Elevated Cancer Antigen 125 (CA125) Levels in an Indian Male: A Diagnostic and Therapeutic Marker in Extrapulmonary Tuberculosis.

A patient with ascites and evening chills presenting to OPD was suspected of having tuberculosis (TB) peritonitis after ruling out possible diagnoses. Abdominal paracentesis for molecular studies, including PCR and CBNAAT (cartridge-based nucleic acid amplification test), was negative. Based on previous evidence and investigation findings from our case, we report the value and application of cancer antigen 125 (CA125) in the diagnosis and follow-up of this case of extrapulmonary TB. This case highlights the potential role of CA125 as a supportive diagnostic and prognostic marker in extrapulmonary TB. The non-invasive and cost-effective nature of CA125 may aid in monitoring anti-tubercular therapy response, an alternative to invasive investigation techniques.