Diagnostic problems in multiple sclerosis. Two cases with clinical diagnosis of MS showing only a diffusely growing malignant astrocytoma.

Two cases are presented with a long clinical history of multiple sclerosis (MS) before the diagnosis of an intracranial brain tumor. In the subsequent brain autopsy, however, both cases presented a diffusely growing anaplastic astrocytoma, only, and no changes similar to MS were seen. Diffuse tumor growth was noted in periventricular brain tissue and extended down to pons or medulla. Immunohistochemically, a positive staining for glial fibrillar acidic protein was observed in both cases and in the second case, which presented an increased amount of cerebrospinal fluid IgG, also a positive staining for immunoglobulins was seen. These case histories and subsequent neuropathological findings are presented as examples of diagnostic difficulties in MS, especially in cases with diffusely growing gliomas.