Sézary syndrome with early immunoblastic transformation.

Two patients with clinical manifestations of Zézary syndrome are reported. In both cases from an early stage of the disease in addition to characteristic Sézary cells large numbers of immunoblasts were present in skin lesions and peripheral lymph nodes and in one case also in the blood. Their relationship to the characteristic Sézary cells was shown by morphological, cytochemical and immunological methods. The infiltrates in the skin were epidermotropic in one case and nonepidermotropic in the other. Lymph node structure was effaced by diffuse infiltration of abnormal lymphoid cells. These were found to proliferate in the skin as well as in lymph nodes. Cytogenetical studies of blood lymphocytes indicated an abnormal hypodiploid clone in both cases. Immunologically the tumour cells had properties of peripheral T-lymphocytes but whereas all abnormal cells exhibited inducer/helper cell characteristics in one case, only a minority of the lymphocytes revealed these characteristics in the other case. In this case the tumour cell population changed into a more pleomorphic type. The classification of the cases is discussed.