Cytogenetic studies in splenic lymphoma with villous lymphocytes

Summary. We report the cytogenetic findings on 31 cases of splenic lymphoma with villous lymphocytes (SLVL). TPA stimulated cells from peripheral blood (28 cases), spleen (two cases) and lymph node (one case) with SLVL have been analysed. A clonal chromosome abnormality was found in 27/31 patients (87%): this was identified as a simple abnormality in 12 cases and a complex one in 15. Four recurring abnormalities were seen: t(11:14) (q13:q32)in five patients, deletions or translocations involving 7q in seven patients. iso 17q in four patients and translocations involving 2p11 in four patients. The high frequency of clonal chromosome abnormalities in SLVL contrasts with the usually benign clinical course of this disease.
Abnormalities found frequently in patients with chronic lymphocytic leukaemia (CLL) such as trisosmy 12 and deletions or translocations involving 13q14 were each seen in only one patient. No case had the t(14:18) characteristic of follicular lymphoma.
Our findings demonstrate the high frequency of clonal and often complex chromosome abnormalities in SLVL. Although a unique chromosome rearrangement has not been identified, a pattern of four recurrent abnormalities has emerged. Our results suggest that SLVL is distinct on cytogenetic grounds from B-CLL and follicular lymphoma but shows similarity with mantle cell lymphoma, lymphoplasmacytic lymphoma and B-PLL.     

p53 abnormalities in splenic lymphoma with villous lymphocytes

The incidence and role of p53 abnormalities have not been reported in splenic lymphoma with villous lymphocytes (SLVL), the leukemic counterpart of splenic marginal zone lymphoma. Because p53 abnormalities correlate with progressive and refractory disease in cancer and isochromosome 17q has been described in SLVL, a low-grade lymphoma that behaves aggressively in a minority of patients, this study investigated p53 changes by molecular and immunophenotypic methods in samples from 59 patients. The p53 deletion was analyzed by fluorescence in situ hybridization, and p53 protein expression was assessed by immunocytochemistry in 35 of 59 cases and by flow cytometry in 20 of 35 patients. Ten patients (17%) had a monoallelic p53 loss, 3 (9%) of 35 nuclear protein expression by immunocytochemistry, and 2 (10%) of 20 by flow cytometry. Two patients had both deletion and protein expression. Direct sequencing of all p53 exons was used to delineate mutations in 9 of 11 patients with an identified abnormality. Mutations, both compromising p53 DNA binding, were identified in the 2 patients with deletion and protein accumulation. Kaplan-Meier analysis revealed a significantly worse survival for patients with p53 abnormalities. Although p53 abnormalities are infrequent in SLVL, they underlie a more aggressive disease course and poor prognosis. (Blood. 2001;97:3552-3558)     

Splenic lymphoma with circulating villous lymphocytes/splenic marginal-zone lymphoma.

Splenic lymphoma with villous lymphocytes (SLVL) represents a low-grade B-cell non-Hodgkin's lymphoma (NHL) that histologically is indistinguishable from splenic marginal-zone lymphoma (SMZL). Characteristic features of SLVL are splenomegaly, moderate lymphocytosis, nodular and intrasinusoidal pattern of bone marrow infiltration, serum monoclonal band, slow benign course, and response to splenectomy. The diagnosis is made by the morphology of the circulating villous cells and their immunophenotype, which is distinct from that of chronic lymphocytic leukemia (CLL) and hairy-cell leukemia (HCL), diseases with which SLVL may be confused. When treatment is indicated, splenectomy is the treatment of choice, but some patients may require additional chemotherapy to control progression. In those circumstances, fludarabine may be the agent of choice. Despite its unique features, which, compounded, suggest that SLVL is a clinicopathologic entity, there are no specific chromosome abnormalities and problems of differential diagnosis with other B-cell NHLs, chiefly mantle-cell lymphoma (MCL), remain in a minority of patients.     

Multiple M components in two patients with splenic lymphoma with villous lymphocytes

Splenic lymphoma with villous lymphocytes (SLVL) is a rare lymphoproliferative disorder characterized by the presence of typical lymphoid cells with villous projections and monoclonal immunoglobulin (M-Ig) in about 30% of patients. The simultaneous presence of more than one M-Ig in SLVL has not been reported. We present two patients with SLVL, each with three serum M components associated with the presence of rheumatoid factor (RF) and antiphospholipid antibodies (APLA) together with fatal thromboembolic events. Both patients presented with splenomegaly and typical bone marrow cytology with 30–50% infiltration of lymphoid cells that had the characteristics of villous lymphocytes. Immunohistochemistry of bone marrow histology showed CD20++, CD43−/+, CD5−, IgM+, lambda+ and kappa−. In serum, two M-IgMλ components were combined with M-IgGλ in case 1 and with M-IgAλ in case 2. In both cases, M-IgM displayed RF as well as lupus anticoagulant activity and free monoclonal lambda (λ) light chains were present. In addition to M-IgM, in case 1 M-IgG also behaved like an APLA. One patient was splenectomized. Both patients suffered thromboembolic complications and died 3 and 8 months after presentation with signs of massive pulmonary thromboembolism.     

Common clonal origin of lymphocytes and plasma cells in splenic lymphoma with villous lymphocytes

In two-thirds of patients with splenic lymphoma with villous lymphocytes (SLVL) a small amount of M-protein can be detected in association with the presence of plasma cells in the peripheral blood (PB) and/or bone marrow (BM). However, it is not known whether lymphoma cells and plasma cells originate from the same clone. In this report we describe a case of SLVL which was characterized by the presence of marked monoclonal gammopathy (IgG-κ 90 g/l) and increased plasma cells in the BM. In an attempt to elucidate the origin of lymphoma cells and plasma cells, we performed morphological, cytogenetic and molecular studies on PB mononuclear cells (PBMNC) without plasma cells and BMMNC containing 10% plasma cells from this patient.
Immunofluorescence showed that lymphoma cells and plasma cells were positive for cytoplasmic γ heavy and κ light chains. Well-developed endoplasmic reticulum was observed in the cytoplasmic organelles of PBMNC using an electron microscope. The mean IgG concentration in the 3 d supernatant cultures of PBMNC was 374±24μg/l. More than 50% PBMNC differentiated into plasmacytoid cells in 6 d of liquid culture with IL-3 and IL-6. Analysis by two-colour FISH revealed that karyotypic abnormalities of monosomy X and trisomy 17 existed simultaneously in both lymphoma cells and plasma cells. JH gene rearranged bands from PBMNC and BMMNC by Southern blot hybridization were identical, whereas DNAs from PBMNC failed to hybridize with the Cμ probe.
These observations strongly suggest that lymphoma cells and plasma cells originate from the same clone, and that plasma cells, as well as lymphoma cells, which have undergone class switch recombination, could produce IgG type M-protein in this case.     

Fludarabine is effective in the treatment of splenic lymphoma with villous lymphocytes

We report on the use of fludarabine in four patients with splenic lymphoma with villous lymphocytes (SLVL). All four had relapsed after, or failed to respond to, recommended first-line therapies. In each case fludarabine resulted in a complete clinico-haematological response with minimal toxicity, which, in the two patients with long-term follow-up, proved durable. Fludarabine is effective in the treatment of SLVL and should be considered as both a first-line therapeutic option as well as salvage therapy in this condition.     

Successful treatment of splenic lymphoma with villous lymphocytes by rituximab and laparoscopic splenectomy

We report on a case of splenic lymphoma with villous lymphocytes (SLVL) which responded well to rituximab. A 50-year-old man was admitted because of splenomegaly. Abnormal lymphocytes of B cell lineage with moderately basophilic cytoplasm and unevenly distributed villi (villous cells) were found, both in the peripheral blood and bone marrow. CHOP and CHOP-E were performed, without any remarkable change in the size of the spleen. However, after infusion of rituximab (375 mg/m2, once weekly for 2 weeks), there was a marked reduction of the spleen size and the number of circulating villous cells. Splenectomy was performed afterwards, followed by 2 cycles of rituximab infusion. The patient is now followed on an outpatient basis without any sign of relapse.     

The incidence of trisomy 3 in splenic lymphoma with villous lymphocytes: a study by FISH

Splenic lymphoma with villous lymphocytes (SLVL) is a low-grade B-cell lymphoproliferative disorder characterized by splenomegaly and circulating villous lymphocytes. The relationship between SLVL and splenic marginal zone lymphoma (SMZL), a disorder with identical splenic histology to SLVL, is not clear. Previous studies have failed to show a consistent karyotypic abnormality in SLVL whereas trisomy 3 has been reported in patients with SMZL. The presence of trisomy 3 in SMZL and its absence in SLVL has been viewed as evidence that these are different diseases. However, it is possible that the frequency of trisomy 3 in SLVL has been underestimated because previous studies have relied on conventional cytogenetics. We have therefore used interphase fluorescence in situ hybridization (FISH) to re-assess the frequency of trisomy 3 in SLVL. We studied 70 patients, who were stratified into four groups according to the percentage of circulating villous lymphocytes. Trisomy 3 was found overall in 17% of patients. In particular, trisomy 3 was detected in 13% of cases with >50% of villous lymphocytes and which were considered typical of SLVL. In conclusion, we have demonstrated that some patients with SLVL have circulating cells with trisomy 3, which does not support the view that SLVL and SMZL are different diseases on the basis of the incidence of trisomy 3.     

Prognostic features of splenic lymphoma with villous lymphocytes: a report on 129 patients

Splenic lymphoma with villous lymphocytes (SLVL) is a low-grade B-cell lymphoma defined in the World Health Organization classification as the leukaemic form of splenic marginal zone lymphoma. Presenting features and response to therapy have been described, but information on prognostic factors is scanty. Clinical, laboratory and follow-up data were collected on 129 patients with SLVL to determine features predicting disease behaviour and survival. Diagnosis was made on clinical, morphological and immunophenotypic features and, where available, bone marrow and spleen histology. Median age was 69 years (range 39-90 years) and male:female ratio, 0.9. The majority had splenomegaly, but lymphadenopathy and hepatomegaly were rare. Median Hb was 11.8 g/dl, white blood cell count was 16 x 10(9)/l and platelet count was 145 x 10(9)/l; 27% of patients had monoclonal protein in serum and/or urine. While 27% of patients remained untreated, 10% transformed to high-grade lymphoma. Median follow-up was 61 months and median survival was 13 years, with 72% of patients alive at 5 years. Cox regression analysis showed that increasing age, anaemia, thrombocytopenia and lymphocytosis > 16 x 10(9)/l were independent adverse predictors of overall survival. However, only anaemia and lymphocytosis > 16 x 10(9)/l remained highly significant independent prognostic factors when only deaths due to lymphoma were analysed. Splenectomized patients fared better than those receiving chemotherapy only (P = 0.001 for SLVL deaths). We conclude that SLVL is mainly a disease of the elderly with a relatively benign course but, when treatment is required, splenectomy is beneficial.     

The immunophenotype of splenic lymphoma with villous lymphocytes and its relevance to the differential diagnosis with other B-cell disorders

Splenic lymphoma with villous lymphocytes (SLVL) is a low-grade disorder that regularly presents with peripheral blood involvement. We describe the immunophenotype of the circulating cells from 100 SLVL patients whose disease has been characterized on clinical, morphologic, and histologic grounds. Cells from all cases expressed B-cell antigens (CD19 and CD37) and/or HLA-Dr and showed light chain restriction (kappa/lambda: 1.5/1) with moderate to strong intensity of membrane Ig staining. Cells from most cases (> 80%) were CD24+, FMC7+, and expressed strongly membrane CD22. The monoclonal antibodies CD10, CD23, and CD38 were positive in one-third of the cases; CD11c in 47%; and CD25 in 25% of cases. A minority of cases (< 20%) were positive with HC2, B-ly-7, and CD5. However, none of the 19 CD5+ cases had the phenotype characteristic of chronic lymphocytic leukemia (CD5+, CD23+, FMC7-, weak surface Ig and membrane CD22). None of the 17 CD25+ cases had the immunophenotype typical of hairy cell leukemia (CD25+, CD11c+, HC2+, B-ly-7+). HC2 and B-ly-7 were the most useful reagents to distinguish SLVL from hairy cell leukemia. Our findings demonstrate that SLVL has a distinct immunologic profile and that monoclonal antibodies are important for the differential diagnosis between this disease and other B-lymphoproliferative disorders with which SLVL can be confused.     

Dramatic efficacy of fludarabine in the treatment of an aggressive case of splenic lymphoma with villous lymphocytes

Splenic lymphoma with villous lymphocytes (SLVL) is an indolent lymphoproliferative disorder of mature B lymphocytes. Splenectomy is primarily recommended for treating this disease, and splenic irradiation or alkylating agents may be effective; however, frequent recurrence is observed after these therapies. We report here an unusual case of SLVL in which the degree of splenomegaly and the serum IgM level increased rapidly. Although the effects of splenic irradiation and combination chemotherapy were both unsatisfactory and transient, complete remission lasting for more than 15 months was achieved after two courses of treatment with low-dose fludarabine (15 mg m(-2) daily for 3 d). The present case indicates that treatment with fludarabine is effective for SLVL and recommended as the first-line therapy for elderly patients and those with an aggressive form of the disease.     

Blastic transformation of splenic lymphoma with villous lymphocytes after a well-controlled chronic phase of more than 10 years

A 30-year-old Japanese man with splenomegaly and lymphocytosis was examined in 1985. Blood analysis revealed that some of the lymphocytes had short-surface villi with polar distribution. The cells showed Ig lambda+, CD5+, CD11c+, CD19+, CD22+, CD23+, CD24+, FMC7+ phenotype. A small M peak was detected in the serum. Splenic lymphoma with villous lymphocytes (SLVL) was diagnosed on the basis of these findings. Remission was induced and was maintained with low-dose chlorambucil for more than 10 years. In 1996, the patient developed splenomegaly and lymphadenopathy with "B" symptoms and a high serum lactase dehydrogenase (LDH) level. Large blastoid cells with prominent nucleoli were observed in the bone marrow; later, a small number appeared in the peripheral blood. The bone marrow cells showed a complex chromosomal abnormality involving del(7)(q32). Southern blot analysis of immunoglobulin gene rearrangements in SLVL cells that had been cryopreserved in 1986 and of bone marrow cells in 1996 showed 2 rearranged bands in each cell sample; 1 band showed identical sizes in the 2 samples, and the other showed different sizes. These findings suggest that the blastoid cells were derived from SLVL cells through transformation. After this transformation, the disease followed a highly aggressive course. Various chemotherapeutic agents had little effect, and the patient died 3 months later.     

Relationship between hairy cell leukemia variant and splenic lymphoma with villous lymphocytes: Presentation of a new concept

An unusual case of low-grade B-cell lymphoproliferative disorder with peripheral lymphocytosis and splenomegaly followed for 4 1/2 years is reported. During this period, the phenotype of the tumor cells in the blood changed from that of hairy cell leukemia (HCL)/chronic lymphocytic leukemia (CLL) to HCL/prolymphocytic leukemia (PLL), to PLL. The lymphoid population in the blood showed a mixture of hairy cells, villous lymphocytes, small lymphocytes, and prolymphocytes, corresponding to the phenotypes at various stages. Although relatively specific markers for CLL, HCL, and PLL, such as CD5, CD11c, CD22, CD25, and FMC-7, were positive at various stages, all these markers have also been demonstrated in a large study series of splenic lymphoma with villous lymphocytes (SLVL). In addition, the histologic pattern of the bone marrow biopsy and splenectomy specimen were not typical for HCL. This case can therefore be classified either as HCL variant or as SLVL. As SLVL assumes various cytologic and histologic patterns, which overlap with different lymphoproliferative disorders, especially HCL variants, this entity appears to represent a heterogeneous group of lymphomas/leukemias that may evolve into each other. The absence of activation of c-myc and bcl-2 oncogenes as well as mutation of p53 tumor suppressor gene, together with the presence of only one single rearranged band for both heavy chain and κ light chain genes in our case suggest that these morphologically different lymphoid tumors may belong to the same family. © 1996 Wiley-Liss, Inc.     

Splenic lymphoma with villous lymphocytes expressing chromosomal abnormalities]

An 88-year-old Japanese woman with splenomegaly, but without lymphadenopathy, was admitted because of epigastric distress. Laboratory data disclosed an RBC of 310 x 10(4)/microliter, Hb of 10.1 g/dl, Ht of 30.6%, Plt count of 9.8 x 10(4)/microliter, and WBC of 4,470/microliter with 38% abnormal lymphocytes. Peripheral blood films revealed lymphocytes with thin, short cytoplasmic villi, condensed nuclear chromatin, and small nucleoli. The lymphocytes stained negative for tartrate-resistant acid phosphatase. Also, immunophenotyping was positive for expression of the cell surface markers CD19, CD20, IgG, kappa and HLA-DR, but not for CD5, CD10, CD11c, CD23, CD25, CD38, or CD103 antigens. Chromosomal analysis of peripheral blood cells disclosed the 46, XX, del(7), (q32) aberration. A splenectomy was performed simultaneously with partial colon resection because of a mucinous carcinoma found in the transverse colon. Histologic examination of resected spleen tissues revealed a distinctive pattern of white pulp infiltration by lymphoma cells. The histologic findings and clinical data were consistent with the features of splenic lymphoma with circulating villous lymphocytes. Our patient exhibited a relatively benign clinical course, and was being followed on an outpatient basis with no additional therapy.