The Burkholderia cepacia complex comprises environmental non-fermenting Gram-negative bacilli associated with opportunistic infections in immunocompromised hosts 1212. Pericardial involvement is extremely rare 3. In tuberculosis-endemic regions, malignant and infectious effusions pose significant diagnostic challenges 413. We report an unusual case of Burkholderia cepacia complex isolated from pericardial fluid in a patient with lung adenocarcinoma with metastasis.

A 50-year-old female from Moregaon presented with dry cough for two months, fever for one month, and Grade III dyspnoea for three weeks. She had a 25-year history of tobacco (misri) use and occupational exposure to smoke from burning agricultural leaves.

On admission, the patient had cough, cold, body ache, and Grade III dyspnoea requiring oxygen support. Physical examination revealed bilateral crepitations.

Burkholderia cepacia complex is an opportunistic non-fermenting Gram-negative bacillus known for intrinsic antimicrobial resistance and survival in moist environmental and healthcare settings 12712. Infection predominantly occurs in immunocompromised hosts.

In this case, two states were present. The primary factor was lung adenocarcinoma with metastasis, associated with impaired cellular immunity and malignant effusion formation. The second factor was chronic hepatitis B infection, which may further impair immune responses through chronic inflammation and immune dysregulation 815. The coexistence of these conditions likely predisposed the patient to opportunistic infection.

A key clinical question remains how BCC entered the pericardial space in the absence of cardiac surgery or invasive procedures. Possible mechanisms include hematogenous dissemination from transient bacteremia or contiguous spread from adjacent pulmonary pathology. Agricultural environmental exposure may also have contributed to colonization followed by opportunistic invasion.

An important diagnostic challenge was distinguishing true infection from contamination. Although BCC can exist as an environmental organism, several findings supported pathogenicity in this case:

· Isolation from a sterile anatomical site

· Compatible clinical illness

· Exclusion of tuberculosis and other pathogens

· Sterile pleural fluid cultures

· Clinical improvement after targeted antimicrobial therapy

Together, these factors strongly support true infection rather than laboratory contamination.

Malignant effusions are typically sterile unless secondary infection develops 913. This case highlights the importance of routine microbiological analysis even when malignancy is confirmed. Early identification enabled targeted therapy guided by susceptibility testing performed under clinician request using CLSI 2024 criteria 6.

Tubercular pericarditis was excluded through negative molecular testing and low ADA levels, an essential consideration in endemic regions 410.

Burkholderia cepacia complex may rarely infect the pericardial space in patients with lung adenocarcinoma with metastasis, particularly in the presence of chronic hepatitis B infection. Although malignant pericardial effusions are generally considered sterile, secondary opportunistic infections should be suspected when clinical symptoms persist.

The absence of prior cardiac intervention raises important questions regarding pathogenesis and suggests possible hematogenous or contiguous spread in susceptible hosts. Clinical improvement following targeted antimicrobial therapy further supports the organism’s pathogenic role rather than contamination.

Comprehensive microbiological evaluation of pericardial fluid remains essential for accurate diagnosis and management. Multidisciplinary collaboration between clinicians, microbiologists, and pathologists is crucial for optimal care. Recognition of such rare infections expands clinical understanding and supports evidence-based management of complex oncological patients.14