brain tuberculoma has previously accounted for up to a third of new intracranial lesions in areas endemic with tuberculosis , but is unexpected in the united states and other western countries with improved control of systemic disease . here we show the importance of considering this diagnosis in at - risk patients , even with no definitive pulmonary involvement . a 24 year - old man who had immigrated from ethiopia six years prior presented to our emergency department with intermittent left leg shaking for two days . he was previously healthy and had no history of fever , chills , night sweats , or weight loss . he was well appearing with no abnormal findings on physical and neurological examination . a computed tomography ( ct ) scan showed right frontoparietal edema . a contrast - enhanced scan was performed , revealing an associated frontoparietal enhancing mass . magnetic resonance imaging ( mri ) of the brain demonstrated a 2.61.6 cm mass with surrounding edema ( figure 1 ) . ct of chest , abdomen , and pelvis revealed periceliac and peiraortic lymphadenopathy , and questionable but no definitive pulmonary nodules . having received the bacillus calmette - gurin vaccine , his tuberculin sensitivity test was positive . he was started on levetiracetam for treatment of simple partial seizures , and dexamethasone for treatment of vasogenic edema . he underwent right parietal craniotomy with intraoperative monitoring for resection of the lesion and tissue diagnosis . opening the dura revealed a superficial mass with well defined margins that easily peeled away from the underlying parenchyma ( figure 2 ) . pathological examination demonstrated necrotizing granulomas with peripheral palisading epithelioid histiocytes , giant cells , and acid fast bacilli , consistent with cerebral tuberculoma ( figure 3 ) . he completed a six - month regimen of isoniazid , rifampin , ethambutol , and pyrizinamide , and was doing well without neurological sequelae five months after completion of therapy . the tuberculoma is a parenchymal reaction to hematogenous seeding of the brain surface , with its indolent course differing from and only occasionally associated with tubercular abscesses or meningitis . it may arise from the conglomeration of several so - called miliary tubercles , i.e. , incipient tuberculomas , around the outer sheaths of small cerebral blood vessels , with eventual central caseation and fibrous encapsulation . the larger masses may be more prone to central caseation , leading to purulent transformation and abscess formation . there may be vasculitis , giant cell systems and outward extension with plaque formation against the meninges , which can become inflamed but are otherwise relatively impervious . geographic and temporal patterns of brain tuberculomas have followed the dynamic trends of the systemic disease , influenced by socioeconomic development , public health measures and , in recent decades , association with hiv infection . in the united states and other western countries with improved control of tuberculosis , these cases are understandably rare and unexpected , potentially leading to delayed diagnosis and treatment . in nonendemic areas the majority of central nervous system tuberculosis involves adult immigrants from areas of high prevalence , as was exemplified by the patient in the current report . nonimmigrant cases generally involve immunosuppressed adults , most often due to hiv , but also associated with alcoholism , diabetes mellitus , malignancy , or use of steroids or agents blocking tumor necrosis factor activity . several very thorough descriptions of large series of brain tuberculomas have come from authors practicing in areas endemic to the disease in the last century . in india in the 1950 s and 1960 s , tuberculomas accounted for almost one third of space occupying lesions in the brain , comparable to the number of newly diagnosed gliomas . the majority of our understanding of the disease process comes from reports such as these , since during the same period one western author noted only three cases at a british neurosurgical service that had treated 2200 intracranial tumors . since that era there have been decreasing numbers of reports , as a pubmed search revealed only five non - overlapping large case series with at least 50 patients in the contemporary english medical literature , i.e. , the last five decades . without concomitant meningitis , brain tuberculomas closely resemble neoplasms , causing seizures , progressive focal neurological deficits , and occasionally refractory edema or increased intracranial hypertension . the differential diagnosis among these patients is that of almost any ring - enhancing lesion , generally indistinguishable from other equally plausible causes within endemic and non - endemic areas , such as lymphoma , glioma , bacterial or fungal abscess , neurocysticercosis , or toxoplasmosis . given the lack of systemic evidence for active tuberculosis , we had favored the diagnosis of glioma in this patient preoperatively . the majority of tuberculomas are isodense to brain parenchyma on ct scan , with variable calcification . mri characteristics are diverse and dependent upon the amount of caseation , but most t1-weighted images show an isointense core with a hypointense rim , and most t2-weighted images show a hypointense core with a hyperintense rim , which may be dificult to distinguish from some stages of cerebritis or cerebral abscess , including tubercular abscess . these lesions commonly occur in the cerebral or cerebellar hemispheres , with a greater predilection for the infratentorial compartment .   in this case the dura was not grossly involved despite the superficial location , but there are reports describing meningeal nodules and unusual sites such as within the ventricles . lumbar puncture often has a low diagnostic yield for tuberculoma and , given the significant perilesional edema and mass effect in the current patient , did not have a favorable riskbenefit ratio in this case . previous authors have found that , although protein may be elevated , definitive acid - fast bacilli are inconsistently found in cerebrospinal fluid in cases of tuberculoma without meningitis . similarly , lumbar puncture is often not useful for primary brain tumor , which was also a consideration preoperatively . prior to effective antituberculous therapy , decompression alone without resection was recommended because of a high risk of resultant meningitis . in endemic locations where suspicion for tuberculoma is high with any newly discovered intracranial lesion , surgical excision or biopsy is usually reserved for when the diagnosis is in doubt or there is no response to empiric medical therapy for at least two months . open or stereotactic biopsy is generally agreed upon as a minimum initial step in regions where such lesions are uncommon , but could still potentially be deferred in clear cases of reactivation of dormant tuberculosis . in cases of immunocompromise such as hiv , the wide differential diagnosis of enhancing brain lesions almost always necessitates brain biopsy for diagnosis . given the low incidence and high association with hiv in the united states , only rarely will cases be diagnosed and treated preoperatively . in the current case , preoperative imaging revealed a very superficial lesion that we surmised could be removed in its entirety with a small craniotomy , without any additional operative time or morbidity compared to that of open biopsy . a gross total resection was preferred in order to achieve greater survival benefit if pathological examination would have revealed malignant glioma . when diagnosis certain , isoniazid , rifampin , and pyrazinamide penetrate cerebrospinal fluid and are considered the mainstay of treatment , while the benefits of less penetrating agents such as ethambutol and streptamycin are not proven . the optimum time for antibiotic therapy has not been clearly established . for tuberculous meningitis , six months of therapy is probably sufficient , although many authors recommend a year of treatment . for intracranial tuberculomas , recent recommendations on duration of therapy have come from expert opinion and small case series . one retrospective study of 18 patients in saudia arabia demonstrated radiographic resolution of all tuberculomas after one year of antituberculous therapy . authors of a study of 17 patients in the united states with central nervous system tuberculosis , including nine tuberculomas , recommended prolonged anti - tuberculous therapy for 18 months . with resurgence of tuberculosis cases in the united states and other western countries , intracerebral tuberculoma should remain a diagnostic consideration in at - risk patients with new space occupying lesions , even in the absence of definitive pulmonary involvement or cerebrospinal fluid evidence . mass lesions causing neurological sequelae can be safely addressed surgically and followed with antituberculosis therapy .
brain tuberculoma has previously accounted for up to a third of new intracranial lesions in areas endemic with tuberculosis , but is unexpected in the united states and other western countries with improved disease control . here 
 we show the importance of considering this diagnosis in at - risk patients , even with no definitive pulmonary involvement . 
 we describe a young man who presented with partial seizures and underwent craniotomy for resection of a frontoparietal tuberculoma . 
 he subsequently completed six months of antituberculosis therapy and was doing well without neurological sequelae or evidence of recurrence five months after completion of therapy . 
 with resurgence of tuberculosis cases in the united states and other western countries , intracerebral tuberculoma should remain a diagnostic consideration in at - risk patients with new space occupying lesions . 
 mass lesions causing neurological sequelae can be safely addressed surgically and followed with antituberculosis therapy .