[Immunoblasts. Morphology and significance in reactive and proliferative syndromes of lymphoid tissues].

The term immunoblast created by Dameshek, is useful in routine cytological and histopathological practice, for the diagnosis of lymphadenites and malignant blood diseases. This term designates a group of cells, the appearance of which is quite different from other cells of the lymphoid tissue. Their morphological characteristics are precise and they resemble transformed lymphocytes. These immunoblasts are derived from T and B lymphocytes. Using purely morphological methods the type B of certain immunoblasts may be suggested. Immunoblasts of the clear centers of follicles, immunoblasts undergoing plasma cell transformation, tumour cells constituting nodular immunoblastosarcomas, immunoblasts appearing in the tumor population of the myelomas and of Waldenström's macroglobulinaemia. The term immunoblast which evokes precise morphological criteria, should be maintained. This term cannot designate only B lymphocytes, but also transformed lymphocytes of type B or T.