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During early stages of lymphocyte development, genes for antigen receptors (immunoglobulin and T-cell receptor proteins) undergo rearrangements of their DNA sequences. The resulting configurations of rearranged DNA are highly variable from cell to cell and serve as genetic markers for individual lymphocytes. These markers can be utilized to detect clonal lymphocytic proliferations, as seen in lymphoid malignancies, and to identify the lineage of lymphoid neoplasms. Chromosomal rearrangements involving recombination between the DNA of antigen receptor genes and other sites in the genome also occur in lymphoid neoplasms, and molecular analysis of such rearrangements is potentially useful in the diagnosis of lymphomas and leukemias.

The clinical, morphological and immunological findings in nine cases of relapsing lymphocyte predominance Hodgkin's disease (LPHD) are examined. Six patients had initial biopsies demonstrating nodular lymphocytic and/or histiocytic (L&H) LPHD; Leu-M1 was not expressed by any of the atypical cells in these cases. All six demonstrated one or more recurrences of nodular L & H LPHD; four are currently free of disease, one died of non-Hodgkin's lymphoma and another died of leukaemia. Two patients had initial biopsies demonstrating diffuse LPHD, with only rare multilobated atypical cells (L & H variants). Both patients had recurrences interpreted as mixed cellularity Hodgkin's disease, 10 and 15 years after initial therapy and both died with lymphocyte depleted Hodgkin's disease. The atypical cells in the initial biopsies and in subsequent recurrences failed to express Leu-M1, but did express leukocyte common antigen. The initial biopsy from the final patient was histologically interpreted as focal involvement by LPHD, but interfollicular Hodgkin's disease was considered after the Leu-M1 stain revealed additional atypical cells. The disease relapsed and the patient died with typical nodular sclerosing Hodgkin's disease. The pattern of the relapses supports the concept that the histological entity of LPHD may include several distinct clinicopathological subgroups.

We applied a panel of antibodies to formalin-fixed, paraffin-embedded sections of 55 renal cell carcinomas using a three-stage immunoperoxidase technique. The antibody panel included two anti-keratins, AE1 and CAM5.2, anti-epithelial membrane antigen (EMA), anti-vimentin, anti-S100 protein, and the anti-leukocyte marker PD7/26. Forty-eight of 55 renal cell carcinomas expressed keratins. CAM5.2 stained 46 tumors (84%) and AE1 stained 37 neoplasms (67%). AE1 reacted with two CAM5.2-negative tumors. EMA was expressed by 35 carcinomas (64%), including three of the CAM5.2-negative neoplasms. Therefore, using all three antibodies, 50 neoplasms (91%) expressed antigens of epithelial differentiation. Anti-EMA and AE1 were complementary to each other; the combination stained 46 of the carcinomas, comparable with CAM5.2 alone. Vimentin was expressed by 26 tumors (47%), and S100 was expressed by one. PD7/26 did not stain any of the cases. Vimentin expression correlated with nuclear grade; low nuclear grade neoplasms infrequently expressed vimentin, while the converse was true for high nuclear grade tumors. Keratin expression was related to tumor cell type and histologic pattern, as fewer neoplasms of clear cell type and with a solid pattern expressed keratins. In contrast, all papillary and eight of nine (89%) spindled carcinomas expressed keratins.

One of the most common karyotypic abnormalities is the t(14;18) translocation, which is found in many lymphomas that have a characteristic follicular morphology. Recent molecular studies have shown that this chromosomal translocation results in the juxtaposition of the candidate proto-oncogene bcl-2 (B-cell leukemia-lymphoma) on chromosome 18 with the immunoglobulin heavy-chain locus on chromosome 14. However, because performing accurate cytogenetic studies in solid hematolymphoid neoplasms is difficult, knowledge of the prevalence of the t(14;18) translocation and, by association, the extent of bcl-2 involvement in human lymphomas is limited. We used a number of chromosome-18 DNA probes to analyze various subtypes of Hodgkin's and non-Hodgkin's lymphomas and test for structural abnormalities near or within the bcl-2 gene. Molecular features of the t(14;18) translocation were found in virtually all follicular neoplasms and about 28 percent of diffuse large-cell lymphomas. No changes in bcl-2 were found in several other subtypes of Hodgkin's and non-Hodgkin's lymphomas, including those previously suggested to originate from follicular-center cells and those about which cytogenetic data have been difficult to obtain. Our findings suggest a close pathogenetic relation between bcl-2 and a large group of non-Hodgkin's lymphomas, both with and without a follicular morphology. The methods employed in this study may be useful in improving the accuracy of diagnosis and subclassification of malignant lymphomas.

In man, lymphocyte binding to high endothelial venules (HEVs) involves specific 85-95 kd cell surface glycoprotein(s) recognized by the monoclonal antibodies Hermes-1 and Hermes-3. These putative "homing receptor" molecule(s) are believed to play an important role in the normal regulation of lymphocyte circulation. To investigate the possibility that homing receptors also play a role in the biology of lymphoid malignancies, the authors studied over 300 cases of non-Hodgkin's lymphoma by immunohistologic staining with Hermes-1 and -3, antibodies that define two distinct epitopes on the gp 85-95 putative homing receptor molecules. Furthermore, they directly compared expression of the Hermes-3 antigen with clinical extent of disease in 57 patients with diffuse large cell lymphoma. They found that staining of the various subtypes of lymphoma was heterogeneous, and in general correlated with patterns of expression seen in benign lymphoid populations. Essentially all normal lymphoid populations examined, except germinal center B cells and most cortical thymocytes, bear a high level of homing receptor antigen. Similarly, nearly all peripheral T-cell lymphomas, diffuse small cell lymphomas of B lineage, and plasma cell tumors were positive for homing receptor antigen (95%, 97%, and 100%, respectively). Small noncleaved cell, follicular, and diffuse large cell lymphomas of B lineage, tumors having morphologic or immunologic features resembling germinal center cells, frequently failed to express Hermes-defined epitopes (81%, 41%, 25% Hermes-3-, respectively). Antigen expression in T-lymphoblastic lymphomas strongly correlated with immunophenotypic subtypes: only 8% of CD4+/CD8+ were Hermes-1+ versus 86% of CD4-/CD8- and 43% of CD4+/CD8-. Hermes-3 expression by cases of diffuse, large cell lymphoma which showed generalized lymph node involvement (a pattern strongly suggestive of HEV-mediated spread; 100% Hermes-3+, mean intensity 3.4) was higher than that of cases with localized or multifocal, contiguous involvement (consistent with lymphatic spread; 69% Hermes-3+, mean intensity 2.2), but these differences did not achieve statistical significance. The results indicate that homing receptor antigen expression, although perhaps necessary for wide-spread blood-borne lymphoma dissemination to lymphoid sites, is not in and of itself sufficient to predict such behavior in this subtype of lymphoid malignancy.

Leu-6 is an antigen expressed by immature T cells, Langerhans cells, and indeterminate cells, the latter two of which are dendritic cells found predominantly within the skin. In dermatopathic lymphadenopathy, the paracortex is expanded by T cells and dendritic cells, including Langerhans cells. While the paracortex also contains Leu-6+ cells, the nature of such cells in lymph nodes has been controversial. To determine the characteristics of Leu-6+ paracortical cells, their morphologic, antigenic, and enzymatic features were studied in lymph nodes showing dermatopathic lymphadenopathy or reactive follicular hyperplasia. Immunologic studies with plastic, frozen, and paraffin sections demonstrated a dendritic cell morphology, a dendritic cell lineage phenotype (L3B12+, HLA-A,B,C+, HLA-DR+, S-100+), and the absence of T-cell lineage phenotype. These findings were corroborated by the enzymatic phenotype of these cells observed in plastic sections (membrane ATPase+, weak paranuclear acid phosphatase+, weak paranuclear alpha-napthylacetate esterase+). Although all paracortical dendritic cells were otherwise identical, only a subset of these cells were Leu-6+. The close phenotypic similarity between these Leu-6+ and Leu-6- paracortical dendritic cell subsets suggests a close ontogenetic relation. Furthermore, the greater abundance of the Leu-6+ subset in dermatopathic lymph nodes than in nodes exhibiting only reactive follicular hyperplasia, in conjunction with the presence of Leu-6+ dendritic cells within the sinuses of dermatopathic lymph nodes, suggests that at least some of the paracortical Leu-6+ cells are Leu-6+ Langerhans cells or indeterminate cells derived from the skin via the afferent lymphatics.

The histologic, ultrastructural, and immunologic characteristics of two signet-ring cell lymphomas of T-cell derivation are presented. Histologically, both lymphomas were diffuse large cell lymphomas with many neoplastic cells containing cytoplasmic vacuoles imparting a signet-ring configuration. Ultrastructural examination revealed the vacuoles to consist of electron-lucent spaces containing variable numbers of microspherules. Immunohistochemical studies showed that both lymphomas expressed T-cell phenotypes with no reactivity with antibodies to B-cell antigens. In contrast to previous reports which have shown signet-ring cell lymphomas to be invariably B-cell in derivation and usually follicular center cell type, this study demonstrates that these lymphomas may also be of T-cell origin.

The authors applied a battery of monoclonal antibodies to T cells and other hematolymphoid cells on frozen tissue sections of lymph nodes with involvement by MF and DL, both with and without a history of MF. All 13 lymph nodes showing histologic involvement with MF showed immunophenotypic abnormalities. All of these cases showed significant loss of Leu-9 expression, and 10 cases showed significant loss of Leu-8 expression. In addition, occasional cases showed loss of the pan-T-cell markers Leu-1, 4, and 5. All cases of DL of histologic grade LN-0 or 1, with or without a history of MF, showed a predominance of T helper cells in paracortical regions without evidence of immunophenotypic abnormalities. Three of the 4 cases of DL of histologic grade LN-2 or 3 showed significant loss of Leu-8 and/or Leu-9 expression identified by a decrease in the ratio of paracortical Leu-8/Leu-4 or Leu-9/Leu-4-expressing cells, all cases with a history of possible or definite MF. These results raise the possibility that the immunologic methods employed may be able to identify cases of DL with early involvement by MF.

The clinical records and initial biopsy materials from 76 patients with mixed small-cleaved and large-cell lymphoma containing both a follicular and diffuse architectural pattern were reviewed. The characteristics of this group, treated at Stanford University Medical Center (SUMC) between 1963 and 1983, are described. The 5-year actuarial survival and freedom from progression are 70% and 27.5%, respectively. Classification according to the degree of follicularity indicated that patients with focally follicular areas (ie, less than 25% of the histologic section) have a significantly worse freedom from progression and overall survival at 5 years compared with those patients with a predominantly follicular architecture (ie, greater than 50% follicular areas). Based on our analysis, we feel that the degree of follicularity is an important prognostic factor and that mixed lymphoma patients with only focally follicular areas behave more like an intermediate-grade lymphoma and should be treated aggressively.

Using an immunoperoxidase technique that identifies both surface and cytoplasmic antigen expression, the authors examined 28 benign reactive lymphorproliferative lesions and 55 T-lineage lymphomas for reactivity with CD3 (Leu-4; T-cell receptor-associated antigen) and beta F1 antibodies, the latter recognizing nonpolymorphic determinants on T-cell receptor beta chains. Consistent with previous observations that these two antigens are co-expressed on the vast majority of thymocytes, peripheral blood T cells and tonsillar T cells, all 28 reactive lymphoproliferations showed essentially identical patterns of CD3 and beta F1 expression. In contrast, only 29 of 55 T-lineage lymphomas displayed coexpression of these antigens. Among 33 peripheral T-cell lymphomas, 11 cases showed CD3/beta F1 discordance (7 CD3+/beta F1-; 4 CD3-/beta F1+), and 5 showed absence of both these antigens. Nine of 22 T-lymphoblastic lymphomas showed CD3/beta F1 discordance (all CD3+/beta F1-), and 1 case was CD3-/beta F1-. These patterns of CD3/beta F1 expression, along with the patterns of CD2, CD4, CD5, CD7, and CD8 antigen expression in these neoplasms, indicate that T-cell lymphomas can manifest phenotypes not apparently reflective of normal T populations and suggest the presence of abnormal gene expression in these malignancies. The existence of aberrant phenotypes in T-cell neoplasia suggests caution in interpretation of investigations using T-lineage malignancies as models of normal T-cell biology. Finally, the identification of phenotypic abnormalities in T-lineage populations can be of great diagnostic usefulness in the delineation of benign versus malignant T-cell proliferations.

This study compared repair of myocardial wounds covered with autologous pericardium to healing of wounds covered with glutaraldehyde-preserved bovine pericardium in an experimental canine model. Right (RV) and left (LV) full thickness ventriculotomies were made and closed. In the control group (n = 12), the pericardium was closed over the wound; in the experimental group (n = 12), wounds were covered with bovine pericardium. Animals were sacrificed at 14, 21, 28, and 42 days. After excising the pericardium, 6 mm punch biopsies of normal RV, RV wound, normal LV, and LV wound were assayed for hydroxyproline (HPro). Both autologous and bovine pericardium became densely adherent to the wounds. Bovine pericardium was mildly adherent over unwounded areas, while autologous pericardium was usually free. Normal RV contained more than twice as much HPro as normal LV (5.4 +/- 0.57 micrograms/mg vs 1.7 +/- 0.35 micrograms/mg, P less than 0.0002). A gradual rise in HPro over time was seen in both groups, but this increase was statistically significant only at 42 days (P less than 0.05). There was no significant difference in HPro between wounds covered with autologous pericardium and those covered with bovine grafts (P = 0.13) at any of the sample times in this study. In this experimental canine model, the pericardium does not appear to play a prominent role in myocardial wound healing by contributing collagen-producing fibroblasts. Furthermore, the bovine pericardial xenograft becomes densely adherent to LV and RV incisions. In the clinical setting, such may make reoperation more hazardous when the heart has been previously incised or coronary bypass grafts have been constructed.

The influence of long-term verapamil administration on the consequences of Trypanosoma cruzi infection in mice was studied with regard to animal mortality, morbidity, myocardial pathologic features and myocardial beta-adrenergic adenylate cyclase activity. Verapamil administration dramatically decreased the mortality rate from 60% to 6% during the 70 day period of infection. Three clinical stages of infection were evident. In the acute stage (17 days after infection with maximal parasitemia), verapamil treatment not only decreased the incidence of myocardial disease (fibrosis and inflammation), but also protected myocardial beta-adrenergic adenylate cyclase activity. In addition, there was no increase in total body weight, which was regarded as an index of right-sided heart failure. In the subacute stage (30 to 60 days after infection), administration of verapamil continued to decrease myocardial disease and preserve beta-adrenergic adenylate cyclase activity. In addition, verapamil ameliorated the morbidity and mortality associated with this stage of infection. The chronic stage of infection was characterized by a decrease in myocardial disease and in beta-adrenergic adenylate cyclase activity. Thus, independent of the state of infection, long-term verapamil treatment enhanced beta-adrenergic adenylate cyclase activity. In addition, verapamil ameliorated the morbidity associated with infection. Although the relation among these various effects of verapamil in the setting of T. cruzi infection remains to be determined, collectively the results suggested that verapamil administration attenuated the consequences of T. cruzi infection.

The authors report two patients with cutaneous and submucosal non-Hodgkin's lymphoma of probable T-cell phenotype that presented as florid pseudoepitheliomatous hyperplasia. The first patient presented with lesions of the nasopharynx and nose that were originally misdiagnosed as invasive squamous cell carcinoma, causing a delay in appropriate treatment. In the second patient, skin lesions of the thigh and arm closely mimicked squamous cell carcinoma. To prevent misdiagnosis of these lesions, pathologists should adhere to strict morphologic criteria for the diagnosis of squamous cell carcinoma and be aware that malignant lymphoma may be associated with overlying pseudoepitheliomatous hyperplasia. The pathogenesis of pseudoepitheliomatous hyperplasia arising in association with neoplasms is still not clear, but it may be related to the production of cellular growth factors by the inciting tumor.

Nineteen cases of possible non-Hodgkin's lymphoma of the lung were studied by conventional morphologic methods and by immunohistochemical methods employing monoclonal antibodies applied to frozen tissue sections. In five of the 19 cases, the original histologic diagnoses were revised after review of the immunologic findings. Problem areas clarified by immunodiagnosis included the differential diagnoses of pseudolymphoma versus small lymphocytic lymphoma (two cases), Hodgkin's disease versus non-Hodgkin's lymphoma (two cases) and non-Hodgkin's lymphoma versus lymphomatoid granulomatosis (one case). Of the seven lymphomas presenting exclusively in the lung without a prior history of lymphoma, three were small lymphocytic, one was diffuse mixed small cleaved and large cell, and three were diffuse large-cell lymphomas. Four of these lymphomas typed as B-cell, two typed as T-cell, and one was of undefined phenotype.

The physiological effects of high serum levels of ovine GH (oGH) were studied in three generations of transgenic mice carrying a metallothionein 1-(MT)oGH fusion gene. Livers of mice expressing oGH were enlarged, irrespective of the level of serum oGH detected. In mice expressing high levels of oGH, direct measurements of hepatocytes in liver sections revealed that cell and nuclear size were abnormally large. Hepatocytes of different transgenic mice varied from 1.4-2.2 times normal size and hepatocyte nuclei varied from 1.7-2.4 times normal size. In addition, intranuclear inclusions were observed in hepatocytes of transgenic mice and their presence was always associated with high serum levels of oGH. In contrast to female transgenic mice containing mouse MT-human, rat, or bovine GH fusion genes female mice containing the MT oGH fusion gene were fertile and their pituitary glands showed synthesis of GH.

Nineteen, primary, non-lymphoblastic, non-Hodgkin's lymphomas were investigated by conventional morphologic studies as well as immunologic studies using the application of a battery of monoclonal antibodies to frozen tissue sections. Seventeen of the lymphomas were diffuse large cell; one was large cell immunoblastic and one was a follicular and diffuse lymphoma of intermediate differentiation. Thirty-seven percent of the lymphomas showed prominent sclerosis, sometimes associated with the superior vena cava syndrome. Six of the cases showed evidence of immunoglobulin production with light chain restriction. Twelve additional cases were shown to be of B-cell lineage by B1/T015 expression but did not show evidence of immunoglobulin production. One case was a T-cell lymphoma of helper phenotype. Ia expression was found in 14 of 18 cases studied.