[Histopathology of lymphomes (author's transl)]

This histologic classification is based upon the arrangement and cytologic composition of the infiltrate. We separate diseases with intraepidermal exocytosis from diseases without intraepidermal exocytosis. In the first group, mycosis fungoides is the most important: the infiltrate is often polymorphous, but sometimes it consists of histiocytes and lymphocytes. Varying number of Sézary cells are present. The Woringer-Kolopp syndrome and histiocytosis X are included in this group as well. The second group comprises many neoplastic diseases: mycosis fungoides without Pautrier microabscesses, so-called 'reticulosis', 'Crosti's reticulosis', leukemia and lymph node lymphoma. Difficulties may arise in the differential diagnosis between these various diseases with well-differentiated lymphocytes and without intraepidermal exocytosis. These diseases must also be differentiated from the non-malignant lymphocytic infiltrates found in lupus erythematosus, lymphocytoma cutis and Jessner's lymphocytic infiltration of the skin.