Cerebellar Multiloculated Abscess and Multiloculated Intraventricular Abscess in Extrapulmonary TB
Cerebellar multiloculated abscess and multiloculated intraventricular abscess are extremely rare manifestations of extrapulmonary tuberculosis, representing an uncommon subset within an already rare disease entity.
Rarity of Tuberculous Brain Abscess
Tuberculous brain abscess (TBA) itself is exceptionally uncommon within the spectrum of central nervous system tuberculosis. In a large referral center series, TBA accounted for only 4% (6 of 149 cases) of all CNS tuberculosis cases 1. This establishes TBA as a rare manifestation even among patients with neurological TB complications.
Genitourinary TB, for context, represented only 4.6% of extrapulmonary TB cases in the European Union between 1997 and 2017 2. Given that TBA is far less common than genitourinary TB, the overall incidence is vanishingly small.
Specific Rarity of Multiloculated Presentations
Multiloculated tuberculous brain abscesses represent an even rarer subset within this already uncommon entity 3, 1. The literature documents:
- Multiloculated lesions are recognized as a distinct risk factor for abscess rupture, which carries case-fatality rates of 27-50% 2
- In one pediatric series, multiloculated TBA required total excision due to noncommunicating compartments and thick walls 3
- Among six immunocompetent adults with TBA, three patients had single deep multiloculated lesions 1
Cerebellar Location: Additional Rarity
Cerebellar tuberculous abscess is documented in isolated case reports, emphasizing its exceptional rarity 4. A 1998 case report described a 36-year-old immunocompetent woman with cerebellar TB abscess and no identifiable primary pulmonary focus, treated with surgical excision and 6 months of antituberculous therapy 4.
The posterior fossa location adds complexity, as excision may be considered for abscesses in this anatomical region according to current guidelines 5.
Intraventricular Involvement
Intraventricular abscess in TB is not specifically documented in the available literature as a distinct entity. However, rupture of brain abscess into the ventricles occurs in 10-35% of general brain abscess cases and causes fulminant meningitis with substantially increased mortality 2. Proximity to ventricles is a recognized risk factor for rupture 2.
Early meningitis findings such as high signal intensity on FLAIR along cerebellar folia or hydrocephalus may represent atypical presentations of cerebral TB that could be overlooked 6.
Clinical Context and Diagnostic Challenges
Most patients with TBA have a previous history of tuberculosis 1. In the immunocompetent adult series:
- Five of six patients had prior TB history
- Three were already receiving antituberculous treatment for pulmonary or lymph node TB when TBA was diagnosed
- Two were being treated for TB meningitis when TBA developed 1
This indicates that TBA can develop despite ongoing antituberculous therapy, occurring 3 weeks to 12 months after treatment initiation 3.
Diagnostic Approach for Suspected Cases
When encountering suspected tuberculous brain abscess with multiloculated or intraventricular features:
- Send pus samples for Ziehl-Neelsen stain, culture, and PCR for tuberculosis in endemic areas or based on clinical presentation 2
- Brain MRI with diffusion-weighted imaging and gadolinium enhancement is the preferred imaging modality 5
- Multiloculated abscesses on imaging should raise suspicion for TB, particularly with relatively long clinical history and thick enhancing capsule 3
- Consider that pyogenic abscess typically has a thin rim on contrast CT, whereas TBA has a thick wall 3
Management Implications
Total excision usually becomes necessary for multilocular noncommunicating thick-walled abscesses 3. Standard aspiration may be insufficient for these complex lesions.
Antituberculous therapy remains the mainstay of management, with 6-9 months of standard treatment recommended 4. Long-term follow-up is mandatory, as residual lesions may take a mean of 10 months to resolve on imaging 1.
Critical Pitfall
Fulminant tuberculous meningitis can develop following surgical excision of TBA, as documented in operated cases 3. This life-threatening complication requires heightened vigilance in the postoperative period.