Mediastinal lymphoma: the smears show very large lymphoid cells, with prominent nucleoli, and basophilic cytoplasm, with small lipid vacuoles in some cells, specially in the M-G-G stained ones. The coarse chromatin is well demonstrated in the Papanicolaou stained smears. The immunophenotype was CD10+, CD19+ and CD20+, CD21- and HLA-DR-; TdT immunochemistry was negative.This case of B-cell mediastinal lymphoma is unusual because the advanced age of the patient. The spread to the pleura is not unusual.