[Manifestation of a malignant lymphoma of high grade malignancy in the terminal stage of mycosis fungoides. Enzyme-cytochemical and immunocytological investigations (author's transl)].

Report on a patient with mycosis fungoides, in whom after a long course the disease developed rapidly into a malignant lymphoma of high grade malignancy. The diagnosis was confirmed by cytomorphological and enzyme-cytochemical methods (demonstration of hydrolytic enzymes in cryostat sections, cutaneous smears and cell suspensions extracted from skin lesions), as well as by immunocytological methods (differentiation of lymphocyte sub-populations). In the tumour stage of mycosis fungoides, a polymorphous infiltrate composed of lymphocytoid and monocytoid cells prevailed, while a proliferation of lymphoblastic cells was present in the terminal stage of the disease. These cells showed no longer the properties of mature lymphocytes and differed also in their enzyme-cytochemical pattern.