Fig. 3
Ascitic fluid of a 52-year-old male patient with retroperitoneal lymphadenopathy and no history of a tumor. a Sediment smear showingfew normal mesothelial cells and numerous small lymphocytes (Papanicolaou, original magnification ×400) with a low proliferative activity (MIB1 <5%; not shown). b FC demonstrating a large CD19-positive B-cell population with λ chain restriction and coexpression of CD5. c FISH analysis with the fusion probe IgH-CCND1 showing fused signals in lymphoma cells (arrows) on sediment smears, indicating the presence of the t(11;14) translocation, diagnostic for Mantle cell lymphoma. Nuclear expression of cyclin D1 was demonstrated immunocytochemically on a cell block (not shown).