Concurrent intra-cranial tuberculoma and tuberculous abscesses: A rare combination.

Dear Sir,

Although tuberculosis of the central nervous system is well-known, the incidence of tuberculous brain abscesses (TBAs) is rare, more so its association with concurrent intra-cranial tuberculoma.

A 6-year-old immunocompetent child with contact history of tuberculosis, presented to us in unconscious state with complains of intermittent fever, night sweats, headache, left sided weakness and progressive visual impairment in both eyes for last 4 months. Two days back he had several episodes of left sided complex partial seizure, following which he became unconscious. Neurological evaluation showed a decorticating child with secondary optic atrophy. Plain computed tomography (CT) scan revealed right fronto-parietal multiple cystic lesions with a separate solid component [Figure 1a]. There was perilesional edema, midline shift and herniation. An urgent craniotomy was done, straw colored cystic fluid aspirated followed by removal of multiple cysts one after another. All the cysts were well encapsulated having clear cyst-parenchyma interface. Solid component was firm, yellowish white, avascular and well demarcated. It was removed in piecemeal totally [Figure 2]. Postoperative CT scan confirmed total removal of the lesion with relief of hydrocephalous [Figure 1b]. Histopathological examination of solid component showed a granulomatous inflammation with central caseous necrosis, containing epithelioid cells and multinucleated giant (Langhans) cells, whereas the histopathological examination of cyst wall showed chronic inflammatory cells without granuloma formation [Figure 3]. Ziehl Neelsen staining of pus revealed the acid fast bacilli and pus cells [Figure 4]. Patient's screening for any systemic source of tuberculosis was negative. Postoperatively child improved clinically. He was discharged with anti-tubercular regimen (Category II regimen of DOTS) started and continued for 15 months. At 2 years follow-up, the patient was doing well.

Figure 1

(a) Plain computed tomography (CT) scan showing right fronto-parietal multiple cystic lesions (red arrow) with a separate solid component (blue arrow), perilesional edema, midline shift and herniation. (b) Postoperative CT scan showing complete removal of lesion with relief of hydrocephalous

Figure 2

Well encapsulated excised cyst wall, solid granulomatous mass and pus in syringe

Figure 3

Histopathological examination of abscesses wall showed chronic inflammatory cells without granuloma formation

Figure 4

The Ziehl Neelsen stain of pus showing many acid-fast bacilli and pus cells

After Whitener[1] reviewed the world literature, isolated cases of TBAs have been reported.[234] TBA, by definition, is an abscess containing tubercle bacilli in the pus but the lack of granulomas in the wall. All these criteria were met during diagnosis of TBA in the present case report.

The diagnosis of tuberculous brain abscess is, usually, suspected in immunocompromised patients with or without human immunodeficiency virus infection or in an immunocompetent patient from an endemic region with a pulmonary focus of infection. This pulmonary focus of infection is, usually, present in only 30% of cases.[5] In the absence of an extracranial focus of infection, it might be very difficult to suspect tuberculous brain abscess on the basis of clinical and imaging features as they resemble pyogenic brain abscesses. In vivo proton magnetic resonance (MR) spectroscopy and magnetization transfer MR imaging may differentiate tuberculous from pyogenic abscesses and influence management.[6] Newer techniques like polymerase chain reaction may provide a useful tool for diagnosis of tuberculosis from paucibacillary specimens like pus in which conventional methods may show low sensitivity.[7] Recently in vitro proton MR spectroscopy was evaluated for the diagnosis of TBA. Absence of multiplet of amino acids-lipids at 0.9 ppm seems to be a hallmark of TBA.[8]