# August 2026 - Link: https://isnr.in/august-2026/ - Published: 2026-08-11T10:07:20+05:30 - Author: ISNR ## **CASE HISTORY** • 53 year old female came with complaints of imbalance while standing and walking since 2 months. Patient was anaemic. No other co-morbidities. No significant past history. • Patient underwent MRI brain imaging followed by whole body FDG PET-CT study. ## Authors 1. Dr Shilali M S, Department of Radiology, Manipal Hospitals, Kanakapura Road, Bangalore. 2. Dr Lakshmikanth G N , Consultant, Department of Radiology, Manipal hospitals, Kanakapura Road, Bangalore. 3. Dr Chaitra P Adiga, Consultant, Department of Radiology, Manipal hospitals, Kanakapura Road, Bangalore. 4. Dr Yashwanth A N, Consultant, Department of Radiology, Manipal hospitals, Kanakapura Road, Bangalore. 5. Dr Sharath Kumar GG, HOD and Senior Consultant, Department of Radiology, Manipal Hospitals, Kanakapura Road, Bangalore. ![](https://isnr.in/wp-content/uploads/2026/08/isnr1.png) ![](https://isnr.in/wp-content/uploads/2026/08/isnr2.png) ![](https://isnr.in/wp-content/uploads/2026/08/isnr3.png) ![](https://isnr.in/wp-content/uploads/2026/08/isnr4.png) ## DESCRIPTION A & B – T2 and FLAIR axial images showing a well defined intra-axial heterogeneous and iso-hypointense lesion in the right high frontal lobe( mid cingulate gyrus ) with adjacent vasogenic edema. C & D –  DWI and ADC images showing no restricted diffusion. E – Post contrast T1 images showing irregular rind of peripheral enhancement with central non enhancing necrotic areas.  Mild enhancement of adjacent falx cerebri was also noted. F : SWI images showing no areas of blooming. G : Arterial spin labelling study showing no areas of hyper perfusion in the lesion or surrounding brain parenchyma H : MR spectroscopy showing raised choline peak with raised choline to creatinine ratio. Lipid –lactate peak noted. ## DESCRIPTION : 18F FDG PET-CT study I – A tracer avid peripherally enhancing centrally necrotic mass lesion in the right high frontal lobe (mid cingulate gyrus) and adjacent vasogenic edema. J – Tracer avid irregular enhancing circumferential wall thickening seen involving the hepatic flexure and proximal transverse colon. K – Low grade tracer avid lesion in spleen.  L – Tracer avid lesion in the anterior cortex of the interpolar region of the left kidney. M : Multiple tracer avid enlarged bilateral common iliac lymph nodes. ## Final diagnosis: Disseminated Tuberculosis with cerebral tuberculoma ![](https://isnr.in/wp-content/uploads/2026/08/Picture-1.png) ## **TUBERCULOMA –THE GREAT MASQUERADER** **Discussion: **  **Background: **Cerebral tuberculomas are granulomatous mass lesions resulting from hematogenous dissemination of Mycobacterium tuberculosis. On neuroimaging, tuberculomas can closely mimic primary or secondary intracranial neoplasms, particularly when presenting as solitary ring-enhancing lesions with surrounding vasogenic edema. Disseminated tuberculosis involving multiple organ systems may further complicate diagnosis by simulating metastatic malignancy on cross-sectional and metabolic imaging. ## Key differentiating features | **Imaging Parameter** | **Tuberculoma** | **Metastasis** | | T2 signal | Often T2 hypointense (caseating granuloma) | Usually T2 hyperintense necrotic center | | Lesion morphology | Conglomerate lesions common | Discrete lesions common | | Meningeal enhancement | Relatively common | Uncommon | | DWI | Variable | Usually no central restriction | | Perfusion (rCBV) | Low | Increased | | MR spectroscopy | Prominent lipid-lactate peak; lower Cho/Cr compared to aggressive tumors | Markedly elevated choline; higher Cho/Cr | | 3.8 ppm peak on MRS | May be present | Rare | | PET uptake | Can be intensely avid | Often avid | | Ancillary findings | TB elsewhere, meningitis, tuberculomas | Known systemic malignancy | In our case, the combination of a solitary necrotic ring-enhancing cerebral lesion with extensive perilesional edema and multiple FDG-avid extracranial lesions initially suggested metastatic disease. However, several features favoured tuberculosis, including absence of hyperperfusion on ASL, a prominent lipid–lactate peak on MR spectroscopy, lack of intralesional haemorrhage, mild adjacent falcine enhancement, and multisystem FDG-avid involvement compatible with disseminated tuberculosis. Histopathology ultimately confirmed the diagnosis. **_Teaching point :_** **_In endemic regions, a ring-enhancing lesion demonstrating low perfusion, T2 hypointense caseating components, and a dominant lipid-lactate peak should strongly raise suspicion for cerebral tuberculoma, even in the presence of multifocal FDG-avid systemic lesions suggestive of metastatic disease._** ## REFERENCES • Koesbandono, Muljadi R, Sutanto R, et al. **Intracranial tuberculomas: review of MRI findings and clinical features.** _Clinical Radiology_. 2024;79(5):354-362. A recent comprehensive review of MRI characteristics of intracranial tuberculomas. • Sankhe S, Baheti A, Ihare A, et al. **Perfusion Magnetic Resonance Imaging Characteristics of Intracerebral Tuberculomas and Its Role in Differentiating Tuberculomas from Metastases.** _Acta __Radiologica_. 2013;54:307-312. Demonstrated significantly lower perfusion parameters in tuberculomas compared with metastases. • Morales H, Alfaro D, Martinot C, et al. **MR spectroscopy of intracranial tuberculomas: A singlet peak at 3.8 ppm as potential marker to differentiate them from malignant**** tumors****.** _Neuroradiology Journal_. 2015;28:294-302. Showed lower Cho/Cr ratios and a characteristic 3.8-ppm peak in tuberculomas compared with malignant tumors. • Kumar V, Chawla S, Shah J, et al. **Differentiation of tubercular infection and metastasis presenting as ring-enhancing lesions by diffusion and perfusion MRI.** _Journal of Neuroradiology_. 2010;37:167-171. Demonstrated the value of combining diffusion and perfusion imaging in differentiating tuberculomas from metastases.