The proportion of proliferating cells in malignant non-Hodgkin's lymphomas (NHL) was determined in situ by immunostaining with the monoclonal antibody Ki-67, which reacts with a nuclear antigen that is present only in proliferating cells. A highly significant correlation could be demonstrated between the proportion of Ki-67 positive cells and the classification into high and low-grade NHL according to the Kiel classification. 93.8 per cent of high-grade and 88.5 per cent of low-grade malignancies were correctly allocated to these groups using the percentage of Ki-67 positive cells as discriminant parameter. On the basis of the medians, the degree of proliferation also paralleled the succession of entities within the Kiel classification. Within most of these different entities, however, the ranges of Ki-67 positive cells varied considerably, indicating that the growth fractions within these groups are rather heterogeneous. Thus it might be useful to determine the growth fraction of each individual case of NHL, because this might be of prognostic value.

Antibodies, Monoclonal↗

PubMedDate not supplied

Neoplastic and reactive follicles within B-cell malignant lymphomas. A morphological and immunological study of 30 cases.

Thirty cases originally diagnosed as B-cell lymphomas, either LP immunocytoma, centrocytic (Cc), or centroblastic-centrocytic (Cb/Cc), containing follicular structures of an uncertain nature were critically reviewed using both morphological criteria and immunological techniques. In particular, they were tested by conventional antisera for detection of immunoglobulins in paraffin sections and also, in the 5 cases in which frozen material was available, by a panel of monoclonal antibodies. At the first histological evaluation the cases were divided into two groups. Group A consisted of 12 examples which showed homogeneous features and, because of the neoplastic nature of the follicular structures, could be classified as follicular centroblastic-centrocytic lymphomas with marked plasmacellular differentiation. Group B comprised 18 cases which at onset of disease revealed a mantle-fashion growth around reactive-appearing follicles formed by polytypic germinal centre cells. On closer examination, however, this group appeared heterogeneous: 13 cases displayed cytological and immunological findings consistent with the diagnosis of Cc and usually contained polytypic plasma cells; 5 cases were examples of LP immunocytoma consisting of monotypic elements only. Therefore, the so-called mantle-zone lymphoma does not appear to be an entity.

Antibodies, Monoclonal↗

PubMedDate not supplied

Immunosialadenitis (Sjögren's syndrome) and lymphoproliferation.

The association of primary salivary gland non-Hodgkin's lymphoma (NHL) and immunosialadenitis (myoepithelial sialadenitis, MESA) is well recognized. Within MESA the whole spectrum of lymphoproliferation starting with a prelymphoma transforming into an early lymphoma and later on into a manifest lymphoma can be observed. These lymphomas represent so-called low grade B-cell lymphomas of mucosa associated lymphoid tissue (MALT), an entity also including lymphoplasmocytoid immunocytoma according to the Kiel classification of NHL. In a few patients a transition into a high grade B-cell lymphoma may occur. The recognition of early stages of lymphomas and their distinction from reactive MESA is only possible by application of immunohistological methods.

B-Lymphocytes↗