Lymphomatoid granulomatosis (LyG) is a rare multisystemic angiocentric and angiodestructive B lymphoproliferative disease that was first described by Liebow in 1972. Disease was then in the "gray zone" between vasculitis and lymphoproliferative disease.
LyG is currently categorized as a primary B lymphoproliferative disease associated with Epstein-Barr (EB) virus according to the World Health Organization (WHO) classification of tumours.