Which of the following statement on lymphoma is not true?

Classification system of Hodgkin's disease is ANN ARBOR staging system The prognosis of Non-Hodgkin's lymphoma varies markedly with various histological types of Non Hodgkin's lymphoma. In general lymphomas with a follicular histological pattern are of lower grade (longer survival than those of diffuse pattern). Clinical difference between Hodgkin's and Non Hodgkin's lymphoma: Hodgkin's lymphoma Non Hodgkin's lymphoma More often localized to a single axial group of cervical, mediastinal, para-aoic nodes More frequent involvement of multiple peripheral nodes Orderly spread by contiguity Non contiguous spread Mesenteric nodes and Waldeyer ring rarely involved Waldeyer ring and mesenteric nodes commonly involved Extra-nodal involvement uncommon Extra-nodal involvement