Tuberculomas

Case contributed by A.Prof Frank Gaillard

Presentation

Headaches

Patient Data

Age: 30 years
CT

Innumerable contrast enhancing lesions of varying sizes are seen throughout the supratentorial and infratentorial brain. Lesions are seen in cortical, subcortical and deep white matter locations. The larger lesions demonstrate rim enhancement. Several nodules appear intraventricular in location, including at the foramina of Monro, posteriorly in the third ventricle and at the floor of the fourth ventricle.

A 14 mm rim enhancing lesion is seen in the region of and appearing to compress the right foramen of Monro, with upto 5mm of midline shift to the left at this level.

The third ventricular lesion measures 10 mm and appears to compress the cerebral aqueduct, resulting in hydrocephalus of the third and lateral ventricles.

There are several regions of white matter hypodensity with the appearance of reactive edema throughout the affected areas. There is fluid opacification of the left middle ear cavity and left mastoid air cells.

MRI

Innumerable rim enhancing, thick-walled lesions of variable size are demonstrated throughout the cerebral parenchyma bilaterally, in both a supra and infratentorial distribution. The largest of these lesions measures 14mm x 13mm and is seen anterosuperior to the third ventricle, immediately inferior to the right lateral ventricle, and compressing the right foramen of Monro.

The lesions are relatively isointense to grey matter on T1 and hypointense on T2/FLAIR. No convincing diffusion restriction is identified; certainly, the largest lesion described above does not restrict. There is a significant volume of FLAIR hyperintense signal surrounding the lesions and surrounding the dilated lateral ventricles (transependymal edema).

A tectal lesion also noted and contributing to the obstructive hydrocephalus. There is slight effacement of the 4th ventricle resulting from a lesion immediately anterior.

Fluid fills the mastoid air cells and middle ear cavity in keeping with mastoiditis/otitis media.

Conclusion:

The most likely cause of this appearance in a returned traveler is neurocysticercosis (lack of cystic component suggests this would be granular-nodular stage) with an unrelated, second pathology of left mastoiditis/otitis media. Alternatively, the possibility of infective mastoiditis as the primary pathology causing secondary cerebral abscesses should be considered, but lack of diffusion restriction on DWI make this atypical and thus raises the possibility of an atypical infective etiology such as TB.

CT

Complete opacification of the left middle ear cavity as well as the aditus ad antrum and mastoid air cells. No bony erosion. The tegmen mastoideum and tympani are intact. The right petrous temporal bone is unremarkable. 

CT

Both lungs demonstrate numerous small pulmonary nodules, the largest lying in the apical segment of the right lower lobe measuring approximately 5mm. There is no evidence of cavitation or calcification. No focal consolidation. No pleural or pericardial effusion.

Diffuse abnormal mixed fluid and soft tissue infiltrate is seen within the right axilla. This is associated with multiple ring-enhancing lesions which have central low attenuation suggesting necrosis. There is surrounding loss of the fat planes with possible extension into some of the surrounding musculature in the apex of the right axilla.

No left axillary, mediastinal, hilar or retrocrural lymphadenopathy. The visualized portions of the upper abdominal viscera are unremarkable. No suspicious bony abnormality.

Conclusion:  The findings are not specific. The differential diagnosis still includes infection, in particular, atypical organisms, such as TB and metastatic disease.

Case Discussion

The patient went on to have a lumbar puncture which confirmed the diagnosis of tuberculosis (see below). Specifically, the presence of low T2 signal, absent diffusion restriction are in keeping with a diagnosis of tuberculomas rather than tuberculous abscesses

The patient was commenced on antimycobacterial therapy. 

Lumbar puncture

MICROSCOPIC DESCRIPTION:

The smears contain moderate numbers of lymphocytes, monocytes, neutrophils, eosinophils, plasma cells and red blood cells. There are no granulomas. No microorganisms are seen in the Giemsa stain. No malignant cells are identified. DIAGNOSIS: Cerebrospinal fluid: Active inflammation.

CSF CELL COUNT:

  • Erythrocytes 10 x10^6/L
  • Polymorphs 11 x10^6/L
  • Lymphocytes 42 x10^6/L

GRAM STAIN:

  • No organisms seen.

ANTIGEN TESTING MPT64: 

  • M.tuberculosis Complex DETECTED

NUCLEIC ACID TESTING Mycobacterium Sp. by DNA Probe:

  • Positive for Mycobacterium tuberculosis

MYCOBACTERIUM CULTURE SCREEN MGIT bottle:

  • Positive (<16 days). Mycobacterium tuberculosis isolated. 

INDIAN INK PREPARATION:

  • Encapsulated yeasts NOT Detected

CRYPTOCOCCAL SEROLOGY:

  • Cryptococcal Ag: NOT Detected 
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Case information

rID: 48097
Published: 30th Jul 2018
Last edited: 6th Jan 2019
Inclusion in quiz mode: Included

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