Tuberculoma
A tuberculoma is a clinical manifestation of
With the passage of time, Mycobacterium tuberculosis can transform into crystals of calcium. These can affect any organ such as the brain,[4][5] intestine,[6][7][8] ovaries,[9][10] breast,[11][12][13] lungs,[14][15] esophagus,[16] pancreas,[17] bones,[18][19] and many others. Even with guideline-directed treatment they often persist for months to years.[3]
Mechanism
The exact mechanism of tuberculoma development has not been determined, although multiple theories have been proposed. It is possible that, following an initial tuberculosis infection resulting in bacteremia, a foci of granulomatous inflammation may coalesce into a caseous tuberculoma.[20] Pulmonary tuberculomas may arise due to repeated cycles of necrosis and re-encapsulation of foci, or, alternatively, the shrinkage and fusion of encapsulated densities. [21]
In regards to CNS tuberculoma, it is thought that mycobacterium tuberculosis is capable of penetrating the blood brain barrier after bacterial bacilli induce the release of cytokines by various immunologic cells, leading to an increase in barrier permeability.[22] Similar to pulmonary tuberculomas, small lesions eventually coalesce and undergo both necrosis and enlargement.[22]
Signs and symptoms
Symptoms are based on the location of the tuberculoma. Small, scattered lesions may be asymptomatic. Intracranial tuberculomas in children are often infratentorial, occurring near the cerebellum and base of the brain. In this population, symptoms such as headache, fever, focal neurologic findings and seizures have been seen[3] in addition to papilledema with or without meningitis.[20] When the size of a brainstem tuberculoma grows to the point of narrowing the fourth ventricle, obstructing hydrocephalus and its related symptoms can arise.[20] Rupture of tuberculomas adjacent to the arachnoid can lead to arachnoiditis,[23] while rupture near the subarachnoid space or ventricular system can cause meningitis.[22]
Diagnosis
The diagnosis of tuberculoma can be challenging, as invasive testing may be required and, occasionally, concomitant malignancy may be present.[21] In children with tuberculoma, CXR is often normal despite a positive TST/IGRA.[3]
Diagnosis of brain tuberculoma can be aided with PCR of cerebrospinal fluid, but is of less utility for quickly diagnosing and treating lesions.[22] When CSF is analyzed in patients with suspected tuberculoma, high protein concentrations and cell counts are often seen.[24]
Definitive diagnosis can be made through stereotactic, CT-guided biopsy, with excision required in rare cases. Biopsy is chosen when non-invasive testing has failed to produce a diagnosis, when patients fail to respond to a treatment regimen, in cases of drug-resistant tuberculosis, and in non-compliant patients.[22]
Imaging
The appearance of a tuberculoma on imaging can vary according to the composition and age of the mass. They may appear as either non-caseating or solidly
Magnetic resonance imaging (MRI) is another useful imaging modality for diagnosing and characterizing of tuberculomas, especially solid caseous necrosis in which 3 zones of varying intensity are seen.[22]
Treatment
Tuberculoma is commonly treated through the
Exceptionally large tuberculomas, those exerting a mass effect on the brain, and those which fail to respond to medical management required surgical excision. In some cases, surgical excision is necessary for diagnosis as well as treatment.[3] When intracranial pressure rises in the setting of tuberculoma, removal is considered a surgical emergency.[22]
Prognosis
Of patients with a brain tuberculoma treated with an appropriate medication regimen, almost half recover completely. Approximately 10% of those treated fail to recover and succumb to the tuberculoma.[22] Reports issued before the advent of effective anti-tuberculosis therapy showed that, when untreated, 30-50% of tuberculomas enter and remain in a stationary course.[21]
Epidemiology
Tuberculomas are most commonly seen in areas where tuberculosis is endemic. In these areas, tuberculomas can account for between 30%-50% of intracranial masses.[22][3] India and parts of Asia are two areas where tuberculomas have been noted to be particularly prevalent.[20] They occur most often as solitary, infratentorial lesions in young children.[3] In contrast, lesions are most often supratentorial in adults.[3]
Pulmonary tuberculomas are among the most common benign nodules, with 5%-24% of all resected nodules being of tuberculous origin.
References
- PMID 6720729.
- PMID 21624773.
- ^ OCLC 1145905400.)
{{cite book}}
: CS1 maint: location missing publisher (link - PMID 17008487.
- PMID 22069437.
- PMID 17865239.
- PMID 20871197.
- PMID 22942611.
- PMID 18055741.
- PMID 23878702.
- PMID 19561892.
- PMID 19578668.
- PMID 17577397.
- S2CID 21083607.
- PMID 20582171.
- PMID 19568514.
- PMID 17588265.
- PMID 19890413.
- PMID 22448060.
- ^ PMID 36256788, retrieved 2022-10-31
- ^ S2CID 16186172.
- ^ PMID 34900500.
- ^ OCLC 324998368.
- ^ OCLC 1023628139.)
{{cite book}}
: CS1 maint: location missing publisher (link - OCLC 1235762322.)
{{cite book}}
: CS1 maint: location missing publisher (link - PMID 26029627.