Autopsy case of lymphoplasmacytic lymphoma with a large submucosal tumor in the stomach

An autopsy case of lymphoplasmacytic lymphoma with a large submucosal tumor in the stomach is presented. The patient was a 77-year-old woman with gastric lymphoma associated with Waldenstrom's macroglobulinemia of IgM-lambda type. Diagnosis was initially mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach, because gastric biopsy specimens showed epitheliotropic proliferation (lymphoepithelial lesion) of the lymphoma cells. Postmortem examination revealed a large gastric lymphoma with metastatic foci in the esophagus, larynx, trachea, lungs, spleen and lymph nodes. The bone marrow was also involved. Lymphoma cells consisted of small lymphocytoid cells occasionally admixed with blast-like large cells and a large number of plasmacytoid or plasma cells. Centrocyte-like cells were not found. Lymphoepithelial lesions were not conspicuous in autopsy specimens. Immunohistochemically, lymphoma cells reacted with CD20, CD45, CD79a, anti-IgM, anti-lambda protein and anti-BCL-2, but not with CD5, CD10, CD23 or CD38. Based on these findings, the revised diagnosis of the present case was lymphoplasmacytic lymphoma, and it highlighted the differential diagnostic problem from marginal zone B-cell lymphoma of MALT type.     

Diffuse large B-cell lymphoma with anaplastic features and focal low-grade mucosa-associated lymphoid tissue lymphoma component of the stomach

We describe an 83-year-old man diagnosed as having diffuse, large B-cell lymphoma with anaplastic features and CD30 expression of the stomach. Focally, the tumor showed typical low-grade mucosa-associated lymphoid tissue lymphoma. We are not aware of a previous report on the transformation of low-grade gastric lymphoma of mucosa-associated lymphoid tissue type into an "anaplastic," large B-cell tumor.     

”Composite” lymphoma, lymphoplasmacytoid and diffuse large B-cell lymphoma of the spleen: molecular-genetic evidence of a common clonal origin

We describe here the first well-characterized case of ”composite” lymphoma of the spleen in which the two components were a low-grade and a high-grade B-cell non-Hodgkin’s lymphomas. The patient was an elderly man with prominent splenomegaly and multiple hypoechogenic lesions of the spleen. A splenectomy was performed, and the macroscopic and histological findings showed the simultaneous presence of a ”low-grade” B-cell lymphoma, lymphoplasmacytoid (immunocytoma) and a ”high-grade” B-cell lymphoma (immunoblastic), which were spatially separated. The two lesions expressed the same immunoglobulin light chain (lambda), but the Southern blot analysis showed different patterns of immunoglobulin heavy chain (IgH) clonal rearrangement. PCR analysis followed by direct sequencing of the IgH-amplified rearrangement products provided molecular-genetic evidence that the two components of the composite lymphoma had the same clonal origin. Since both EBV LMP-1 and p53 were negative by immunohistochemistry, it is unlikely that EBV and p53 were involved in the neoplastic progression in this case. PCR analysis and direct sequencing of IgH-amplified rearrangement products are useful tools to investigate clonality in cases in which Southern blot analysis cannot be performed or does not provide conclusive findings. Received: 22 February 1999 / Accepted:30 April 1999     

Marginal zone lymphoma associated with Sj?gren's syndrome and hepatitis C virus infection]

A 64-year-old female was admitted in May 1997, because of salivary gland swelling. Histology of the right parotid gland revealed malignant lymphoma, diffuse medium-sized B-cell type, and she was treated with local radiotherapy and chemotherapy. She was rehospitalized in April 1998, because of recurrence of lymphoma in the stomach and the sigmoid colon. She had splenomegaly and lymphadenopathy (neck and inguinal). Laboratory findings revealed marked elevation of rheumatoid factor and RNA of hepatitis C virus. A diagnosis of Sjogren's syndrome was made by dryness and the histological findings of labial biopsy. Marginal zone B-cell lymphoma mainly consisted of centrocyte-like cells and lymphoepithelial lesions, and CD 20 and IgM-kappa were positive with immunohistochemical staining. Lymphoma involved the gut and spleen. We discuss the correlation of malignant lymphoma with Sjogren's syndrome and HCV infection.     

Synchronous adenocarcinoma and low grade B-cell lymphoma of mucosa associated lymphoid tissue (MALT) of the stomach

We describe nine cases of gastric adenocarcinoma (six intestinal and three diffuse type) occurring in the stomach synchronously with primary low grade B-cell lymphoma of mucosa associated lymphoid tissue. In four cases the two neoplasms were admixed to form collision tumours. Where collision was present between lymphoma and adenocarcinoma of intestinal type no lymphoepithelial lesions were seen involving neoplastic glands. Helicobacter pylori-like organisms were seen in seven cases (78%) which is consistent with an aetiological role for this organism in both tumours in the stomach.     

Malignant lymphoma of the spleen in Japan: A clinicopathological analysis of 115 cases

Primary splenic lymphoma is rare, but malignant lymphoma often produces a lesion in the spleen as part of systemic disease. The frequency of splenic malignant lymphoma in Japan is unknown. We classified 184 specimens of the spleen according to the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues, 4th edition (2008). Of the 184 specimens, 115 were determined to be lymphoid neoplasm (62.5%). The most common subtype of lymphoid neoplasm was diffuse large B-cell lymphoma (DLBCL) (46 cases), followed by splenic marginal zone lymphoma (SMZL) (28 cases), follicular lymphoma (11 cases), splenic B-cell lymphoma, unclassifiable (SBL-U) (6 cases) and peripheral T-cell lymphoma, not otherwise specified (4 cases). In the SBL-U subtype, 5 of 6 cases were splenic diffuse red pulp small B-cell lymphoma, and one case was the hairy cell leukemia variant. Analysis of clinical features revealed that patients with DLBCL had a higher age, high lactate dehydrogenase and tumor formation in the spleen. On the other hand, it was found that patients with SMZL had splenomegaly but no discrete tumor formation. Most of the patients with SBL-U presented with thrombocytopenia, bone marrow involvement, and advanced stage. Our study revealed the frequency and clinical features of splenic malignant lymphoma in Japan.     

Lymphoma of the small intestine

A series of eight small intestine lymphomas comprised two cases of follicular lymphoma (FL), one anaplastic large cell lymphoma (ALCL) ALK negative, and five cases of diffuse large B-cell lymphoma. The lymphomas were diagnosed by routine hematoxylin-eosin staining, immunohistochemistry and the FISH method for translocation t(14;18). Immunohistochemistry revealed that the diffuse large B-cell lymphomas were of the non-germinal center type (non GC-DLBCL). In most cases, the tumors formed solid well-circumscribed nodules or resulted in diffuse infiltration of the intestinal wall. In one case of follicular lymphoma, microscopic foci of tumor were found in the intestinal mucosa which spread far from the primary nodule and probably beyond the resection border. It is difficult to ascertain whether this phenomenon represents colonization of pre-existing non-neoplastic follicles by lymphoma or spreading of the tumor within the same tissue. In this case, surgical removal of the lymphoma is problematic.     

Role of ultrasound-guided core biopsy in the evaluation of spleen pathology

Core biopsy has not traditionally been recommended in the study of spleen nodules due to the supposed fragility of this organ leading to a high risk of post-core biopsy complications. A total of 13 patients who presented solid spleen nodules, diffuse splenomegaly, or both on imaging studies (CT, MR, US) were biopsied under ultrasound control with 18G BioPince needles. Cytological (imprints and cytocentrifugates) and histological material were obtained for diagnosis in every case. Malignant lymphomas were the most commonly found pathology (four diffuse large B-cell lymphomas, two follicular lymphomas, one Hodgkin's disease, one B-cell lymphoma, NOS). In addition, there was one littoral-cell angioma, one well-differentiated neuroendocrine carcinoma, metastatic, and one haemangioma. The remaining two cases showed congestive features, and supposed spleen involvement by lymphoma in one of them was ruled out. On follow up, there were no complications related to the core biopsy. Splenectomy was performed in six cases, two diagnostic and four therapeutic. We conclude that core biopsy is a safe and efficient method in the diagnosis of spleen nodules that could be considered in the routine diagnostic algorithm of these lesions.     

Follicular dendritic cell tumor of the spleen associated with diffuse large B-cell lymphoma

We report the case of a 50-year-old woman with an isolated large mass of the lower pole of the spleen. Splenectomy was performed and revealed a follicular dendritic cell (FDC) tumor associated with diffuse large cell lymphoma. Dendritic cells were CD21(+), CD35(+), CNA42(+), CD20(-), and Epstein-Barr virus (EBV)(+). They contained a clonal EBV genome as shown by polymerase chain reaction analysis of the LMP-1 gene polymorphism. Interestingly, the lymphoma cells were intermingled with the neoplastic FDCs and displayed a germinal center cell phenotype (CD20(+), CD10(+), Bcl2(+), and EBV(-)). Double staining confirmed that EBV was restricted to the FDCs. Clinical, radiologic, and pathologic staging showed no other lymphoma localization. To the best of our knowledge, this association has never been reported. Based on the well-established role of FDCs in B-cell survival and proliferation, this observation suggests that the FDC tumor represented a favorable microenvironment for lymphoma cells with germinal center phenotype.     

Malignant lymphomas of the nasal cavity and Waldeyer's ring--clinicopathologic and immunohistochemical study.

The clinicopathologic and immunohistochemical finding of 10 cases of nasal non-Hodgkin's lymphoma (NHL) and 23 cases of Waldeyer's ring NHL were studied. Immunohistochemically, nasal NHL expressed T-cell markers exclusively, whereas the NHL of Waldeyer's ring were of both T-cell (56.5%) and B-cell lineages (43.5%). Angioinvasiveness by tumor cells was exclusively noted in the T-lineage lymphomas. Epithelial hyperplasia, epitheliotropism by tumor cells, and extensive invasion of adjacent normal tissue were more prominent in T-cell lymphomas than in B-cell lymphomas. T-lineage lymphomas showed distant extranodal spread pattern involving the skin, soft tissue, stomach, spleen, and the liver, whereas B-lineage lymphomas tended to localize in the lymph nodes. The survival rate of Nasal NHL was similar to that of Waldeyer's ring NHL. Although not statistically significant because of small sample numbers, immunophenotype, histologic groups of monomorphic lymphoma, and stage had prognostic importance. In general, T-lineage lymphomas presented with a higher stage than B-lineage lymphomas (p < 0.05)-and overall survival was poor. Stage I disease showed a much more favorable prognosis than stage II disease. Monomorphic lymphomas had a shorter survival than polymorphic reticulosis (PR) or lymphomas with features of PR. This result in conjunction with the morphologic transition between them suggested that monomorphic lymphoma may represent the most advanced stage in the spectrum of PR, lymphoma with features of PR, and monomorphic lymphoma.     

Primary T-cell non-Hodgkin's malignant lymphoma of the appendix

A case of primary T-cell lymphoma of the appendix in an 84-year-old female was reported. Appendectomy was performed as a result of the clinical diagnosis of acute appendicitis, due to the rebound tenderness of McBurney's point and thickness of the appendix wall as determined from ultra echo sonograph. Grossly, the surgical resected appendix did not have a dominant inflammatory appearance, therefore a tumor was suspected. Microscopic examination showed diffused proliferation of large and medium size lymphoma cells. Immunohistochemical examination further revealed that the lymphoma cells were positive for T-cell markers. To ensure this was a T-cell lymphoma, molecular examination was performed using paraffin-embedded tissue sections, since T-cell lymphoma of the appendix is extremely rare. Polymerase chain reaction (PCR) single-strand conformation polymorphism (SSCP) analysis demonstrated monoclonal T-cell receptor gene rearrangement. T-cell-rich B-cell lymphoma was excluded. To our knowledge, this is the first reported case of primary T-cell lymphoma of the appendix. PCR-SSCP analysis in paraffin-embedded tissue section was very useful in the diagnosis of lymphoma cell monoclonality.     

Discordant lymphoma: MALT lymphoma of the stomach and follicular lymphoma of the parotid gland

More than one histological type of malignant lymphoma can occur simultaneously in an individual. The entity is classified as either composite or discordant lymphoma. Both types of lymphoma, particularly discordant lymphoma comprised of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue lymphoma (MALT-L) and follicular lymphoma (FL), are rare. We report a case of discordant lymphoma comprising MALT-L in the stomach and FL in the parotid gland. The patient was a 50-year-old Japanese woman who visited the University Hospital of Showa (Tokyo, Japan) because a barium study showed erosive gastric lesions. A gastro-intestinal endoscopy was performed 2 months after the barium study, which showed irregular erosions throughout the stomach body. A gastric biopsy showed MALT-L, and Helicobacter pylori (H. pylori) infection was confirmed. The patient had noticed a painless and elastic hard tumor mass of about 2 cm in diameter in the area of the left parotid gland 6 months before the barium study. We removed the parotid gland tumor and diagnosed it as FL 6 months after the barium study. We were able to diagnose the MALT-L and FL by morphological, immunohistochemical and molecular analyses of paraffin-embedded sections. This appears to be the first reported case of MALT-L and FL occurring together as a discordant lymphoma.     

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma without mediastinal disease: mimicking nodular sclerosis classical Hodgkin lymphoma

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma (BCLu-DLBCL/CHL), also known as gray-zone lymphoma, has overlapping clinical and biological characteristics of both diffuse large B-cell lymphoma and classical Hodgkin lymphoma (CHL). These lymphomas are typically associated with mediastinal disease, and extranodal involvement is rare. In the present report, we describe a case of a 78-year-old woman with BCLu-DLBCL/CHL found to have extranodal lesions and no evidence of mediastinal disease. Although biopsy specimens were histologically similar to nodular sclerosis CHL, the tumor cells were positive for CD30 and mature B-cell markers, such as CD20, CD79a, PAX5, BOB.1, and OCT-2, but negative for CD15. Furthermore, the patient had extranodal lesions and an increased level of soluble IL-2 receptor. These findings are unusual in CHL. Therefore, we diagnosed the patient with BCLu-DLBCL/CHL. She received adriamycin, bleomycin, vincristine, and dacarbazine therapy and exhibited partial response. Some cases without mediastinal disease, such as our case, have been reported; however, these cases are rare and further studies are required.     

Full clinical recovery after topical acyclovir treatment of Epstein-Barr virus associated cutaneous B-cell lymphoma in patient with mycosis fungoides

Primary cutaneous T- and B-cell lymphomas are a heterogeneous group of diseases with varied clinical presentations and prognosis. The use of new molecular, histological, and clinical criteria has improved their recognition. Cutaneous B-cell and T-cell lymphomas are seldom found together in the same patient. Here we report a rare case of mycosis fungoides variant of a cutaneous T-cell lymphoma (CTCL) which later developed Epstein-Barr virus (EBV) associated cutaneous B-cell lymphoproliferative disorder. The patient initially presented with generalized erythroderma, extensive plaques, and axillary lymphadenopathy. Histopathology and immunophenotyping of her tumor from the right breast nodule revealed a T-cell lymphoma consistent with mycosis fungoides. She was initially treated with pentostatin, followed by topical mechlorethamine and topical steroids. After progression of her mycosis fungoides with worsening diffuse skin lesions on this regimen, her treatments were changed to oral bexarotene with an initial partial response followed by stable disease. Three years from her initial presentation, she developed ulcerated cauliflower-like nodules on her forehead. Biopsy of these lesions revealed EBV-positive large- and medium-sized pleomorphic B-cells consistent with EBV-driven B-cell lymphoproliferative disorder. She was treated with topical acyclovir cream on the involved skin areas while continuing with oral bexarotene for mycosis fungoides. Skin lesions gradually diminished and totally disappeared after four weeks of topical acyclovir treatment. Bexarotene treatment was continued for another year until the mycosis fungoides progressed and became wide spread causing her death four and a half years after the initial diagnosis. The coexistence of two cutaneous non-Hodgkin lymphomas of different lineage in the same patient and the complete clinical response of EBV-related B-cell cutaneous component to topical acyclovir makes this rare case particularly interesting.     

Primary gastrointestinal B-cell lymphoma. A clincopathological and immunohistochemical study of 61 cases with an evaluation of prognostic parameters.

We hereby present a retrospective clinicopathological and immunohistochemical study of surgically resected primary gastrointestinal (GI) lymphoma with an analysis of parameters of potential prognostic relevance. From a larger series of 144 cases of primary GI lymphomas, we chose 61 cases with sufficient clinical follow-up (mean 60, range 1-219 months), classified either as extranodal marginal zone B-cell lymphoma of MALT type (MALT lymphoma) or diffuse large B-cell lymphoma (DLBCL), after having excluded other subtypes. In addition to conventional clinical and morphological parameters, the expression levels of Ki-67 (MIB-1), bcl-2 and p53 were evaluated for prognostic significance. Twenty-one (34.4%) cases were classified as pure low grade marginal zone B-cell lymphoma of MALT type, 12 (19.7%) cases as low grade MALT lymphoma with a high grade component (mixed type), and 28 (45.9%) cases as primary extranodal DLBCL. Most of the lymphomas (53/61; 86.9%) were localized in the stomach, 3 (4.9%) in the small bowel, 3 (4.9%) multifocal in both stomach and small intestine and 2 (3.3%) in the large bowel. MIB-1 expression in more than 30% of tumor cells was detected in 42 (68.6%), bcl-2 expression in 20 (32.8%) and p53 accumulation in more than 10% of neoplastic cells in 16 (26.2%) lymphomas. Both high Ki-67 expression and p53 accumulation were more prevalent in the DLBCL. 30 (49%) patients showed lymph node involvement at surgery, 14 (23%) patients suffered tumor recurrence, and 24 (38.5%) died during the follow-up period. Tumor recurrence occurred primarily in patients who had presented lymph node involvement (9/14, 64.3%). The 5-year survival rate was 66.1% for all patients. Important prognostic factors for overall survival were tumor stage (p < .004) and p53 accumulation (p < .05) in univariate analysis, and tumor stage in multivariate analysis (p < .001). Although p53 accumulation did not reach statistical significance in our small study group, it may be both important in the transformation of low grade MALT lymphoma and an indicator for aggressive behavior in high grade tumors.     

Diffuse large B-cell lymphoma initially manifesting in the bone marrow

We histologically and immunohistochemically studied 37 cases of diffuse large B-cell lymphoma (DLBCL) initially manifesting in the bone marrow (BM). We also compared these cases with the Asian variant of intravascular large B-cell lymphoma (AIVL). Histologically, the neoplastic cells of the BM mostly had large and round nuclei and formed clusters. Immunohistochemically, all cases were positive for B-cell markers. Factor VIII staining revealed neoplastic cells within the sinusoids of BM in 8 cases; however, these cells accounted for fewer than 20% of the overall neoplastic cells. In several cases, the neoplastic cells infiltrated liver, spleen, kidneys, lungs, stomach, and adrenal glands with a mainly leukemic and infrequently intravascular pattern. Although our cases share some clinical features with AIVL, we consider DLBCL initially manifesting in the BM to be a unique entity because the neoplastic cells proliferate mainly in BM, with infrequent involvement of the sinusoids and occasional leukemic infiltration in various organs.     

Natural killer cell subsets and natural killer-like T-cell populations in benign and neoplastic B-cell proliferations vary based on clinicopathologic features

Microenvironmental factors play a critical role in B-cell lymphomas. Most studies emphasize the role of lymphoma-infiltrating T-cells and macrophages, with few studies on natural killer cells. Natural killer cells include a less mature (CD56(bright)/CD16-) subset that is more common in lymph nodes and a more mature (CD56(dim)/CD16+) subset that is more numerous in peripheral blood. Therefore, the proportions of natural killer cells, natural killer subsets, and natural killer-like T-cells (CD3+, CD56+, and/or CD16/57+) were determined by flow cytometry in 150 cases of tissue-based B-cell non-Hodgkin lymphoma and 89 nonneoplastic tissue biopsies. Results were correlated with the clinicopathologic findings. A higher percentage of natural killer cells was found in nonneoplastic spleen versus other nonneoplastic tissue (P < .001), in splenic-based B-cell non-Hodgkin lymphoma versus other B-cell non-Hodgkin lymphoma (P < .01), and in stage II to IV diffuse large B-cell lymphoma versus stage I diffuse large B-cell lymphoma (n = 19, P = .02). The more mature natural killer subset was increased in benign spleen (P < .001) and nonsplenic B-cell non-Hodgkin lymphoma (P < .01) versus nonsplenic, nonneoplastic tissue; in diffuse large B-cell lymphoma versus other B-cell non-Hodgkin lymphoma (P < .001); and in follicular lymphoma with an intermediate follicular lymphoma international prognostic index score (n = 17, P = .04). A higher proportion of natural killer-like T-cells was seen in diffuse large B-cell lymphoma versus other B-cell non-Hodgkin lymphoma (P = .001), whereas chronic lymphocytic leukemia/small lymphocytic lymphoma contained fewer natural killer-like T-cells (P < .001). The proportions of natural killer cells, natural killer subsets, and natural killer-like T-cells vary with tissue site, type of B-cell non-Hodgkin lymphoma, and clinical stage in diffuse large B-cell lymphoma and follicular lymphoma. A higher proportion of CD56(dim)/CD16/57+ natural killer cells is found in spleen, in more aggressive B-cell non-Hodgkin lymphoma, and in follicular lymphoma with an intermediate follicular lymphoma international prognostic index score. This may be of importance with increasing therapeutic use of immunomodulatory agents.     

Spontaneous regression of primary breast lymphoma

Described herein is a case of primary breast lymphoma (PBL) that underwent spontaneous regression (SR). A 71-year-old woman visited hospital because of the rapid growth of a tumor in her left breast. On imaging, including magnetic resonance imaging (MRI), a discrete solid nodule was detected, which suggested malignant tumor. Histology of the following core needle biopsy (CNB) specimen indicated diffuse large B-cell lymphoma (DLBCL). The patient had no past history of lymphoma and there was no evidence of systemic lymph nodes enlargement. After CNB, however, the patient noticed that her breast nodule gradually decreased in size without any specific treatment. Subsequent MRI showed an ill-defined nodular area suggesting a regressing tumor. Excisional biopsy indicated fibrotic mammary tissue devoid of large neoplastic lymphoid cells. The patient has remained well without evidence of recurrent lymphoma more than 18 months after her original diagnosis. This case is considered to be unique in a PBL showing SR, probably induced by an intervention of CNB and histologically confirmed on sequential examinations in addition to illustrative before-and-after imaging. To the best of the authors' knowledge no other PBL of DLBCL has been reported as undergoing a complete SR in the English-language literature.     

Overview of 2008 WHO Classification of Malignant Lymphoma

Lymphoma classification is now evolving. The 4th edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues was published in 2008, regarded as a revised and updated version of the 2001 3rd edition; an effort that involved 138 authors from 22 countries and two clinical advisory committees comprising 62 clinical specialists with expertise in lymphoid and myeloid disorders. New aspects of the 2008 WHO classification can be briefly summarized as follows: 1) a greater recognition of "early" lesions, i.e., an incipient neoplasm, e.g., in situ follicular lymphoma, has been incorporated; 2) age was highlighted as a defining feature of some neoplasms, e.g., EBV+ diffuse large B-cell lymphoma of the elderly, pediatric follicular lymphoma, and EBV+ T-cell lymphoproliferative diseases of childhood; 3) anatomical sites were noted as having an important impact on disease definitions; and 4) newly recognized borderline categories were listed on the basis of their biological overlap between diffuse large B-cell lymphoma and Burkitt lymphoma or classical Hodgkin lymphoma.     

Growth and dissemination of a newly-established murine B-cell lymphoma cell line is inhibited by multimeric YIGSR peptide

B-cell lymphoma frequently shows simultaneous dissemination to multiple organs. It also occasionally involves bone and causes osteolytic lesions. To study the mechanisms responsible for this capacity of lymphoma cells to grow in different tissue microenvironments and search for effective therapeutic interventions for this hema-tological malignancy, we established a new murine B-cell lymphoma cell line named MH-95. The tumor disseminated to multiple organs including the lung, liver, kidney, spleen and lymph nodes within 2 weeks after subcutaneous inoculation in nude mice. In addition, the tumor also grew in bone and caused osteoclastic osteolytic lesions. Thus, this tumor model mimics the behavior in many ways of B-cell lymphoma in humans. We studied the role of laminin, a major component of the basement membrane, in this model, since although it has been implicated in solid tumor metastasis, little is known about the involvement of laminin in the growth of B-cell lymphoma in bone and other organs. Immunohistochemical examination showed strong laminin expression in the stroma of the primary subcutaneous tumor and tumors in the bone and other organs. Systemic administration of the antagonistic laminin peptide YIGSR decreased primary tumor growth and tumor cell deposit in the bone, liver and kidney. In addition, the peptide also decreased apparent neovascu-larization in the tumor, suggesting that the peptide suppressed angiogenesis presumably due to inhibition of laminin binding to its receptors. These results demonstrate that the MH-95 B-cell lymphoma cells express laminin and suggest that laminin plays a critical role in the growth and simultaneous dissemination of tumor cells to multiple organs, similar to what has been described in solid tumors. The results also suggest that suppression of angiogenesis through interfering with laminin actions may be a useful adjuvant therapy for B-cell lymphoma. ©Lippincott Williams & Wilkins