Large cell (T - cell) lymphoma is a malignant neoplasm derived from activated lymphoid cells, involving lymph nodes, spleen, subcutaneous lesions. Ultrastructural examination facilitates the determination of this particular type of lymphoma, specifically by the presence of lytic granules in the cytoplasm containing proteins involved in the target cell destruction. One of these, expressed specifically is TIA-1, a cytotoxic granule-associated protein with RNA binding domains initially identified using a monoclonal antibody reactive with a 15KD protein present in the granules of cytotoxic lymphocytes.

Tissue from seven cases of large cell lymphoma from the archives of our department were fixed for electron microscopy studies with a mixture of4% paraformaldehyde and 1% glutaraldehyde in 0.1M sodium cacodylate buffer and embedded either in Poly/Bed 812 with osmium tetroxide postfixation, or in LR White without osmication. For immunogold labelling, ultrathin sections placed on Nickel grids were incubated with a murine monoclonal TIA-1 antibody (1:50) (Coulter Co) overnight at 4°C.