Title : "The false shadows: The infection that posed as cancer" disseminated melioidosis (Lung, Soft tissue, Bone) secondary to Burkholderia pseudomallei
Abstract:
A 58-year-old male farmer with a history of hypertension, diabetes, gout, a chronic smoker and alcoholic, presented with a three-week history of intermittent low back pain, on-radiating, relieved by rest, and aggravated by movement, especially bending forward. Associated with worsening fatigue, fever, chills, non-productive cough, anorexia and weakness prompting hospital admission managed as pneumonia with Piperacillin-Tazobactam.
During the course of admission, he developed jaundice with epigastric pain radiating to the back aggravated by meals, and relieved by leaning forward. Further tests revealed elevated lipase, liver enzymes, and alkaline phosphatase. His whole abdominal CT scan showed pancreatic enlargement and multiple lung nodules, raising suspicion for a periampullary mass and possible malignancy, while Chest CT scan showed multiple pulmonary nodules, potentially metastatic lung disease from pancreatic carcinoma.
The upper gastrointestinal endoscopic ultrasound revealed duodenitis with no mass lesions, the rest showed unremarkable findings. A PET scan identified multiple hypermetabolic lung nodules, and hypermetabolic bone foci, possible bone metastasis. MRI of the lumbosacral spine indicated abnormal marrow signals, probably metastatic. Additionally, a lesion in the left iliacus was likely a chronic hematoma or myositis.
Biopsy of the lung nodule and abscess showed granulomatous changes. Special staining with Fite Faraco was positive for acid fast bacilli, but was negative for Mycobacterium tuberculosis polymerase chain reaction and culture. Routine culture of the lung nodule revealed growth of Burkholderia pseudomallei. The abscess and blood culture also had growth for this pathogen. He was treated as disseminated melioidosis co-infected with disseminated tuberculosis.
Melioidosis is a zoonotic infection caused by Burkholderia pseudomallei, a bacterium found in soil and water, endemic in Southeast Asia and Northern Australia. It spreads via percutaneous inoculation, inhalation, or ingestion. While many infections are asymptomatic, 86% are acute, and 11% are chronic. Majority are bacteremic, with 25% progressing to septic shock. Symptoms include pneumonia, skin infections, soft tissue abscesses, osteomyelitis, septic arthritis, and genitourinary issues. Diagnosis is through culture. Treatment begins with intravenous antibiotics (Ceftazidime or Meropenem) for 10-14 days, followed by Trimethoprim / Sulfamethoxazole (TMP-SMZ) for three months. This patient was treated with Ceftazidime and TMP-SMZ, but due to septic shock, Meropenem was substituted. After 5 days, blood cultures cleared, and lung nodule size regressed. He was on anti-tuberculosis therapy for co-infection. Despite these efforts, the patient ultimately succumbed to sepsis.
