In recent years immunobiology has witness- aspects on the background of various meth- ed most remarkable achievements and the ods applied, as well as clinicopathologic im- understanding of lymphomas and leukemias plications. A special chapter is addressed to is greatly increased. Knowing that these Pagetoid Reticulosis elucidating the neoplasms are essentially immunoprolif- various views on the cytogenesis of this neo- plasm. For the same reason, a contribution erative diseases extended the dermatological views of the corresponding skin tumors. on Merkel Cell Neoplasms of the Skin has Sophisticated techniques and new im- been included because these tumors have munological methods now enable us to been mistaken for pagetoid reticulosis. analyze and classify cutaneous malignant The last chapter on Cooperative Study lymphomas far better than before. As a Groups, Staging and Treatment leads off consequence this has produced a vast lit- with the signmcant contribution from the erature on this subject in the last few years. Kiel Lymphoma Study Group (G. Brit- For those who are not so familiar with mod- tinger}. 1t deals with the results of a prospec- em immunological thinking, it has become tive study of nodal lymphomas which were increasingly difficult to keep abreast with classilled according to the Kiel Classmca- these developments, and a comprehensive tion. Treatment protocols applied to skin review of this subject appeared to be needed. lymphomas are reported from Cooperative This is the purpose of the present book.