Intravascular histiocytosis.

The majority of cases of intravascular lymphomatosis are B-cell lymphomas with only the occasional case being of T-cell type. We report a case of intravascular lymphomatosis in which the proliferating cells were of histiocytic type; the tumour has recurred following treatment.

CD40 expression in Hodgkin's disease.

CD40 is a transmembrane protein that belongs to a superfamily of proteins related to nerve growth factor receptor. CD40 is expressed on B cells and some B cell malignancies. It appears to be involved in B cell proliferation and the prevention of apoptosis in germinal center cells, which is accompanied by expression of bcl-2. Its expression is up-regulated by the EBV protein latent membrane protein-1 and cytokines interleukin-4 and interferon-gamma. The expression of CD40 in 37 cases of Hodgkin's disease and 23 cases of non-Hodgkin's lymphoma (11 T cell lymphomas and 12 B cell lymphomas) was examined by paraffin section immunohistochemistry using the BB-20 monoclonal antibody. In 26 of 37 cases of Hodgkin's disease the Reed-Sternberg cells showed strong membrane or cytoplasmic expression of CD40. Only 3 of 23 non-Hodgkin's lymphomas showed any expression of CD40 and then only weakly. There was no correlation between expression of bcl-2 or latent membrane protein-1 with CD40 expression. These results show that there is probable hyperexpression of CD40 in Hodgkin's disease and suggest that dysregulation of CD40 expression may play a role in the pathogenesis of Hodgkin's disease.

Fatal haematemesis arising from benign oesophagoatrial fistula.

An 86 year old woman with a Barrett's oesophagus, a benign oesophageal stricture, and a benign ulcer developed an oesophagoatrial fistula. As in previously reported cases, she died after a massive haematemesis.