The blood microvasculature in T-cell lymphomas. A morphological, ultrastructural and immunohistochemical study

Angiogenesis extent and macrophage density increase simultaneously with pathological progression in B-cell non-Hodgkin's lymphomas

Node biopsies of 30 benign lymphadenopathies and 71 B-cell non-Hodgkin's lymphomas (B-NHLs) were investigated for microvessel and macrophage counts using immunohistochemistry and morphometric analysis. Both counts were significantly higher in B-NHL. Moreover, when these were grouped into low-grade and high-grade lymphomas, according to the Kiel classification and Working Formulation (WF), statistically significant higher counts were found in the high-grade tumours. Immunohistochemistry and electron microscopy revealed a close spatial association between microvessels and macrophages. Overall, the results suggest that, in analogy to what has already been shown in solid tumours, angiogenesis occurring in B-NHLs increases with tumour progression, and that macrophages promote the induction of angiogenesis via the release of their angiogenic factors.

Do mast cells help to induce angiogenesis in B-cell non-Hodgkin's lymphomas?

Morphological and morphometric data showing a higher number of mast cells (MCs) in the stroma of B-cell non-Hodgkin's lymphomas (B-NHL) than in benign lymphadenopathies are presented in support of the suggestion that angiogenesis during the progression of B-NHL may be partly mediated by angiogenic factors in their secretory granules.

Human lymphoblastoid cells produce extracellular matrix-degrading enzymes and induce endothelial cell proliferation, migration, morphogenesis, and angiogenesis

Human lymphoproliferative diseases can be hypothesized to invade locally and to metastatize via mechanisms similar to those developed by a variety of solid tumors, i.e., the secretion of extracellular matrix-degrading enzymes and stimulation of angiogenesis. To assess this hypothesis, Namalwa, Raji, and Daudi cell lines (Burkitt's lymphoma), LIK and SB cell lines (B-cell lymphoblastic leukemia), CEM and Jurkat cell lines (T-cell lymphoblastic leukemia), and U266 cell line (multiple myeloma) were evaluated for their capacity to produce matrix metalloproteinase-2 and -9, and urokinase-type plasminogen activator. These cell lines were also assessed for their ability: (1) to produce the angiogenic basic fibroblast growth factor and vascular endothelial growth factor; (2) to induce an angiogenic phenotype in cultured endothelial cells, represented by cell proliferation, chemotaxis, and morphogenesis; (3) to stimulate angiogenesis in different in vivo experimental models. All cell lines expressed the mRNA for one or both metalloproteinases. Namalwa, Raji, LIK, SB, and U266 cells secreted the active form of both metalloproteinases, while Daudi, CEM, and Jurkat cells produced metalloproteinase-2 but not-9. In contrast, urokinase-type plasminogen activator was secreted only by SB cells. While Raji, LIK, SB, CEM, and Jurkat cells secreted both basic fibroblast growth factor and vascular endothelial growth factor, Daudi and U266 cells produced only the former, and Namalwa cells only the latter. Accordingly, the conditioned medium of all cell lines stimulated cell proliferation and/or chemotaxis in cultured endothelial cells, with the exception of that of Namalwa cells which was ineffective. The conditioned medium of CEM and Jurkat cells induced morphogenesis in cultured endothelial cells grown on a reconstituted basement membrane (Matrigel). Lastly, Namalwa, Raji, LIK, SB, U266, CEM, and Jurkat cells induced angiogenesis and mononuclear cell recruitment in the murine Matrigel sponge model and in a chick embryo chorioallantoic membrane assay. The extent of angiogenesis in both models was strictly correlated with the density of the mononuclear cell infiltrate. The results indicate that human lymphoproliferative disease cells possess both local and remote invasive ability via the secretion of matrix-degrading enzymes and the induction of angiogenesis which is fostered by host inflammatory cells and by an intervening ensemble of angiogenic factors.

Progression of mycosis fungoides is associated with changes in angiogenesis and expression of the matrix metalloproteinases 2 and 9

Changes in angiogenesis and expression of extracellular matrix-degrading enzymes have been substantiated during progression of solid tumours, whereas information on haematological tumours remains circumstantial. In this study, 57 biopsies of mycosis fungoides (MF), a haematological tumour of T-cell lineage, were investigated immunohistochemically for the extent of angiogenesis, and by in situ hybridisation for the expression of matrix metalloproteinases 2 (MMP-2, collagenase A) and 9 (MMP-9, collagenase B). The biopsies we grouped according to the stage of progression: patch-->plaque-->nodular (most advanced). The extent of angiogenesis, as microvessel area, of MF lesions as a whole was significantly higher than that of normal uninjured skin, used as a control. When the stages of MF progression were compared, the values of MF patch stage overlapped that of control skin, while values were significantly higher in the plaque stage and even higher in the nodular stage. In these stages, microvessels were widely scattered in the tumour tissue, in close association with tumour cells, and they frequently displayed arborisation and microaneurysmatic dilation. In contrast, in the patch stage microvessels were irregularly distributed around the tumour aggregates, and arborisation or dilated structures were only rarely seen. The expression of MMP-2 and MMP-9 mRNAs underwent significant upregulation in relation to advancing stage. Indeed, the upstaging was significantly associated with higher proportions of lesions positive for each mRNA or for both, and with lesions with the greatest intensity of expression for each mRNA. Besides tumour cells, the MMP-2 mRNA was expressed by microvascular endothelial cells of intratumour and peri-tumour vessels, and by fibroblasts which were especially abundant in the stroma adjacent to the tumour nodules. The MMP-9 mRNA was found to be present in a subset of tissue macrophages which were more frequently located in close vicinity to the tumour nodules. In contrast, in control skin, a weak positivity for the MMP-2 mRNA in very few microvascular endothelial cells and no signal for the MMP-9 mRNA were observed. These in situ data suggest that angiogenesis and degradation of the extracellular matrix occur simultaneously during MF progression. They imply that interaction between tumour cells and their microvasculature are all the more likely to occur during progression, occasionally with the contribution of tumour-associated stromal cells.

Focal hepatic lymphoma: magnetic resonance demonstration using current techniques including gadolinium enhancement

This study demonstrates the appearance of focal hepatic lymphoma using current magnetic resonance techniques including gadolinium enhancement. Fifteen patients with hepatic lymphoma were imaged at 1.5T. T1-weighted, T2-weighted, immediate, and 5-10-min delayed T1-weighted spoiled gradient echo images were acquired in all patients. Determination was made of lesion size, number, morphology, and signal intensity of lesions on all sequences. Seven patients had solitary lesions and 8 patients had multiple lesions. Focal lesions of hepatic lymphoma ranged in size from 5 mm to 15 cm. They were well defined masses with mild to moderate low signal intensity relative to liver on T1-weighted images. Lymphoma lesions in 6 patients were moderately high in signal intensity on T2-weighted images compared with liver (Type I lesions), and enhancement of lesions was intense on early post-gadolinium images in 5 of these patients. Lymphoma lesions in 6 patients were mildly hypointense to mildly hyperintense on T2-weighted images compared to liver (Type II lesions), and lesions in 5 of these patients enhanced minimally on the early post-gadolinium spoiled gradient echo images. The remaining 3 patients had received chemotherapy before the magnetic resonance examination, and the imaging findings varied reflecting presumed differences in treatment responses. Transient ill defined perilesional enhancement on immediate post-gadolinium spoiled gradient echo images was observed in 9 patients including patients with either type of lesion. Focal lesions of hepatic lymphoma are usually low in signal intensity on T1-weighted images but have variable signal intensity on T2-weighted images. In general, lesions that are mildly hypointense to minimally hyperintense in signal intensity on T2-weighted images enhance minimally, and lesions moderately high in signal intensity of T2-weighted images enhance intensely. Transient increased perilesional enhancement is common.

Expression of adhesion molecules in primary B-cell gastric lymphoma and lymphoid follicles

To determine whether primary B-cell gastric lymphoma (GL) is one entity, we examined the expression of three adhesion molecules in the microvasculature of lymphomas. Stromal cells, including vascular endothelial cells, within lymphoid follicies of the gastric mucosa were also investigated. Twenty-two surgical specimens of GL were classified into low-grade malignant lymphoma arising from mucosa-associated lymphoid tissue (low-grade lymphoma, n = 9), and high-grade malignant lymphoma with (secondary high-grade lymphoma, n = 6) or without (primary high-grade lymphoma, n = 7) a low-grade component. The proportion of venules positive for ELAM-1 or VCAM-1 was significantly higher (P < 0.001) in primary high-grade lymphoma than in low-grade and secondary high-grade lymphomas. In gastric lymphoid follicles, the stromal cells of the germinal centre (GC) were positive for ICAM-1, ELAM-1, and VCAM-1, but the stromal cells of the marginal zone (MZ) were positive only for ICAM-1. We found two patterns of adhesion molecule expression in gastric lymphoid follicles, the MZ pattern and the GC pattern. Low-grade and secondary high-grade lymphomas, which had the MZ pattern, might be of MZ-cell lineage, but most primary high-grade lymphomas, which had the GC pattern, might be of follicular centre cell lineage.

The nonlymphoid microenvironment of reactive follicles and lymphomas of follicular origin as defined by immunohistology on paraffin-embedded tissues

Twenty-five reactive lymph nodes, 10 palatine tonsils, and 72 B-cell non-Hodgkin's lymphomas (NHLs) of supposed follicular origin were investigated in an immunohistologic study of fixed, paraffin-embedded tissues using a panel of monoclonal antibodies reactive with antigens resistant against fixation and paraffin-embedding techniques together with polyclonal antibodies. The results concerning the microenvironmental organization of reactive lymphoid follicles confirmed that the distribution of CD21+ and CD23+ dendritic reticulum cells, vimentin+ fibroblastic reticulum cells, and CD68+ tingible-body macrophages is heterogeneous with reference to their immunostaining patterns and topographic localization within the germinal center and mantle zone. Moreover, a close microenvironmental similarity between the follicular lymphomas of supposed germinal center or mantle zone origin and their normal counterparts was noted. The study of the microenvironment of the B-zone small lymphocytic lymphoma cases, showing the same distribution patterns for the nonlymphoid cells as seen in mantle zone lymphomas, corroborated the supposed follicular origin of this unusual variant of small lymphocytic lymphoma. In conclusion, this study shows that monoclonal antibodies recognizing CD21, CD23, and CD68 antigens may be valuable additions to vimentin, S-100 protein, laminin, and type IV collagen antibodies for investigating the microenvironmental organization of lymphoid tissues in both normal and neoplastic conditions.

Nasal peripheral T-cell lymphoma: a 20-year review of cases treated in Scotland

The nasal peripheral (post-thymic) T-cell lymphoma is an important cause of the midline granuloma syndrome (MGS), in which ulceration and destruction of the tissues of the nose and paranasal sinuses occurs. We reviewed the histology of 9 cases of the MGS treated with radiotherapy, and, using immunocytochemistry, showed 8 cases to be peripheral T-cell lymphomas (PTCL) and 1 a B-cell lymphoma. All patients received radiotherapy and 2 died shortly after treatment from unrelated causes. Two patients with T-cell lymphoma and the solitary case of B-cell lymphoma achieved long-term disease-free survival. The 4 remaining cases of T-cell lymphoma relapsed locally at a median interval of 3.5 months despite megavoltage irradiation of 45-50 Gy (in 3 cases) and inclusion of uninvolved paranasal sinuses and the nasopharynx in the field (in 2 cases). All patients with local relapse achieved, and remain in, remission after treatment with alkylating agents and prednisolone. The disappointing response of some cases of nasal T-cell lymphoma to radiotherapy has been reported by others, and this may be due partly to the heterogeneity of nasal lymphomas. We are unable to provide clear guidelines for treatment but suggest that a role exists for initial treatment with oral alkylating agents and steroids in newly diagnosed cases.

High endothelial venules in B-cell non-Hodgkin malignant lymphomas

The number of high endothelial venules (HEVs) per unit area was determined in 55 B-cell non-Hodgkin malignant lymphomas (nHMLs) classified according to the Kiel classification. The number of HEVs per unit area was significantly different between low- and high-grade B-cell nHMLs. In the low-grade group, a large number of HEVs with preserved structure were present, whereas in high-grade tumours the HEVs appeared damaged. The present findings support the previous observation attributing prognostic relevance to lymphocyte recirculation in nHMLs.

Tumor-related angiogenesis

In recent years, tumor-related angiogenesis has become an important field of research in oncology. It could be stated that growth of solid tumors is completely dependent on neovascularization to provide the tumor with all required nutrients. Special compounds (tumor angiogenesis factor[s]) are released by tumor cells into the environment to stimulate different types of normal cells to become active for the tumor. In particular, endothelial cells of neighboring capillaries are induced to react. They disintegrate their own basal lamina, detach from their neighbors, enter the extracellular matrix, and migrate toward the tumor mass. Cell divisions occur within such sprouts, thereby increasing the number of migrating endothelial cells. Strands of such cells are formed, and inter- and intracellular lumina develop. Loops of these hollow strands anastomose to form a network of new vessels which become connected with the blood circulation. The tumor mass thus becomes vascularized and can continue to grow. The prevention of neoangiogenesis has an enormous impact on cancer treatment by inhibiting the growth of the tumor. In this review, all important aspects of tumor-related angiogenesis are presented.

Histopathology and immunohistochemistry of peripheral T cell lymphomas: a proposal for their classification

Based on the results of histological and immunohistochemical observations of a large number of peripheral T cell lymphomas from China, England, Germany and Japan, histological and cytological morphology were correlated with immunophenotype, aetiological association with HTLV-1, and clinical behaviour to produce a working classification of the T cell lymphomas. This classification, based mainly on cytological criteria, divides the peripheral T cell lymphomas into tumours of low grade and high grade malignancy. Adult T cell lymphoma/leukaemia (ATLL) is caused by HTLV-1 and belongs chiefly to the high grade category. Some tumours are characterised by an admixture of other cells (epithelioid cells, follicular dendritic cells, etc) and structures (high endothelial venules, follicles), which may indicate the secretion of lymphokines by the tumour cells. Clear cells seem to be specific for T cell lymphomas and may occur in various types of peripheral T cell lymphoma.

S-100 protein, fibronectin, and laminin immunostaining in lymphomas of follicular center cell origin

Forty-nine paraffin-embedded biopsy specimens of involved nodal and extranodal tissue (bone marrow, spleen, and liver) from 13 patients with follicular center cell lymphomas (FCCL) and 14 with small lymphocytic lymphomas (SLL), including 11 cases with chronic lymphocytic leukemia, were tested for S-100 protein immunoreactivity. Analysis for fibronectin and laminin immunoreactivities was limited to the lymph node biopsy specimens. In FCCL, S-100-positive dendritic reticulum cells (DRCs) were found in 23 of the 26 tissue specimens examined, regardless of the involved sites and the growth pattern. Cases with completely or predominantly follicular pattern were usually associated with a spherical meshwork pattern of S-100-positive DRCs; in the FCCL specimens with a diffuse pattern (lymph nodes and bone marrow) as well as in the specimen areas with a minimally follicular tumor pattern, S-100-positive DRCs were consistently fewer in number and composed loosely aggregated nests. No S-100-positive DRCs were found in all the biopsy specimens in SLL. Concerning fibronectin and laminin immunostainings, results showed that no differences were present between areas of follicular and diffuse neoplastic growth and that the neoplastic growth of FCCL maintained for each antiserum the same distribution pattern as that seen in normal follicles. Analysis of the microenvironmental components as revealed with antisera used in the current study--particularly with anti-S-100 protein antiserum--appears to be a useful adjunct for the identification of FCCL in paraffin-embedded biopsy specimens, especially in extranodal sites.

Lectin I of Ulex europaeus as a marker for a subset of histiocytic tumours of the lymph node

We describe four lymph node based tumours in which numerous neoplastic cells and some mitotic figures were characterized by staining affinity for Lectin I of Ulex europaeus (UEA-I). The patients had no vascular or epithelial tumours and presented symptoms suggestive of a systemic lymphoproliferative disease. Histologically, the tumours were composed of large, cohesive, cells which were mainly located in the paracortex. UEA-I reactivity was more evident in the Golgi area and was present in large mononucleated cells often arranged to delimit vascular-like spaces. The neoplastic cells were weakly muramidase-positive in one case, and were ANAE+/AP+ in two other cases. Large dots of UEA-I reactivity were detected in S-100+/muramidase-negative Langerhans-like cells present in one case of Letterer-Siwe disease. UEA-I staining was consistently negative in 20 cases of B cell- or T cell lymphoma and in 9 other cases of histiocytic lymphoma. It is suggested that UEA-I+ tumours of the lymph nodes are part of a distinct subset of histiocytic malignancies whose neoplastic cells present some morphological and phenotypic properties normally associated with endothelial cells.