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Giant eccentric target sign A 36-year-old woman presented with fever, headache, neck pain, and lethargy for 3 weeks. She had focal seizures with jerking of the left upper limb and twitching of the left half of the face 4 weeks after the onset of illness. The contrast enhanced MRI showed multiple ring enhancing lesions with eccentric mural nodules (described classically as the eccentric target sign) of varying sizes in both the cerebral hemispheres [Figures 1 and 2]. Almost all the ring enhancing lesions showed eccentric mural nodules of varying sizes [Figure 3]. The serum was positive for human immunodeficiency virus (HIV)1 and HIV2 and antitoxoplasma antibody IgG was found in the serum. A provisional diagnosis of cerebral toxoplasmosis was considered and pyrimethamine therapy was advocated. Follow-up scan showed resolution of the lesions. The pathological correlate of this imaging sign has been described as the central enhancing core of the target produced by a leash of inflamed vessels extending down the length of sulcus. This was surrounded by concentric zones of necrosis and a wall composed of histiocytes and proliferating blood vessels with impaired permeability producing the peripheral enhancing rim.[1]
Figure 1: Coronal contrast-enhanced magnetic resonance imaging (MRI) showing multiple ring-enhancing lesions with eccentric nodule suggestive of eccentric target sign. Note the linear vascular “leash” in the coronal image (arrow) supportive of the pathologic correlate described in literature
Figure 2: Axial contrast-enhanced MRI showing multiple ring-enhancing lesions with eccentric nodule suggestive of eccentric target sign
Cerebral toxoplasmosis is one of the most common opportunistic infections in patients having an HIV infection. It closely mimics on MR imaging, central nervous system (CNS) lymphoma, metastasis as well as other granulomatous infections in the brain such as tuberculosis.[2] An early diagnosis is important as immediate and early institution of therapy leads to a better prognosis. However, the sensitivity of the sign is approximately 30%.[3]
Ramakrishna Narra, Suseel Kumar Kamaraju Department of Radiology, Katuri Medical College, Guntur, Andhra Pradesh, India Address for correspondence: Dr. Ramakrishna Narra, Department of Radiology, Katuri Medical College, Guntur - 522 019, Andhra Pradesh, India. E-mail: [email protected]
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Figure 3: Axial contrast-enhanced MRI showing multiple ring-enhancing lesions with eccentric nodule suggestive of eccentric target sign
References 1.
Kumar GG, Mahadevan A, Guruprasad AS, Kovoor JM, Satishchandra P, Nath A, et al. Eccentric target sign in cerebral
Neurology India / January 2015 / Volume 63 / Issue 1
[Downloaded free from http://www.neurologyindia.com on Thursday, March 05, 2015, IP: 202.177.173.189] || Click here to download free Android application for this journal Narra and Kamaraju: Giant “Eccentric Target” sign in cerebral toxoplasmosis
2.
3.
toxoplasmosis: Neuropathological correlate to the imaging feature. J Magn Reson Imaging 2010;31:1469-72. Bargalló J, Berenguer J, García Barrionuevo J, Ubeda B, Bargalló N, Cardenal C, et al. The "target sign": Is it a specific sign of CNS tuberculoma? Neuroradiology 1996;38:547-50. Ramsey RG, Gean AD: Neuroimaging of AIDS. I. Central nervous system toxoplasmosis. Neuroimaging Clin N Am 1997;7:171-86.
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Neuroimage
Giant eccentric target sign A 36-year-old woman presented with fever, headache, neck pain, and lethargy for 3 weeks. She had focal seizures with jerking of the left upper limb and twitching of the left half of the face 4 weeks after the onset of illness. The contrast enhanced MRI showed multiple ring enhancing lesions with eccentric mural nodules (described classically as the eccentric target sign) of varying sizes in both the cerebral hemispheres [Figures 1 and 2]. Almost all the ring enhancing lesions showed eccentric mural nodules of varying sizes [Figure 3]. The serum was positive for human immunodeficiency virus (HIV)1 and HIV2 and antitoxoplasma antibody IgG was found in the serum. A provisional diagnosis of cerebral toxoplasmosis was considered and pyrimethamine therapy was advocated. Follow-up scan showed resolution of the lesions. The pathological correlate of this imaging sign has been described as the central enhancing core of the target produced by a leash of inflamed vessels extending down the length of sulcus. This was surrounded by concentric zones of necrosis and a wall composed of histiocytes and proliferating blood vessels with impaired permeability producing the peripheral enhancing rim.[1]
Figure 1: Coronal contrast-enhanced magnetic resonance imaging (MRI) showing multiple ring-enhancing lesions with eccentric nodule suggestive of eccentric target sign. Note the linear vascular “leash” in the coronal image (arrow) supportive of the pathologic correlate described in literature
Figure 2: Axial contrast-enhanced MRI showing multiple ring-enhancing lesions with eccentric nodule suggestive of eccentric target sign
Cerebral toxoplasmosis is one of the most common opportunistic infections in patients having an HIV infection. It closely mimics on MR imaging, central nervous system (CNS) lymphoma, metastasis as well as other granulomatous infections in the brain such as tuberculosis.[2] An early diagnosis is important as immediate and early institution of therapy leads to a better prognosis. However, the sensitivity of the sign is approximately 30%.[3]
Ramakrishna Narra, Suseel Kumar Kamaraju Department of Radiology, Katuri Medical College, Guntur, Andhra Pradesh, India Address for correspondence: Dr. Ramakrishna Narra, Department of Radiology, Katuri Medical College, Guntur - 522 019, Andhra Pradesh, India. E-mail: [email protected]
124
Figure 3: Axial contrast-enhanced MRI showing multiple ring-enhancing lesions with eccentric nodule suggestive of eccentric target sign
References 1.
Kumar GG, Mahadevan A, Guruprasad AS, Kovoor JM, Satishchandra P, Nath A, et al. Eccentric target sign in cerebral
Neurology India / January 2015 / Volume 63 / Issue 1
[Downloaded free from http://www.neurologyindia.com on Thursday, March 05, 2015, IP: 202.177.173.189] || Click here to download free Android application for this journal Narra and Kamaraju: Giant “Eccentric Target” sign in cerebral toxoplasmosis
2.
3.
toxoplasmosis: Neuropathological correlate to the imaging feature. J Magn Reson Imaging 2010;31:1469-72. Bargalló J, Berenguer J, García Barrionuevo J, Ubeda B, Bargalló N, Cardenal C, et al. The "target sign": Is it a specific sign of CNS tuberculoma? Neuroradiology 1996;38:547-50. Ramsey RG, Gean AD: Neuroimaging of AIDS. I. Central nervous system toxoplasmosis. Neuroimaging Clin N Am 1997;7:171-86.
Access this article online Website:
Quick Response Code
www.neurologyindia.com DOI: 10.4103/0028-3886.152689 PMID: xxxxx
Neurology India / January 2015 / Volume 63 / Issue 1
125
Copyright of Neurology India is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
