Malignant angioendotheliomatosis (intravascular lymphomatosis) clinically simulating primary angiitis of the central nervous system.

Primary angiitis of the central nervous system (PACNS) and malignant angioendotheliomatosis (MAE) are two unrelated and lethal diseases that frequently affect the brain. Both are uncommon and both require histologic documentation of their characteristic lesions for a definitive diagnosis. Because brain biopsies are not routinely included in the diagnostic workup of non-neoplastic CNS diseases, a number of unconfirmed nonvasculitic conditions may mimic PACNS. To my knowledge, MAE simulating PACNS clinically and angiographically has not been previously reported, and 3 such cases are described herein.