Cutaneous B-cell lymphoma: pathological spectrum and clinical outcome in 51 consecutive patients.

The clinical behavior and optimal treatment of patients presenting with skin infiltration by B-cell lymphoma have not been established. To clarify this we assessed the clinical and laboratory features of 51 patients presenting with cutaneous infiltration by B-cell lymphoma. Follow-up data was available for 46 patients with a median age of 68 years (range 16-89 years) and a median follow-up of 32.5 months (range 5-123 months). Thirty-three of 51 (65%) patients had diffuse large B-cell lymphoma (DLBCL), and 15/51 (29%) had marginal zone lymphoma (MZL). The remaining 3 patients had follicular lymphoma, CLL, and post-transplant lymphoproliferative disease. Of the 33 patients with DLBCL, follow-up was available in 29; 24/29 (83%) had primary cutaneous disease, which was unifocal in 17/24 (71%). Following treatment, 8/24 (33%) of the primary cases relapsed. Of the 8 who relapsed, 7 had received local forms of treatment only. Follow-up data was available in 14/15 patients with MZL. 11/14 (79%) had primary cutaneous disease, which was unifocal in 8 (73%). Following treatment, 4 of these cases relapsed (36%); all had received local therapy only. It is evident from this study that a significant proportion ( reverse similar 20%) of patients who present with cutaneous infiltration by B-cell lymphoma have systemic disease. Staging is therefore mandatory in these patients. Approximately 1/3 patients with primary cutaneous DLBCL or MZL ultimately relapse, and relapse rates appear higher in those patients receiving local therapy only. Systemic or combined modality therapy may therefore be the most appropriate treatment at presentation. This should be assessed prospectively in randomized trials.

Waldenström macroglobulinemia. Development of diagnostic criteria and identification of prognostic factors.

To establish whether a combination of morphologic and immunophenotypic criteria could be developed to more precisely define Waldenström macroglobulinemia (WM) and prognostic factors, we retrospectively assessed the clinical and laboratory features of 111 cases of WM. Bone marrow infiltration by small lymphocytes was documented in each case; and diffuse, interstitial, nodular, and paratrabecular patterns of infiltration were documented in 58%, 32%, 6%, and 4% of cases, respectively. Ninety percent were characterized by a surface immunoglobulin-positive, CD19+CD20+CD5-CD10-CD23- immunophenotype. The median overall survival from diagnosis was 60 months; univariate analysis revealed the following adverse prognostic factors: older than 60 years, performance status more than 1, platelet count less than 100 x 10(3)/microL (< 100 x 10(9)/L), pancytopenia, and diffuse bone marrow infiltration. Associated median survival was 40, 38, 46, 28, and 59 months, respectively. Multivariate analysis revealed age, performance status, and platelet count as prognostically significant, but stratification of patients according to the International Prognostic Index had limited value. We suggest defining WM by the following criteria: IgM monoclonal gammopathy; bone marrow infiltration by small lymphocytes, plasmacytoid cells, and plasma cells in a diffuse, interstitial, or nodular pattern; and a surface immunoglobulin-positive, CD19+CD20+CD5-CD10-CD23- immunophenotype.

In multiple myeloma, only a single stage of neoplastic plasma cell differentiation can be identified by VLA-5 and CD45 expression.

The nature of the proliferating fraction in myeloma is still not known and understanding the characteristics of this fraction is central to the development of effective novel therapies. However, myeloma plasma cells typically show a very low rate of proliferation and this complicates accurate analysis. Although the level of CD45 and/or VLA-5 has been reported to identify proliferating 'precursor' plasma cells, there are discrepancies between these studies. We have therefore used a rigorous sequential gating strategy to simultaneously analyse cycle status and immunophenotype with respect to CD45, VLA-5 and a range of other integrin molecules. In 11 presentation myeloma patients, the proliferative fraction was distributed evenly between CD45+ and CD45- cells, however, cycling plasma cells were consistently VLA-5-. There was close correlation between the expression of VLA-5 and a range of other integrin molecules (CD11a, CD11c, CD103), as well as the immunoglobulin-associated molecules CD79a/b (Spearman, n = 10, P < 0.0001). In short-term culture, cells that were initially VLA-5-showed increasing VLA-5 expression with time. However, simultaneous analysis of the DNA-binding dye 7-amino-actinomycin D demonstrated that this was not as a result of differentiation, as VLA-5+ plasma cells were all non-viable. This was confirmed in freshly explanted plasma cells from nine patients. Discrete stages of plasma cell differentiation could not be distinguished by the level of CD45 or VLA-5 expression. The results indicate that there is a single stage of plasma cell differentiation, with the phenotype CD38+CD138+VLA-5-. These findings support the hypothesis that neoplastic bone marrow plasma cells represent an independent, self-replenishing population.

Use of methyl methacrylate resin for embedding bone marrow trephine biopsy specimens.

AIMS: To evaluate the use of methyl methacrylate resin as an embedding medium for undecalcified bone marrow trephine biopsy specimens. METHODS: About 2500 undecalcified bone marrow trephine biopsy specimens were processed, and embedded in methyl methacrylate resin. Semithin sections (2-3 microns) were stained by routine tinctorial and immunocytochemical staining methods with a wide range of antibodies using a standard streptavidin biotin horseradish peroxidase technique. Different antigen retrieval pretreatments were evaluated. RESULTS: Bone marrow trephine biopsy specimens are embedded routinely in methyl methacrylate at the Haematological Malignancy Diagnostic Service at The Leeds General Infirmary. Over 50 different primary antibodies are in current use; for the majority of these, microwave antigen retrieval or trypsin digestion, or both, is either essential or greatly enhances the results. CONCLUSIONS: Embedding bone marrow trephine biopsy specimens in methyl methacrylate resin retains morphology and permits reliable, high quality immunocytochemistry. This is particularly desirable for the demonstration of neoplastic cells in regenerative marrow after chemotherapy, and in the detection of residual disease after treatment. The use of methyl methacrylate for routine use on bone marrow trephine biopsy specimens is advocated.