Glioblastoma multiforme disguised as sarcoidosis: pitfalls in diagnosis.
A 45-year-old man presented with dyspnea on exertion and dry cough for 2 months. A chest x-ray showed bilateral upper lobe infiltrates. A pulmonary function testing was done that showed restrictive physiology with moderately reduced diffusion capacity. A computed tomography scan of the chest also showed bilateral pulmonary infiltrates. There was no hilar or mediastinal lymph node enlargement. Bronchoscopy with transbronchial lung biopsy was done. Bronchoalveolar lavage cultures were negative. Biopsy showed a granulomatous pneumonitis consistent with sarcoidosis. The patient was a nonsmoker. He had no history of exposure to chemicals. The patient's past medical history was unremarkable. Physical examination on presentation was normal. Prednisone 40 mg daily was started. One month after presentation, the patient's respiratory symptoms improved. Prednisone was tapered to 20 mg daily. Six months after presentation, the patient developed generalized seizure. Cerebral magnetic resonance imaging (MRI) showed diffuse meningeal enhancement and periventricular white matter lesions. Cerebral MRI also showed small 1.5 cm lesion in suprasellar region. CSF analysis was normal. Neurosarcoidosis was suspected. Treatment with prednisone 100 mg daily and methotrexate 5 mg weekly were initiated. Methotrexate dose was gradually increased to 12.5 mg weekly. Seven months after presentation, the patient developed diplopia, left hemiparesis, left 3rd cranial nerve palsy, left facial nerve palsy, and memory loss. Repeat cerebral MRI again showed diffuse meningeal enhancement and periventricular white matter lesions. The suprasellar mass showed marked enlargement (Fig.). There was also a new left temporal cortical abnormality. Treatment with methylprednisolone 1000 mg daily for 5 days for presumed refractory neurosarcoidosis did not result in any improvement. Biopsy of new temporal lesions showed glioblastoma multiform.
The clinical, radiographic, and CSF manifestations of neurosarcoidosis are nonspecific and overlap with other central nervous system pathologies. Diagnosis of neurosarcoidosis is usually considered in patients with pulmonary or extrapulmonary sarcoidosis and neurologic findings compatible with neurosarcoidosis. The pathology of meningeal and brain involvement in neurosarcoidosis shows characteristic non-necrotizing granulomas. Although brain biopsy is not routinely recommended, in selected cases it is extremely helpful to include or exclude neurosarcoidosis. The presence of intracranial mass or progression of lesions on therapy should alert the clinicians to an alternative diagnosis.
Bobbak Vahid, MD
Sandra Weibel, MD
Department of Pulmonary and Critical
Thomas Jefferson University Hospital
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|Title Annotation:||Letters to the Editor|
|Publication:||Southern Medical Journal|
|Date:||Mar 1, 2007|
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