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Washington University Experience | VASCULAR | Vasculitis - PACNS | 5A0 Case 5 History
Case 5 History ---- The patient was a 32 year old woman with a posterior fossa mass. Radiologic examination revealed an enhancing lesion in the inferior vermis of the cerebellum extending into the cerebellar hemisphere bilaterally. Operative procedure: Posterior fossa craniectomy for removal of mass. ---- The neurosurgical specimen showed scattered vasculitic vessels; in some areas the process completely spared vessels and others in which vessels are completely destroyed by fibrinoid necrosis. Certain vessels also showed organized thrombi in their lumina causing fibrous obliteration of the vessel. The inflammatory infiltrate is composed of a mixture of bland T and B cells. Histochemical stains for microorganisms (Gram, GMS, AFB) showed no evidence of bacteria, fungi or acid fast bacilli. Immunohistochemical stains for herpes simplex virus show no definitive evidence of viral infection. There is no evidence of neoplasm. ---- Sections of the cerebellum showed a vasculitis consistent with granulomatous angiitis. There is extensive leptomeningeal fibrosis and an inflammatory infiltrate composed predominantly of lymphocytes, scattered macrophages and neutrophils. The inflammation is centered around leptomeningeal vessels, infiltrating the vessel walls. Focally, some vessels show infiltration of their walls by histiocytes, some of which are in the form of multinucleated giant cells. The cerebellum showed multiple remote microinfarcts with disappearance of Purkinje cells and the internal granular layer and replacement of these areas by Bergman gliosis. ---- Immunohistochemical stains of the leptomeningeal infiltrate are nonreactive for synaptophysin and reactive for leukocyte common antigen, support for a mixture of T and B cells as shown by the reactivity in immunohistochemical stains for UCHL-1 and L26, T and B cell markers, respectively. The smooth muscle actin demonstrates the infiltration and destruction of the vessel walls by the inflammatory infiltrate, supported by histochemical stains for reticulin and elastin.
