Investig Magn Reson Imaging.  2015 Dec;19(4):231-236. 10.13104/imri.2015.19.4.231.

Tumor-like Presentation of Tubercular Brain Abscess: Case Report

• Karki DB
• Gurung G
• Sharma MR
• Shrestha R
• Sayami G
• Sedain G
• Shrestha A
• Ghimire RK

• KMID: 2151770
• DOI: http://doi.org/10.13104/imri.2015.19.4.231

Abstract

A 17-year-old girl presented with complaints of headache and decreasing vision of one month's duration, without any history of fever, weight loss, or any evidence of an immuno-compromised state. Her neurological examination was normal, except for papilledema. Laboratory investigations were within normal limits, except for a slightly increased Erythrocyte Sedimentation Rate (ESR). Non-contrast computerized tomography of her head revealed complex mass in left frontal lobe with a concentric, slightly hyperdense, thickened wall, and moderate perilesional edema with mass effect. Differential diagnoses considered in this case were pilocytic astrocytoma, metastasis and abscess. Magnetic resonance imaging (MRI) obtained in 3.0 Tesla (3.0T) scanner revealed a lobulated outline cystic mass in the left frontal lobe with two concentric layers of T2 hypointense wall, with T2 hyperintensity between the concentric ring. Moderate perilesional edema and mass effect were seen. Post gadolinium study showed a markedly enhancing irregular wall with some enhancing nodular solid component. No restricted diffusion was seen in this mass in diffusion weighted imaging (DWI). Magnetic resonance spectroscopy (MRS) showed increased lactate and lipid peaks in the central part of this mass, although some areas at the wall and perilesional T2 hyperintensity showed an increased choline peak without significant decrease in N-acetylaspartate (NAA) level. Arterial spin labelling (ASL) and dynamic susceptibility contrast (DSC) enhanced perfusion study showed decrease in relative cerebral blood volume at this region. These features in MRI were suggestive of brain abscess. The patient underwent craniotomy with excision of a grayish nodular lesion. Abundant acid fast bacilli (AFB) in acid fast staining, and epithelioid cell granulomas, caseation necrosis and Langhans giant cells in histopathology, were conclusive of tubercular abscess. Tubercular brain abscess is a rare manifestation that simulates malignancy and cause diagnostic dilemma. MRI along with MRS and magnetic resonance perfusion studies, are powerful tools to differentiate lesions in such equivocal cases.

Keyword

Brain abscess; Magnetic resonance imaging; Diffusion weighted imaging; Magnetic resonance spectroscopy; Perfusion imaging

MeSH Terms

Abscess
Adolescent
Astrocytoma
Blood Sedimentation
Blood Volume
Brain Abscess*
Brain*
Choline
Craniotomy
Diagnosis, Differential
Diffusion
Edema
Epithelioid Cells
Female
Fever
Frontal Lobe
Gadolinium
Giant Cells, Langhans
Granuloma
Head
Headache
Humans
Lactic Acid
Magnetic Resonance Imaging
Magnetic Resonance Spectroscopy
Necrosis
Neoplasm Metastasis
Neurologic Examination
Papilledema
Perfusion
Perfusion Imaging
Weight Loss
Choline
Gadolinium
Lactic Acid

Figure

• 

  Fig. 1 (a) Non-contrast CT scan of head revealed an irregular cystic mass with concentric slightly thick wall in the left frontal lobe with moderate perilesional edema and mass effect. (b, c) T1 weighted axial (b) and T2 weighted axial (c) delineate lobulated outline mass in left frontal lobe in anterior aspect which displayed two concentric hypointense wall in T2 and iso-signal intensity in T1. Alternating hypointense areas were noted between the wall in T1 and high signal intensity in T2 weighted images. Moderate perilesional edema with mass effect also noted. (d) FLAIR axial showed two irregular concentric hypointense wall with in between and perilesional hyperintensity. (e, f) Post contrast T1 axial (e) and post contrast T1 sagittal (f) studies showed markedly enhancing two slightly irregular wall with some nodular solid enhancing component in the anterior aspect. (g, h) DWI - b1000 (g) and DWI - ADC map (h) show no restricted diffusion was seen within this mass in DWI. (i) ASL showed decreased rCBV at the lesion. (j) DSC perfusion study showed decreased rCBV in center. No increased rCBV seen in the region of walls.

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  Fig. 2 (a, b) MRS displayed increase in lactate and lipid peaks at the central part of the mass. Few areas at the periphery of the mass shows increased choline peak without significant decrease in NAA level.

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  Fig. 3 (a) Excised organized capsulated mass of the lesion. (b) Histopathology showing discrete to confluent epithelioid cell granulomas with extensive caseation necrosis and Langhans giant cells.

Reference

1. National Tuberculosis Center. TB Burden in Nepal. Ministry of Health & Population;Accessed March 8, 2015. http://www.nepalntp.gov.np/.

2. Cherian A, Thomas SV. Central nervous system tuberculosis. Afr Health Sci. 2011; 11:116–127.

3. Jinkins JR, Gupta R, Chang KH, Rodriguez-Carbajal J. MR imaging of central nervous system tuberculosis. Radiol Clin North Am. 1995; 33:771–786.

4. Trivedi R, Saksena S, Gupta RK. Magnetic resonance imaging in central nervous system tuberculosis. Indian J Radiol Imaging. 2009; 19:256–265.

5. Bathla G, Khandelwal G, Maller VG, Gupta A. Manifestations of cerebral tuberculosis. Singapore Med J. 2011; 52:124–130. quiz 131

6. Kastrup O, Wanke I, Maschke M. Neuroimaging of infections. NeuroRx. 2005; 2:324–332.

7. Hansman Whiteman ML, Bowen BC, Donovan Post MJ, Bell MD. Intracranial infection. In : Atlas SW, editor. Magnetic resonance imaging of the brain and spine. 3rd ed. Philadelphia: Lippincott Williams & Wilkins;2002. p. 1099–1175.

8. Desprechins B, Stadnik T, Koerts G, Shabana W, Breucq C, Osteaux M. Use of diffusion-weighted MR imaging in differential diagnosis between intracerebral necrotic tumors and cerebral abscesses. AJNR Am J Neuroradiol. 1999; 20:1252–1257.

9. Holmes TM, Petrella JR, Provenzale JM. Distinction between cerebral abscesses and high-grade neoplasms by dynamic susceptibility contrast perfusion MRI. AJR Am J Roentgenol. 2004; 183:1247–1252.

10. Luthra G, Parihar A, Nath K, et al. Comparative evaluation of fungal, tubercular, and pyogenic brain abscesses with conventional and diffusion MR imaging and proton MR spectroscopy. AJNR Am J Neuroradiol. 2007; 28:1332–1338.

11. Mishra AM, Gupta RK, Jaggi RS, et al. Role of diffusion-weighted imaging and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of ring-enhancing intracranial cystic mass lesions. J Comput Assist Tomogr. 2004; 28:540–547.

12. Mishra AM, Gupta RK, Saksena S, et al. Biological correlates of diffusivity in brain abscess. Magn Reson Med. 2005; 54:878–885.

13. Floriano VH, Ferraz-Filho JRL, Ronaldo Spotti A, Tognola WA. Perfusion-weighted magnetic resonance imaging in the evaluation of focal neoplastic and infectious brain lesions. Rev Bras Neurol. 2010; 46:29–36.

14. Essig M, Nguyen TB, Shiroishi MS, et al. Perfusion MRI: the five most frequently asked clinical questions. AJR Am J Roentgenol. 2013; 201:W495–W510.

15. Detre JA, Rao H, Wang DJ, Chen YF, Wang Z. Applications of arterial spin labeled MRI in the brain. J Magn Reson Imaging. 2012; 35:1026–1037.