Intraventricular tuberculous abscess : a case report.

GV Vajramani, BI Devi, T Hegde, V Santosh, N Khanna, MK Vasudev 
 Departments of Neurosurgery, Neuropathology, Microbiology and Neuroradiology, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India., India

Correspondence Address:
G V Vajramani
Departments of Neurosurgery, Neuropathology, Microbiology and Neuroradiology, National Institute of Mental Health and Neurosciences, Bangalore, 560029, India.
India

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::   Introduction

Ventricular involvement in neurotuberculosis can occur in different ways. Juxta ependymal focus of Rich causes meningitis by rupturing into the subarachnoid spaces. lt may also cause variable degree of inflammation of the ependyma of the ventricular surface and the choroid plexus. Common feature of the tuberculous meningitis include granular ependymiti and choroid plexus covered by a gelatinous exudate.[1],[2] Well formed intraventricular tuberculoma is extremely rare and only a few cases have been recorded. However, intraventricular tubercular abscess has rarely been reported.

::   Case report

A 26 year old woman was seen elsewhere in April 1997 with history of fever of two months duration, neck pain of 7 days duration and double vision of 4 days duration. She was conscious, had neck stiffness and bilateral 6th nerve paresis. Fundus examination was normal. Lumbar puncture CSF revealed 250 cells with lymphocytic predominance, sugar of 35 mg % and proteins of 874 mg %. The antimycobacterial and anticysticercal antibodies were negative. Cranial CT scan revealed an hypodense ring enhancing lesion in the right lateral ventricle with mild obstructive hydrocephalus. The lesion had caused obstruction of foramen of Monro and resulted in enlargement of right lateral ventricle. The septum pellucidum was pushed to the left side [Figure 1]. She was started on anti-tubercular drugs and steroids. She presented two months later with features of increased intracranial tension (ICT) and was referred to our hospital. Examination at our hospital revealed a conscious patient with presence of left lateral rectus palsy. Repeat cranial CT scan showed no change in the size of lesion. The ventriculomegaly had increased as compared to the previous scan. She underwent a right frontoparietal parasagittal craniotomy, using inter-hemispheric, trans-callosal approach and total excision of the lesion. The lesion was attached to the septum in close proximity to the foramen of Monro. The choroid plexus was free.



Gram staining of the abscess content showed pus cells without any evidence of bacteria. Ziehl-Neelsen staining revealed acid fast bacilli. Fungal stain did not reveal any hyphae. Grossly, the lesion was globular, firm and measured approximately 1.5 cms in diameter. Cut surface revealed a central necrotic zone containing purulent exudate which was surrounded by a thick capsule resembling a bacterial abscess. Histologicaly, this encapsulated abscess had a central necrotic area around which florid granulation tissue comprising proliferating fibroblasts and capillaries was present. The granulation tissue was infiltrated by polymorphs, lymphocytes, plasma cells and foamy histiocytes [Figure 2A]. Attempted granuloma formation with epitheloid cells were seen at foci [Figure 2B], though, characteristic epitheloid granuloma with Langhans type giant cells was absent. Outermost zone of the abscess contained dense fibrous tissue. Postoperatively she became dull and apathetic. Repeat CT scan showed evidence of persistent unilateral hydrocephalus without any residual abscess. A ventriculoperitoneal shunt was performed. She improved in sensorium after the shunt. She was discharged from the hospital on anti tubercular drugs for a further period of 14 months.

::   Discussion

Small tubercles on the choroid plexus have been described by various authors. In an autopsy study, Kment found evidence of choroid plexus tubercles in as many as 60 % of the cases,[3] though clinical and experimental studies of Tandon et al[4] and Behar et al[5] failed to confirm these findings. Intraventricular tubercles have been described in autopsy studies by various authors.[3],[4],[5],[6],[7] Well formed intraventricular tuberculoma is extremely rare and only a few cases have been recorded. Berthier reported four cases of large intraventricular tuberculoma in children.[8] Of these, three cases had tuberculoma in the frontal horn attached to the ependyma and the septum and one had a thalamic tuberculoma extending into the ventricular body. Though some authors have described tuberculoma and tubercular abscess as part of same pathology, intraventricular tuberculous abscess has not been described earlier.



Tuberculous abscess is defined as a lesion containing frank pus, not associated with clinical meningitis.[9],[10] Our patient had frank clinical meningitis and intraventricular tuberculous abscess simultaneously. The origin of intraventricular tuberculoma or abscess is not clear. It may arise from enlargement of a small choroid plexus tubercle or a subependymal tubercle. Three of the Berthier's cases had lesions within the frontal horns where the choroid plexus is absent. Probably those arose from the subependymal or septal tubercle.[8] In the present case too, the lesion arose from the septum. At surgery the choroid plexus was free from the lesion. There have been numerous case reports of tubercular abscess in HIV positive patients.[11] Our patient however, was HIV negative. Traction of the septum pellucidum towards the lesion has been described as a feature that seems to confirm the existence of adhesive process, allowing tuberculomas to be differentiated from other intraventricular masses on CT scans.[8] This feature was not seen in the present case where the septum was pushed contralaterally because of the unilateral hydrocephalus. The hydrocephalus in our patient appears to be due to impaired CSF absorption from meningitis and obstructed intraventricular CSF circulation due to the abscess. Preoperative diagnosis could be made in the present case because of the associated features namely the clinical symptoms, lumbar CSF findings and the CT picture.



Management of intraventricular tuberculous abscess of sizeable conFigureuration consists of surgical excision and prolonged anti-tubercular drugs. The hydrocephalus associated with it may or may not resolve with surgical excision depending on the presence or absence of scarring associated with ependymitis and the cause of the hydrocephalus. In the present case, the hvdrocephalus did not resolve in the postoperative period because of the associated meningitis and this necessitated a CSF diversion procedure.

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