Biomedical subjects
J Vassallo
Publications and source records attributed to J Vassallo.
Primitive malignant lymphomas of bone. Study of 14 cases.
Between 1953 and 1956, 54 cases of bone tumors initially diagnosed as reticulum cell sarcoma, lymphosarcoma and malignant lymphoma were found in the file of Department of Pathology at A.C. Camargo Hospital. After review of patients' charts, slides and immunohistochemical study only 14 were admitted in the study as primary lymphoma of bone. 11 were of high grade malignancy (8 centroblastic, 1 multilobated cell type, 1 immunoblastic and 1 lymphoblastic) and 3 were of low grade malignancy according to the Kiel classification. No case of true histiocytic sarcoma was found.
Biological characterization of human bone tumors. X. The proliferation behavior of macrophages as compared to fibroblastic cells in malignant fibrous histiocytoma and giant cell tumor of bone.
Seven giant cell tumors of bone and four malignant fibrous histiocytomas were studied immunohistochemically with different monoclonal antibodies to the mononuclear phagocyte system (MPS), to HLA-DR antigens, and to a proliferation-associated nuclear antigen (KI-67), in order to clarify the role of macrophages in these tumors. A part of the mononuclear cells stained positive with antibodies against the MPS. Antibody 25-F-9 against mature tissue macrophages showed the strongest reaction. The osteoclast-like giant cells also stained positive with this antibody. Fibroblast-like stromal cells, however, showed negative reactions to all antibodies against MPS cells. A double-labeling immunohistological technique was used to detect the proliferating cell population in these tumors. The fibroblast-like cells that were negative for MPS markers, were positively labeled with the monoclonal antibody Ki-67 against a proliferation-associated nuclear antigen, whereas a negative reaction to Ki-67 was seen in cells positive with antibodies to the MPS. These results support the concept that macrophages are a reactive population in these tumors, whereas the fibroblast-like mesenchymal cells are the proliferating tumor cells.
Flow cytometric DNA analysis of malignant lymphomas with primary bone manifestation.
Malignant lymphomas with primary skeletal manifestation have received controversial evaluation with regard to histological classification and histogenesis. Recent histological and immunohistological studies on the rare bone lymphomas conducted by our team, have shown that they do not differ from primary nodal lymphomas with regard to the spectrum of histological subtypes. The present flow cytometric DNA analysis of paraffin-embedded material from 17 lymphomas documented in the Bone Tumor Registry of Westfalia yielded the following distribution pattern of DNA ploidy: among 12 non-Hodgkin's lymphomas (NHL) (according to the Kiel classification) there was only 1 case of low grade malignancy; this centroblastic-centrocytic lymphoma showed a unimodal diploid DNA histogram. Of 11 highly malignant NHL, 6 were DNA hyperdiploid. Among the 5 cases of Hodgkin's lymphoma, 4 were DNA diploid, (1 nodular sclerosing, 3 mixed types) and one DNA tetraploid (lymphocytic depletion type). Comparison with data from the literature reveals that even with regard to DNA ploidy, malignant lymphomas primarily manifesting in bone do not differ from those of exclusively nodal manifestation.
Malignant lymphomas with primary bone manifestation.
18 malignant lymphomas with initial manifestation in bone were selected from the Bone Tumor Registry of Westfalia at the Münster Institute of Pathology where they had been documented between 1975 and 1985, and evaluated under clinical, radiological and histological aspects. Non-Hodgkin lymphomas were reclassified according to the Kiel nomenclature. Paraffin-embedded material was subjected to immunohistochemical analysis in order to assess the features that could add to the correct characterization of these lymphomas, and to their differentiation from other round cell tumors of bone. Non-Hodgkin lymphomas (NHL) were more common in the collective than Hodgkin's lymphomas (HL). Of 13 NHL, 2 were of low, 11 of high-grade malignancy. The former comprised one centrocytic and one centroblastic/centrocytic, the latter 7 centroblastic, 2 immunoblastic, and 2 lymphoblastic lymphomas. Seven NHL patients with localized tumors survived up to 11 years (mean survival span: 6 yrs) after local therapy (radiation and/or resection). Another NHL patient, however, had multiple bone lesions, and died within a year. Analysis for leukocyte common antigen was positive in 9/12 NHL cases, reaction with Ki-B-3, a marker of B-lymphocytes, was positive in 7/12 cases. No lymphoma cells were found to react positively with lysozyme, alpha 1-antitrypsin, or alpha 1-antichymotrypsin. It is concluded that localized lymphomas of bone respond well to appropriate local therapy; immunohistochemical investigation may be useful to characterize the true cellular origin of these tumors, and may help to differentiate them from other round cell tumors of bone.
Histological and cytological heterogeneity of bone marrow in Philadelphia-positive chronic myelogenous leukaemia at diagnosis.
Cytological and histological features of the bone marrow in Philadelphia-positive chronic myelogenous leukaemia (CML) at diagnosis were analysed in a prospective study. Formerly described (Frisch et al, 1984) subtypes GRAN and GRAN/MEG were found, and myelofibrosis and incipient blast crisis could also be detected. A more or less continuous spectrum of number and degree of atypias in megakaryocytes was found. Biopsy and imprint were complementary in making differential diagnosis of both subtypes. Cytologically, type GRAN/MEG was characterized by a mixed proliferation of neutrophil, eosinophil and basophil series, besides proliferation of megakaryocytes. Type GRAN showed a predominantly neutrophilic proliferation. The importance of performing bone marrow analysis in evaluation of CML patients is discussed.
Biological characterization of human bone tumors. VIII. Expression of HLA-DR antigens in bone tumors and tumor-like lesions.
A total of 45 cases of bone tumors and tumor-like lesions were studied in order to determine the expression of an HLA-DR antigen by the monoclonal antibody 910-D-7, and its possible correlation with histology, using the indirect immunoperoxidase method on frozen sections. The pattern of antigen expression was nearly constant for the individual cell types, though varying in intensity, and did not depend on the biological behavior of the respective lesions. No clear correlation could be established between antigen expression and cell maturation. Although the biological significance of antigen expression in these tumors is not yet understood, it is clear that here, too, the mere presence of an HLA-DR antigen cannot be interpreted as a sign of malignant transformation.
Canine lymphomas: a morphological and immunohistochemical study of 55 cases, with observations on p53 immunoexpression.
The purpose was to determine the immunophenotype of canine lymphomas (CLs) classified according to the WHO nomenclature for domestic animals, and to relate these findings to the immunoexpression of p53 protein. Lymphomas were immunophenotyped with antibodies to CD79a, CD3, and p53 protein, suitable for paraffin wax-embedded tissue sections. Of 55 cases, 40 (72.7%) were of the B-cell phenotype, 12 (21.8%) of the T-cell phenotype, and three (5.4%) were non-B-non-T lymphomas. Of the 40 B-cell lymphomas, 31 were of the large B-cell type, six were lymphoplasmacytic, one lymphocytic, one follicular (grade II) and one unclassified low-grade. One of the peripheral T-cell lymphomas was morphologically consistent with anaplastic large cell lymphoma. Immunolabelling for p53 occurred in 24 B-cell and seven T-cell lymphomas. Lymphomas with high grade histology showed a significantly increased frequency of p53 positivity (P = 0.01). Positivity for p53 (more than 10% positive cells) tended to be associated with the T-cell phenotype (P = 0.06). Mean patient age was significantly higher in p53-positive cases (P = 0.02). These data are comparable with findings in human lymphomas.
Diagnosis of hepatitis C virus in Brazilian blood donors using a reverse transcriptase nested polymerase chain reaction: comparison with enzyme immunoassay and recombinant protein immunoblot assay.
Screening blood donations for anti-HCV antibodies and alanine aminotransferase (ALT) serum levels generally prevents the transmission of hepatitis C virus (HCV) by transfusion. The aim of the present study was to evaluate the efficiency of the enzyme immunoassay (EIA) screening policy in identifying potentially infectious blood donors capable to transmit hepatitis C through blood transfusion. We have used a reverse transcriptase (RT)-nested polymerase chain reaction (PCR) to investigate the presence of HCV-RNA in blood donors. The prevalence of HCV-RNA positive individuals was compared with the recombinant immunoblot assay (RIBA-2) results in order to assess the usefulness of both tests as confirmatory assays. Both tests results were also compared with the EIA-2 OD/C ratio (optical densities of the samples divided by the cut off value). ALT results were expressed as the ALT quotient (qALT), calculated dividing the ALT value of the samples by the maximum normal value (53UI/l) for the method. Donors (n=178) were divided into five groups according to their EIA anti-HCV status and qALT: group A (EIA> or = 3, ALT<1), group B (EIA> or = 3, ALT>1), grou (1< or = EIA< 3, ALT<1), group D (1< or = EIA<3, ALT>1) and group E (EIA< or = 0.7). HCV sequences were detected by RT-nested PCR, using primers for the most conserved region of viral genome. RIBA-2 was applied to the same samples. In group A (n=6), all samples were positive by RT-nested PCR and RIBA-2. Among 124 samples in group B, 120 (96.8%) were RIBA-2 positive and 4 (3.2%) were RIBA-2 indeterminate but were seropositive for antigen c22.3. In group B, 109 (87.9%) of the RIBA-2 positive samples were also RT-nested PCR positive, as well as were all RIBA-2 indeterminate samples. In group C, all samples (n=9) were RT-nested PCR negative: 4 (44.4%) were also RIBA-2 negative, 4 (44.4%) were RIBA-2 positive and 1 (11.1%) was RIBA-2 indeterminate. HCV-RNA was detected by RT-nested PCR in 3 (37.5%) out of 8 samples in group D. Only one of them was also RIBA-2 positive, all the others were RIBA-2 indeterminate. All of the group E samples (controls) were RT- nested PCR and RIBA-2 negative. Our study suggests a strong relation between anti-HCV EIA-2 ratio > or = 3 and detectable HCV-RNA by RT-nested PCR. We have also noted that blood donors with RIBA-2 indeterminate presented a high degree of detectable HCV-RNA using RT-nested PCR (75%), especially when the c22.3 band was detected.
Multiple lymphoid nodules in bone marrow biopsy in immunocompetent patient with cytomegalovirus infection: an immunohistochemical analysis.
In Brazil, a high prevalence of cytomegalovirus (CMV) infection has been documented. In immunocompetent adults CMV infection is usually asymptomatic and therefore morphologic and immunophenotypic bone marrow changes have rarely been described. The authors report the case of a previously healthy patient who developed fever of undetermined origin. The diagnosis of acute CMV infection was based on serological testing. A computed tomographic scan showed mediastinal lymphadenopathy. A bone marrow biopsy revealed a hypercellular haematopoiesis with eosinophilia and large mixed T- and B-cell lymphoid aggregates. In spite of bcl-2 positivity, their reactive nature was demonstrated. Polymerase chain reaction (PCR) and immunohistochemistry were unable to detect CMV-DNA in paraffin-embedded bone marrow sections. Much like in other systemic disorders, the lymphoid nodules in this case seemed to be caused by immunological mechanisms, possibly due to cytokines released in response to the systemic infectious process.
Hemophagocytic syndrome: pitfalls in its diagnosis.
The hemophagocytic syndrome (HS) is characterized by a clinical picture of fever, hepatosplenomegaly, lymphadenopathy and peripheral pancytopenia. The morphologic hallmark of this syndrome is the phagocytosis of hematopoietic elements by morphologically normal macrophages. HS is considered rare and may be a primary disease or associated to viral, infection, neoplasias or autoimmune diseases. Treatment is controversial and its evolution is often fatal. Anatomo-pathological evaluation shows the phenomenon of hemophagocytosis in several organs, especially the hematopoietic tissues. We describe a case of HS, discuss its possible causes, its clinical and pathologic features, its pathophysiology and therapeutic possibilities.
Immunohistochemical study of basement membrane collagen IV in uterine cervix carcinoma.
CONTEXT: The integrity of basement membrane (BM) is damaged during the evolution of a benign or potentially malignant lesion into a malignant one, in which it may undergo several degrees of discontinuity as a necessary condition for the invasive process. Immunostaining for collagen IV, which is exclusively found in BM, has been used to evaluate its formation in neoplastic and benign lesions of several organs. OBJECTIVE: To investigate BM continuity pattern in squamous carcinoma "in situ" (CIS), microinvasive (MIC) and invasive (IC) squamous cell carcinoma of the uterine cervix, and to find out if BM expression could be useful in the diagnosis of early stromal invasion (MIC). DESIGN: Archival material between 1988 and 1993 was studied at the Pathological Anatomy Department-Unicamp. PROCEDURES: The selected cases, previously formalin fixed and paraffin embedded, were reviewed retrospectively by submitting them to immunohistochemical study via the avidin-biotin-peroxidase method using a monoclonal antibody anticollagen IV. RESULTS: In all, 17 cases of CIS, 16 of MIC and 21 of IC were evaluated. All IC cases showed evident BM discontinuity, either focal or diffuse. In the CIS group, a continuous BM pattern was predominant, being focally disrupted in only 2/17 cases (11.8%). The MIC group showed an intermediate pattern, but with a clear tendency to BM discontinuity in 10/16 cases (62.5%). Inflammatory infiltrate, a variable also studied, cannot be considered responsible for BM discontinuity, since there was no statistical correlation between them. CONCLUSION: We conclude that immunostaining for collagen IV may contribute to the diagnosis of stromal invasion by BM discontinuity.
Borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis in deer ticks, Delaware.
During the 1998 hunting season in Delaware, 1,480 ticks were collected from 252 white- tailed deer; 98% were Ixodes scapularis, a significant increase from the 85% reported in 1988. Ticks were tested for Borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis. Infection rates remained stable in New Castle and Kent counties, but increased from <1% to 8% in sussex county.
Immunohistochemical demonstration of papillomavirus infection in condylomatous and preneoplastic lesions of the lower female genital tract.
An immunoperoxidase study of 250 cases of condyloma of the female genital tract showed HPV expression in 45% of the cases. The flat form was the most frequent (191/250 cases). Condylomatous lesions were associated with dysplasia, in situ or micro-invasive carcinoma in 43% of the cases. The results support the role of the HPV as a possible carcinogenic agent in the female genital tract.
Peripheral T-cell lymphoma in HIV-positive patients.
Two cases of peripheral T-cell lymphomas in HIV-positive patients are reported: one case of T-pleomorphic small cell non-Hodgkin lymphoma in a 27 year-old bisexual male, and one case of a T-pleomorphic medium and large cell non-Hodgkin lymphoma in a 27 year-old female, whose husband was drug addicted. Both cases were studied on a morphological and immunohistological basis.
Hodgkin's disease in Brazil: a clinicopathologic study.
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