the literature

Tuberculosis is a disease most people associate with the lungs, a condition that causes coughing and breathing difficulties. However, the bacteria that cause it can travel through the bloodstream to settle in almost any part of the body, including the liver, kidneys, and even the pancreas. When this happens in the pancreas, it creates a rare and tricky situation. The infection causes inflammation and forms lumps of tissue that look and behave very much like cancer on medical scans. Because the symptoms are vague and the images are deceptive, doctors often mistake this infection for a malignant tumor. This confusion can lead to major, life-altering surgeries that might not be necessary if the true nature of the illness were known earlier. Understanding how to tell the difference between a treatable infection and a deadly cancer is a critical challenge in modern medicine, especially when the patient's body is already under significant stress.

A team of researchers at The First Affiliated Hospital of Anhui Medical University recently documented a striking example of this diagnostic dilemma. They treated a 62-year-old man who arrived at the hospital suffering from two months of worsening abdominal bloating, nausea, and vomiting. He had lost a noticeable amount of weight, yet he did not have a fever or the typical signs of a stomach infection. When doctors examined him, they found that his stomach was full of fluid because nothing could pass through into his intestines. Scans of his abdomen revealed a cystic lump in the head of his pancreas, which was pressing against the nearby duodenum, the first part of the small intestine. This pressure had caused the intestine to narrow dangerously, creating a blockage. The images also showed a rare anatomical variation where a ring of pancreatic tissue surrounded the intestine, a condition known as an annular pancreas, along with enlarged lymph nodes that appeared to be dying in the center.

The medical team faced a difficult decision. The combination of the pancreatic mass, the blockage, and the patient's weight loss strongly suggested pancreatic cancer. Standard tests, including blood work and multiple attempts to take a tissue sample using a needle guided by ultrasound, failed to provide a clear answer. The needle biopsies came back inconclusive, leaving the doctors unable to rule out cancer. Because the blockage was severe and not improving with conservative care, the surgeons decided to operate. They performed a complex procedure called a pancreaticoduodenectomy, which involves removing the head of the pancreas, the duodenum, and part of the bile duct to relieve the obstruction and remove the suspicious mass. The surgery took over ten hours, and the patient lost a moderate amount of blood, but the operation was completed successfully.

Once the tissue was removed and examined under a microscope, the true nature of the disease was revealed. Instead of cancer cells, the pathologists found clusters of immune cells forming structures called granulomas, along with areas of dead tissue and tiny bacteria that stained red with a special dye. Further testing using genetic technology confirmed the presence of the tuberculosis bacteria complex. The diagnosis was revised from a presumed cancer to pancreatic tuberculosis. The patient recovered from the surgery, though he experienced a minor, manageable leak from the remaining pancreas. He was then started on a standard nine-month course of antibiotics designed to kill the tuberculosis bacteria. Two years later, he remains healthy, with no sign of the disease returning and a good quality of life.

This case highlights how difficult it can be to distinguish between an infection and a tumor when they look so similar. The researchers noted that while the patient had old, healed scars of tuberculosis in his lungs, the active disease in his pancreas did not show the classic signs of fever or night sweats often seen in other forms of the illness. The blockage in his intestine was caused by the chronic inflammation and swelling from the infection, combined with the unusual ring of pancreatic tissue he was born with. The study suggests that when doctors see a pancreatic mass accompanied by swollen lymph nodes that have died in the center, they should consider tuberculosis as a possibility, even if the patient has no other obvious signs of the disease.

The paper emphasizes that the best way to avoid unnecessary major surgery is to get a tissue sample before the operation. Using an endoscopic ultrasound to guide a needle into the mass allows doctors to look for specific signs of infection, such as the dead tissue and bacteria found in this patient. If the needle biopsy is not possible or does not give a clear result, surgery may still be needed to relieve a blockage, but the surgeons should be prepared to check the tissue while the patient is still on the operating table. If they see signs of tuberculosis during the surgery, they might be able to stop the procedure before removing the organ, sparing the patient a massive operation. For this patient, the surgery was necessary to clear the blockage, but the postoperative confirmation of tuberculosis allowed him to be treated with medicine rather than chemotherapy, leading to a full recovery. The authors conclude that with the right tests and a high level of suspicion, doctors can identify this rare condition and treat it effectively without always resorting to radical surgery.