To provide histological diagnoses of
brain diseases, CT-guided stereotactic brain biopsy (CT-SBB) has been widely used because of its less invasive technique compared with open brain biopsy (OBB). However, CT-SBB is not always diagnostic. We report a case of multiple
intracranial tuberculoma whose diagnosis was not made by CT-SBB but by OBB. The patient is a 46-year-old man with
insulin-dependent diabetes mellitus who had been receiving
immunosuppressive agents (
azathioprine,
cyclosporin, and
prednisolone) after
renal transplantation for diabetic
renal failure for 9 years. He gradually developed febrile,
headache and
unsteady gait. Brain MRI demonstrated multiple intracranial lesions involving left fronto-temporal and right parietal lobes, left cerebellar hemisphere, and the fourth ventricle. Although the MRI findings were consistent with those of previously reported cases of
intracranial tuberculoma, other conditions, such as
malignant lymphoma and
toxoplasmosis, were not ruled out. Therefore, CT-SBB targeting the left temporal lobe lesion was done for definitive diagnosis, but it revealed only mild perivascular infiltration of mononuclear cells and
hemorrhage. He was transferred to our clinic for further evaluation. On examination, mild truncal and
limb ataxia on the left were noted in addition to the neurological findings corresponding to
diabetic retinopathy and neuropathy. Despite vigorous laboratory examinations, including repeated bacterial cultures and PCR of cerebrospinal fluid, no evidence of tuberculous
infection was obtained. A tentative diagnosis of multiple
intracranial tuberculoma was made, and anti-tuberculous drugs (
isoniazid 400 mg,
ethambutol 750 mg, and
pyrazinamide 1.5 g) were administered. Since his symptoms deteriorated because of ventricular dilatation resulting from the enlarged lesion in the fourth ventricle after a temporary clinical improvement, VP-shunting and OBB from the left temporal lobe lesion were done. The excised lesion was firmly encapsulated and the histological examination revealed typical pathology of
tuberculoma. Ziehl-Neelsen staining and PCR for Mycobacterium tuberculosis of the biopsied specimen were also positive. Further administration of increased doses of anti-tuberculous drugs (
isoniazid 600 mg,
ethambutol 500 mg,
pyrazinamide 2.0 g and
intramuscular injection of
streptomycin 0.3 g twice a week) eventually ameliorated the symptoms and shrank the lesions. In case of
intracranial tuberculoma, the needle of CT-SBB may not penetrate the firm
capsule of
tuberculoma and only the surrounding brain tissue may be obtained as in the present case. Therefore, it is recommended to consider OBB from the beginning for definitive diagnosis of
intracranial tuberculoma. Paradoxical worsening of the clinical and laboratory findings of
tuberculosis in spite of appropriate anti-tuberculous
therapy as seen in the present case has been described in both pulmonary and
extra-pulmonary tuberculosis. The phenomenon, called transient worsening, could happen and we have to keep it in mind during the treatment of intracerebral
tuberculoma.