CASE 18700 Published on 24.09.2024

TB or not TB? En plaque tuberculoma masquerading as meningioma

Section

Neuroradiology

Case Type

Clinical Case

Authors

Padma Badhe¹, Ajith Varrior¹, Abhijeet Shukla², Prabodhini Gadhari³, Moinuddin Sultan⁴

¹ Department of Radiology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India

² E.S.I.S. Hospital (E.S.I.C), Kandivali, Mumbai, Maharashtra, India

³ Department of Radiology, Grant Government Medical College and Sir J. J. Group of Hospitals, Mumbai, Maharashtra, India

⁴ Department of Radiology, Vedantaa Institute of Medical Sciences, Dahanu, Maharashtra, India

Patient

14 years, male

Categories

Area of Interest CNS ; Imaging Technique CT, MR

No Procedure ; No Special Focus ;

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Clinical History

A 14-year-old boy presented with complaints of headache, low-grade fever, and dizziness since two months. He also had multiple episodes of generalised tonic-clonic seizures. He had a history of pulmonary tuberculosis four years back, for which he had completed his course of anti-tubercular drugs. On clinical examination, there was neck rigidity.

Imaging Findings

A computed tomography of the brain showed a well-defined, lobulated, dural-based lesion in the left frontal region. It was isodense to the brain parenchyma with homogeneous enhancement. There was peri-lesional oedema without a mid-line shift. On bone window algorithm, there was irregularity and thickening of the inner table of the skull adjacent to the lesion (Figures 1a and 1b). On magnetic resonance imaging, the lesion was extra-axial with an iso to hypointense signal on T2 and FLAIR sequences (Figures 2a and 2b). It was isointense on T1 sequence with a homogeneous enhancement (Figures 3a, 3b and 3c). There was a lipid-lactate peak on spectroscopy (Figure 4). There was no diffusion restriction or susceptibility (Figures 5 and 6). The final diagnosis of tuberculosis was made on CSF PCR (polymerase chain reaction). He was started on anti-tubercular therapy and steroids.

Discussion

Tuberculosis (TB) is among the most common infectious diseases globally, particularly in developing countries. While TB primarily affects the lungs, it can also involve other areas, including the central nervous system (CNS), presenting as TB meningitis or tuberculomas [1–4].

Tuberculoma en plaque is an uncommon variant of tuberculoma, described first in 1927 by Pardee and Knox as a plaque-like meningitic process without exudation [2–12]. It resembles an en plaque meningioma at first glance, both radiologically and in gross appearance. It is common in young adults and is characterised by a lengthy clinical course [3,4]. The clinical features depend on the location and include headache, blurring of vision, vomiting, focal seizures, weakness of limbs or tilting of the neck. The optic fundi are usually normal. Fever is often present and can be a key diagnostic clue.

On radiographs, intracranial calcifications are rare. There is one case of en plaque tuberculoma with associated hyperostosis and sclerosis of the adjacent bone [8].

On contrast-enhanced CT, en plaque tuberculomas are solid enhancing lesions, and may have a lucent centre or small specks of calcification. They have been described in the frontal and parietal convexity, interhemispheric fissure, tentorium cerebelli and posterior fossa. White matter oedema and sulcal enhancement have also been described.

On MRI, there is a characteristic plaque-like extension to the meninges with marked nodular enhancement [5,6]. It is hypointense on T2 sequences [7,13,14]. On MR spectroscopy, there is a lipid-lactate peak [7,14].

Meningioma is the closest differential with similar features on CT (isodense lesion with homogeneous post-contrast enhancement) and MRI (T2 iso-hyperintense lesion). The features favouring tuberculoma over meningioma include the presence of leptomeningeal enhancement, the presence of fever and a history of TB. On spectroscopy, meningioma typically has an alanine peak without a lipid-lactate peak. Dural lymphomas are rare. Because of high cellularity, these are hyperdense on CT, hypointense on T2-weighted images and show restricted diffusion on DWI. They also show homogeneous enhancement. Dural metastases are multi-focal and are hyperintense on T2 sequences, with a history of malignancy.

CSF PCR helps in confirming the diagnosis of tuberculosis [15]. Conventional staining and culture of the TB bacillus are relatively insensitive in CNS tuberculosis due to the paucity of AFB [16].

Anti-tuberculosis therapy constitutes the mainstay of treatment for CNS tuberculosis. The regimen is usually continued for 12–30 months [4,7]. Early treatment with steroids (0.4 mg/kg/day for 1–2 weeks and tapered over the next few weeks) is recommended in patients with TB meningitis with monitoring regardless of severity, in order to significantly decrease the risk of mortality and to reduce the neurological sequelae [4,17].

Differential Diagnosis List

En plaque tuberculoma

Meningioma

Dural metastasis

Sarcoidosis

Lymphoma

Final Diagnosis

En plaque tuberculoma

References

[1] Sinh G, Pandya SK, Dastur DK (1968) Pathogenesis of unusual intracranial tuberculomas and tuberculous space-occupying lesions. J Neurosurg 29(2):149-59. doi: 10.3171/jns.1968.29.2.0149. (PMID: 5673313)

[2] Pardee I, Knox LC (1927) Tuberculoma en plaque. Arch Neurol Psychiatr 17:231–8. doi: 10.1001/archneurpsyc.1927.02200320083006

[3] Dubey S, Devi BI, Jawalkar VK, Bhat DI (2002) Tuberculoma en plaque: a case report. Neurol India 50(4):497-9. (PMID: 12577106)

[4] Aggarwal A, Patra DP, Gupta K, Sodhi HB (2016) Dural Tuberculoma Mimicking Meningioma: A Clinicoradiologic Review of Dural En-Plaque Lesions. World Neurosurg 88:686.e1-686.e7. doi: 10.1016/j.wneu.2015.10.097. (PMID: 26608386)

[5] Ng SH, Tang LM, Lui TN, Ko SF, Wong HF, Wai YY, Wan YL (1996) Tuberculoma en plaque: CT. Neuroradiology 38(5):453-5. doi: 10.1007/BF00607273. (PMID: 8837090)

[6] Whelan MA, Stern J (1981) Intracranial tuberculoma. Radiology 138(1):75-81. doi: 10.1148/radiology.138.1.7455100. (PMID: 7455100)

[7] Adachi K, Yoshida K, Tomita H, Niimi M, Kawase T (2004) Tuberculoma mimicking falx meningioma--case report. Neurol Med Chir (Tokyo) 44(9):489-92. doi: 10.2176/nmc.44.489. (PMID: 15600285)

[8] Elisevich K, Arpin EJ (1982) Tuberculoma masquerading as a meningioma. Case report. J Neurosurg 56(3):435-8. doi: 10.3171/jns.1982.56.3.0435. (PMID: 7057244)

[9] Vengsarkar US, Pisipaty RP, Parekh B, Panchal VG, Shetty MN (1986) Intracranial tuberculoma and the CT scan. J Neurosurg 64(4):568-74. doi: 10.3171/jns.1986.64.4.0568. (PMID: 3950741)

[10] Thrush DC, Barwick DD (1974) Three patients with intracranial tuberculomas with unusual features. J Neurol Neurosurg Psychiatry 37(5):566-9. doi: 10.1136/jnnp.37.5.566. (PMID: 4836751)

[11] Nayil K, Kumar K, Nair S, Rao R, Menon G (2010) Dural tuberculoma mimicking en-plaque meningioma: Case report and literature review. Neurosurgery Quarterly 20(3):180-2. doi: 10.1097/WNQ.0b013e3181eb2c29

[12] Bauer J, Johnson RF, Levy JM, Pojman DV, Ruge JR (1996) Tuberculoma presenting as an en plaque meningioma. Case report. J Neurosurg 85(4):685-8. doi: 10.3171/jns.1996.85.4.0685. (PMID: 8814176)

[13] Abebe FT, Megersa TB, Bonger MT, Guyolla YH (2022) An en-plaque tuberculoma mimicking meningioma: A case report and literature review. Interdisciplinary Neurosurgery 30:101627. doi: 10.1016/j.inat.2022.101627

[14] Chang KH, Han MH, Roh JK, Kim IO, Han MC, Choi KS, Kim CW (1990) Gd-DTPA enhanced MR imaging in intracranial tuberculosis. Neuroradiology 32(1):19-25. doi: 10.1007/BF00593936. (PMID: 2333129)

[15] Singh KK, Nair MD, Radhakrishnan K, Tyagi JS (1999) Utility of PCR assay in diagnosis of en-plaque tuberculoma of the brain. J Clin Microbiol 37(2):467-70. doi: 10.1128/JCM.37.2.467-470.1999. (PMID: 9889246)

[16] Rock RB, Olin M, Baker CA, Molitor TW, Peterson PK (2008) Central nervous system tuberculosis: pathogenesis and clinical aspects. Clin Microbiol Rev 21(2):243-61. doi: 10.1128/CMR.00042-07. (PMID: 18400795)

[17] Kim YE, Lee D, Hwang H, Kim M (2016) En Plaque Tuberculoma: a Case Report. Investig Magn Reson Imaging 20(3):200-5. doi: 10.13104/imri.2016.20.3.200

Case information

URL:	https://eurorad.org/case/18700
DOI:	10.35100/eurorad/case.18700
ISSN:	1563-4086

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This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Axial contrast-enhanced CT of the brain shows a well-defined lobulated, isodense dural-based homogeneously enhancing lesion in the left frontal region (1a). On bone window (1b), there is irregularity and thickening (spiculated) of the inner table of the skull adjacent to the lesion.

Figure 2

Axial T2 (2a) and coronal FLAIR (2b) sequences of the MRI of the brain show an iso-hypointense signal within the lesion. There is peri-lesional oedema in the underlying parenchyma.

Figure 3

Sagittal pre (3a), post-contrast sagittal (3b), and axial (3c) T1 sequence of the MRI of the brain show a dural-based lesion with isointense signal and homogeneous enhancement.