Persistence Pays: Diagnosing Tuberculous Meningitis after 11 Negative Polymerase Chain Reaction Evaluations

Managing tuberculous meningitis (TBM) is challenging because of its poor prognosis and the difficulty in making an early diagnosis due to the low sensitivity of cerebrospinal fluid (CSF) polymerase chain reaction (PCR) evaluations. A 75-year-old woman presented with fatigue and multiple enlarged lymph nodes and was initially suspected of having metastatic cancer of unknown primary origin. Differential diagnoses included carcinomatous meningitis, neurosarcoidosis, and TBM, as suggested by the presence of multiple enhancing cerebral nodules. Despite 11 negative PCR evaluations, including nested PCR of CSF and biopsied lymph nodes within the first 3 days of empirical anti-tubercular treatment, TBM was eventually confirmed by CSF cultures 32 days later. This case highlights the need for repeated sampling.