In February, 2003, a 61-year-old woman presented at our hospital with abdominal pain. Her past medical history was unremarkable. A physical examination and CT scan showed generalised lymphadenopathy with a retroperitoneal bulky tumour without the involvement of any other organ. Laboratory tests showed moderate anaemia (haemoglobin concentration 11·2 g/L) and an IgM/ monoclonal gammopathy (7·33 mg/L). No signs of nephrotic syndrome, renal failure, arthritis, congestive heart-failure, or coagulopathy were detected. A supraclavicular lymph node and a bone-marrow trephine were taken, fixed in 10% buffered formalin for 24 h, and then paraffin-embedded. The patient was diagnosed with nodal marginal-zone lymphoma (NMZL) stage IVA and received eight cycles of CIOP chemotherapy (cyclophosphamide, idarubicin, vincristine, prednisolone). At the patient’s last follow-up (October, 2003), she was in a good condition with stable disease, although the lymph node was only slightly smaller. The IgM/ value had decreased (3·90 g/L) compared with the concentration measured at presentation. Histological analysis of the lymph-node biopsy sample showed almost complete destruction of the normal structure because of the deposition of hyaline material, which stained positively with periodic acid Schiff (with and without diastase digestion), Van Gieson, and toluidine blue, but not with Congo red. Furthermore, the hyaline material was more abundant around the small vessels (figure 1A, 1B). Atypical lymphoid elements with a monocytoid profile were mixed with the hyaline deposition, either singly or in small aggregates, and contained some blast cells and numerous plasma cells (figure 1C). By use of the paraffin-embedded sections of biopsied lymph-node tissue, immunohistochemical analysis, and the alkaline phosphatase antialkaline phosphatase complex (APAAP) technique, the atypical elements were found to express the IRTA1 (immunoglobulin superfamily receptor translocationassociated 1) molecule, CD20, CD79a, CD45RA, CD27, IgM/ , and BCL2. The tissue was negative for IgG, IgD, Ig light-chain, BCL6, CD10, DBA44, CD5, and CD3 (figure 1D–G and figure 2A–C). About 15% of the cells expressed Nodal marginal-zone lymphoma associated with monoclonal light-chain and heavy-chain deposition disease