INFLAMMATORY PSEUDOTUMOR OF THE CENTRAL-NERVOUS-SYSTEM - CLINICOPATHOLOGICAL STUDY OF ONE CASE AND REVIEW OF THE LITERATURE

A 58-year-old male who had been diagnosed as having polymyositis was f ound to have a mass in the fourth ventricle. This mass showed features of an inflammatory pseudotumour. This lesion has been described in ma ny parts of the body including the central nervous system. This case s howed some features different from the previously reported cases in th e central nervous system (i.e. presence of necrosis and association wi th polymyositis) which may throw some light on the pathogenesis of the condition. Inflammatory pseudotumour is most likely to be caused by a n exaggerated immunological process and is sometimes associated with h igh levels of serum immunoglobulin.