Neoplastic angioendotheliomatosis. Report of two autopsy cases with special reference to the origin of atypical cells.

Two autopsy cases of neoplastic angioendotheliomatosis (NAE) were presented. Both patients were elderly woman, characterized by an ascending progression of transverse myelopathy and abnormal brain shadows similar to metastatic tumor in computer tomographic examination in Case 1, and by typical clinical features of cerebral infarction in Case 2. Postmortem examinations of both cases revealed an exclusive intravascular distribution of large atypical cells in generalized organs, especially in the central nervous system, and associated multiple cerebral infarcts and, in Case 1, widespread demyelination of the spinal cord. There were no distinct lesions suggestive of a primary focus. In both cases only a few atypical cells were immunohistochemically positive for factor VIII-related antigen, likely due to non-specific absorption of serum factor VIII into the cells. On the other hand, almost all of the atypical cells were immunoreactive for LN-1, LN-2, and leukocyte common antigen, suggestive of lymphocytic (B cell) origin.