[Malignant peripheral T-cell lymphomas: morphologic and immunopathologic bases of the classification proposed by...

In the last few years advances in immunopathology have demonstrated the T cell origins of some malignant lymphoma (ML). Histopathological criteria have been suggested for classifying several varieties of T cell ML. Peripheral T cell ML are the result of proliferation of T cell lymphocytes with markers which distinguish between the enhancing-inducer and suppressor-cytotoxic forms. The diagnosis is made from the appearances of the cell, the presence of vascular hyperplasia and associated lesions. The numbers of small, medium and large cells and clinical follow-up of these tumors have provided a means of distinguishing between low and highly malignant tumors. Some peripheral T cell ML have associated lesions due to the secretion of lymphokines which give characteristic histopathological appearances (lympho-epithelioid T cell ML, AIL type T cell ML). The authors discuss the respective places of each variety of peripheral T cell ML in Lennert and Suchi's classification which is an extension of that proposed by Kiel, and their prognostic signification.