Lethal midline granuloma (LMG) is an historical term for a condition in which necrotic and highly destructive lesions develop progressively in the middle of the face, principally the nose and palate. Many cases presented with ulcerations in or perforations of the palate. LMG was thought to be a manifestation of three or four different diseases: the well-characterized disease of granulomatosis with polyangiitis, the ill-defined disorders of polymorphic reticulosis or mid-line malignant reticulosis, and an incompletely defined form of non-Hodgkin lymphoma...