The peripheral blood smears, bone marrow aspirates and biopsies of 46 patients with mantle cell lymphoma were reviewed. The diagnosis of mantle cell lymphoma was established in all cases on extramedullary tissue samples using standard morphologic, phenotypic and molecular genetic criteria. 27/35 patients (77%) had circulating lymphoma cells (median 200%m of all circulating white blood cells; range 5-90%) identified by morphology at some point during the course of their disease. No statistical difference in survival was detected in patients with or without peripheral blood involvement. Lymphoma was identified in bone marrow aspirate specimens from 33/40 patients (83%) and in bone marrow biopsy specimens from 39/43 patients (91%). The pattern of marrow biopsy involvement was nodular (31 cases; 82%), interstitial (19 cases; 50%), paratrabecular (17 cases, 45%) and diffuse (12 cases; 32%). Although the median survival of patients with > or = 50% bone marrow involvement was 13 months, and the median survival of patients with < or = 50% was 49 months; no statistically significant differences between these small subgroups were observed. Mantle cell lymphoma frequently involves the peripheral blood and bone marrow. Its appearance is distinctive but variable, and immunophenotypic studies as well as morphologic confirmation by a biopsy of tissue other than bone marrow is still required for diagnosis.

We investigated whether differences in IL-6 and IL-1␤ expression could be detected in monoclonal plasma cells from patients with MGUS or MM. Expression of IL-6 and IL-1␤ in bone marrow cells was determined using cell sorting to enrich for plasma cells followed by reverse transcriptase/polymerase chain reaction (RT/PCR). Nineteen patients (six MGUS, two primary amyloid (AL), 11 MM) were studied. IL-6 mRNA expression was detectable in the sorted CD38 ؉ /CD45 ؊ plasma cell populations from 0/6 MGUS, 0/2 AL and 5/11 MM patients. All five MM patients with autocrine IL-6 expression demonstrated an elevated plasma cell labeling index. IL-1␤ mRNA was detectable in the sorted CD38 ؉ /CD45 ؊ plasma cell populations from 1/6 MGUS, 0/2 AL and 10/11 MM patients. In situ hybridization (ISH) confirmed that the IL-1␤ producing cells were plasma cells. In conclusion, autocrine production of IL-6 parallels a high labeling index and aberrant expression of IL-1␤ correlates with the diagnosis of MM. Follow-up of IL-1␤-positive MGUS patients will determine whether aberrant expression of IL-1␤ will predict those MGUS patients that will eventually progress to MM.