Case report
Tubercular Cold Abscess Mimicking Baker’s Cyst: A Rare Case of Posterior Knee Swelling
RD01-RD04
Correspondence
Dr. VS Ambrish,
J-309, 3rd Floor, The Royal Castle Apartment, Thirumudivakkam, Chennai-600044, Tamil Nadu, India.
E-mail: ambrishbalakarthik2107@gmail.com
Musculoskeletal tuberculosis is usually not a common form of extrapulmonary tuberculosis which often presents with an atypical clinical features, resulting in delayed or missed diagnosis. Tubercular cold abscesses typically lack classical signs of inflammation and may clinically mimic benign cystic conditions. Posterior knee swelling is most commonly attributed to Baker’s cyst; however, in tuberculosis-endemic regions, infective aetiologies should be considered when the presentation is atypical or fails to respond to conventional treatment. Hereby, the authors report a case of a 67-year-old female who presented with a chief complaints of swelling over the posterior aspect of the knee since two years which was gradually progressive, associated with pain and restriction of knee normal range of movements. She was initially managed as a Baker’s cyst with repeated aspirations and intra-articular steroid injections, which provided only temporary relief. Magnetic Resonance Imaging (MRI) report showing a well-defined cystic lesion suggestive of a Baker’s cyst. Due to persistent symptoms and progressive enlargement, surgical excision was performed. Histopathological examination demonstrated granulomatous inflammation, and microbiological examination such as GeneXpert confirmed Mycobacterium tuberculosis with rifampicin resistance. The patient was initiated on appropriate antitubercular therapy and showed significant clinical improvement with no recurrence in six-month follow-up. The present case highlights the importance of considering tuberculosis in the differential diagnosis of persistent or atypical posterior knee swellings. Imaging alone will not be enough in arriving clinical diagnosis, may be misleading, and definitive diagnosis requires histopathological and microbiological confirmation. Early surgical intervention combined with appropriate therapy ensures favourable outcomes and prevents complications.