Recurrent intracranial solitary fibrous tumor with cerebrospinal fluid dissemination. Case report.

Solitary fibrous tumor (SFT) is a benign and rare neoplasm. To date, only 37 patients with intracranial SFTs have been reported. Although a number of the tumors were recurrent and some later underwent malignant transformation, none of these lesions progressed to cerebrospinal fluid (CSF) dissemination. In this paper the authors report a case of SFT in which the lesion recurred several times and ultimately was disseminated by the CSF. The patient was a 63-year-old woman with multiple intracranial and spinal tumors. Fifteen years before this presentation, at the age of 48 she had been hospitalized for resection of a falcotentorial tumor. During the ensuing 15 years she underwent multiple surgeries and sessions of radiation therapy for recurrent lesions. The exclusive location of her tumors in the subarachnoid space at the end of this 15-year period indicate CSF dissemination of the tumor. The tumor that was resected when the patient was 48 years old and the latest resected lesion were analyzed by performing immunohistological CD34, epithelial membrane antigen, vimentin, S100 protein, and reticulin staining, and determining the MIB-1 labeling index (LI). Most of the results were identical, and both tumors were diagnosed as SFT according to a staining pattern that showed a strong and diffuse positive reaction for CD34. Nevertheless, the authors noted that the MIB-1 LI increased from less than 1% in the original tumor to 13% in the latest tumor. The increased proliferation of MIB-1 indicates that the malignant transformation could have occurred during tumor recurrence with CSF dissemination.

Decreased cerebrospinal fluid glutamine levels in patients with benign brain tumors.

CSF glutamine concentrations were studied in 12 patients with benign brain tumors (meningioma, craniopharyngioma, or osteofibroma), 12 patients with malignant brain tumors (astrocytoma, medulloblastoma, pinealoblastoma, or chondrosarcoma), 9 patients with noncerebral tumors, and a reference group of 24 patients. The mean +/- SD levels in the benign tumor group (424 +/- 124 microM) were significantly lower (p less than 0.0004) than those in the reference group (642 +/- 195 microM). There was no significant difference between the CSF glutamine concentrations in the malignant cerebral tumor group (643 +/- 210 microM) or noncerebral tumor group (599 +/- 127 microM) and those in the reference group. In patients with benign brain tumors there was indication of an inverse linear relationship between the logarithm of CSF glutamine concentration and tumor diameter.