Ultrastructural features in an erythrophagocytic T4 lymphoma

Electron microscopic investigation allowed the identification and characterization of the atypical malignant cells in a case of T-cell lymphoma. The proliferating cells were endowed with characteristics belonging to two different lineages: phagocytic ability, complement receptors and ultrastructural features proper to the macrophagic lineage, and T-cell determinants (E receptors, T3, T4 and T11 antigens). The cells were peroxidase and esterase negative. The erythrocytes were partially or completely dehemoglobinized and presented the phenomenon of autolysis in different stages of evolution. Because this lymphoma is difficult to diagnose and is apparently resistant to therapy, its recognition and further study are warranted.