[Malignant centroblastic and immunoblastic lymphoma. Results of a direct immunofluorescence study of 43 samples after inclusion in paraffin].

The immunosecreting character of tumour cells was shown using a direct immunofluorescent technique on histological sections of fixed tissue, included in paraffin, of 43 specimens from 39 patients suffering from highly malignant ML. These ML corresponded, in the Lennert-Kiel classification, to immunoblastic (9 cases, 4 in plasmoblastic transformation) or polymorphic centroblastic ML (34 cases). In seven patients, the highly malignant ML was secondary to a low grade malignancy ML (3 CLL; 1 lymphoplasmocytic ML; 1 centroblastic centrocytic follicular ML) or to previous dysimmune state (1 Gougerot-Sjögren syndrome 1 lymphomatoid granulomatosis of Liebow). Of these 43 specimens from diverse tissues, but predominantly lymphatic lymph nodes (22 cases), 14 did not contain any monoclonal intracytoplasmic immunoglobulin (12 polymorphic centroblastic ML; 2 immunoblastic ML). On the other hand, 8 immunoblastic ML and 21 polymorphic centroblastic ML did secrete a monoclonal immunoglobulin. Among the 29 cases, 23 contained a heavy chain associated with only one light chain. In one case of Richter's syndrome, a double population, one mu, the other gamma, associated to only the light chain Kappa, was demonstrated. The heavy chain mu was secreted in 25 cases out of 29, associated 19 times to a Kappa chain and 4 times to a Lambda chain. The authors stress the morphological aspects of the positive fluorescent reactions, which plead in favour of a real secretion by the cells: perinuclear border with small grains projecting into the nucleus; intranuclear vacuoles; positive cytoplasmic reactions with more or less confluent granules, predominantly perinuclear.(ABSTRACT TRUNCATED AT 250 WORDS)