All of the low grade lymphomas gave positive results on staining, with clear cytoplasmic labelling for bcl-2 protein in the small neoplastic cells, some of which formed characteristic lympho-epithelial lesions.
Intensive conventional-dose chemotherapy for stage IV low-grade lymphoma: high remission rates and reversion to negative of peripheral blood bcl-2 rearrangement.
Most extensively studied have been the chromosome translocations involving the myc gene in Burkitt's lymphomas and the bcl-2 gene in low-grade lymphomas, where "activation" of the oncogene results from association with a transcriptionally active immunoglobulin gene.
While bcl-1 rearrangement was not present in these gastrointestinal lymphomas, one case of diffuse low-grade lymphoma of mucosa-associated lymphoid tissue and three cases of centroblastic lymphoma (diffuse large cell) could be shown to have detectable bcl-2 rearrangement.