Incident cases of primary liver cancer (PLC): proposal for the use of a standardised method in case-definition.

We defined some standardised criteria for classifying incident cases of liver cancer into either Primary Liver Cancer (PLC) or Unspecified Liver Cancer (ULC), on the basis of the diagnostic procedures performed. A pilot hospital-based study (98 cases) was carried out in Verona, northern Italy, in order to assess the feasibility of the method. The same protocol was subsequently applied in a population-based study (349 cases) in Bresica, northern Italy. The percentage of cases with histological verification was 38.7 and 41.8%, respectively, with a wide variation among different hospitals. The percentage of cases we attributed to the PLC category was 78.6% in the hospital-based study and 78.8% in the population-based study. No differences in the proportion of cases attributed to PLC were found according to patients' age, sex or hospital of admission. Repeatability of the method was assessed through a cross-panel review of 198 cases, with a 91.9% interobserver agreement. Implications of this method are discussed and some suggestions for cancer registration and future research are proposed.

Evidence of c-myc gene abnormalities in mediastinal large B-cell lymphoma of young adult age.

Six cases of mediastinal large B-cell lymphoma (MLCL) with sclerosis were analyzed for the presence and patterns of c-myc and bcl-2 loci rearrangements, and for the presence of Epstein-Barr virus DNA sequences by Southern blot hybridization, c-myc gene alterations were found in three of six cases. Two cases showed the presence of mutations or small rearrangements at the 3' end of the first exon. The c-myc gene abnormalities found in these two cases are similar to those observed in the translocation 8;14 of the endemic Burkitt's lymphomas or in its variants t(2;8) and t(8;22). A third case showed a major rearrangement of c-myc gene, with truncation within its first intron, similar to those observed in sporadic Burkitt's and in acquired immunodeficiency-associated lymphomas. None of the cases displayed bcl-2 gene rearrangements or contained viral sequences. Our data suggest a possible role for a translocation-mediated c-myc activation in the pathogenesis of MLCL. Conversely, bcl-2 gene and Epstein-Barr virus do not appear to be involved in the pathogenesis of these peculiar lymphomas. The association between c-myc structural modifications and MLCL also seems to be of relevance in light of the peculiar tendency of this tumor to involve unusual extranodal site (eg, kidney), reminiscent of the spreading attitude of Burkitt's limphomas.

Chemotherapy for invasive thymoma. A 13-year experience.

From 1977 to 1990, 37 patients with Stage III or IV invasive thymoma (20 men and 17 women; median age, 40 years of age) were referred for chemotherapy to the Padova Medical Oncology Department. All patients initially received the same regimen (50 mg/m2 of cisplatin and 40 mg/m2 of doxorubicin intravenously (IV) on day 1, 0.6 mg/m2 of vincristine IV on day 3, and 700 mg/m2 of cyclophosphamide IV on day 4 [ADOC]), recycling at monthly intervals. No life-threatening side effects were noted. The overall clinical response rate (complete response plus partial response) was 91.8%, with 43% complete remissions. Median duration of response and survival were 12 months (range, 2 to 96+ months) and 15 months (range, 5 to 96+ months), respectively. Seven of the 16 complete remissions were pathologically confirmed at subsequent thoracotomy. Other chemotherapy combinations and radiation therapy have been applied as second-line treatment, achieving only minimal responses. In the opinion of the authors, such chemotherapy deserves evaluation for adjuvant and neo-adjuvant treatment of invasive (and/or inoperable) thymoma due to the high complete response rate and overall response rate.

A method for detection of human papillomavirus DNA in stored slides of stained cervical smears.

A simple method was developed for extraction of DNA from stored slides of Papanicolaou stained cervical smears. HPV type 16 DNA was detected by DNA hybridization in 7/10 samples from known HPV-16 positive patients, whereas the 10 samples from negative patients were also negative with our assay. Using our method for obtaining data from stained cervical smears, it will be possible to design and perform historical cohort studies on stored material.

Chemotherapy of invasive thymoma.

Thirty-two patients with stage III or IV invasive thymoma (14 women and 18 men; median age, 40 years) were treated at the Padua Medical Oncology Department from 1977 to 1988. All patients received the following chemotherapy in 4-day courses: 50 mg/m2 of cisplatin intravenously (IV) and 40 mg/m2 of doxorubicin IV on day 1; 0.6 mg/m2 of vincristine IV on day 3; and 700 mg/m2 of cyclophosphamide IV on day 4 (ADOC). The courses were repeated every 3 weeks, and toxic effects were tolerable. The radiologically defined overall clinical response rate (complete plus partial response) was 91% with 47% clinical complete remissions; median time to progression was 11 months (range, 0 to 96) and the median estimated (Kaplan-Meier) progression-free interval was 22 months. Five of the 15 clinical complete remissions were pathologically confirmed at thoracotomy. We believe the ADOC regimen qualifies for adjuvant and preoperative treatment of invasive thymoma due to the high complete response and overall response rates.

Immunohistochemical differentiation of follicular lymphoma from florid reactive follicular hyperplasia with monoclonal antibodies reactive on paraffin sections.

In this study monoclonal antibodies which recognize lymphoid-associated antigens on paraffin sections (LN1, MB2, L26, MT2, UCHL1) have been evaluated to assess their usefulness in the distinction between reactive and neoplastic lesions of lymphoid follicles. Thirty-three follicular lymphoma samples and 36 reactive samples (lymph nodes and tonsils) were analyzed. MT2 appeared as the most valuable immunophenotypic marker as emerged from a comprehensive quantitative evaluation of 2329 reactive follicles and 2288 neoplastic follicles performed on MT2 immunostained sections. MT2-positive follicles were found in all lymphoma samples but one. Overall 1908 of 2288 neoplastic follicles were judged as positive whereas no follicles with comparable strong MT2 immunoreactivity could be found in non neoplastic samples. These latter showed weak MT2 positivity only in about 10% (224/2329) of reactive follicles. This study confirms that MT2 follicular positivity can be considered a reliable marker of follicular neoplasia, although negative results ought to be considered with caution. The detection of centrofollicular cells outside the germinal centers, which is considered a reliable criterion of follicular neoplasia, was highly improved by LN1 immunostaining. On the other hand pan-B antibodies such as L26 and MB2 were less informative because of the large number of B-lymphocytes observed in interfollicular areas of nonneoplastic samples.

Expression and gene rearrangement of the T-cell receptor in human thymomas.

Human thymomas are epithelial neoplasms frequently associated with an exuberant lymphoid component. This mixture of epithelial cells and lymphocytes closely mimicks the organization of normal thymic cortex. However, it is not known whether thymocytes in thymoma express the T-cell receptor (TCR) for the antigen. We have analyzed the molecular configuration of TCR genes and their phenotypic expression in eight thymomas. In all we detected polyclonal rearrangements of TCR genes and cytoplasmic expression of TCR molecules in most thymocytes, thus indicating that rearranged TCR genes in thymomas are functioning genes. In addition, these findings suggest that the epithelial component of thymomas, even if neoplastic, is still capable of directing thymocyte differentiation.

Isolation of multicellular complexes of follicular dendritic cells and lymphocytes: immunophenotypical characterization, electron microscopy and culture studies.

The morphological and phenotypical features of multicellular complexes formed by follicular dendritic cells and lymphocytes (FDC-LC) isolated from human hyperplastic tonsils and adenoids are described. FDC-LC obtained with this procedure were morphologically and immuno-phenotypically heterogeneous. In one type of FDC-LC, probably obtained from germinal centers, the lymphocytes exhibited ultrastructural features of centroblasts and centrocytes. In a second type, likely derived from follicular mantles, the enclosed lymphocytes were small in size and characterized by a condensed chromatin pattern. Similar heterogeneity was observed by immuno-phenotypical analysis, which revealed a prevalence of IgD+, CD3-, MT2+ small lymphocytes in a high proportion of FDC-LC. Both types of FDC-LC contained desmoplakin immunoreactivity in a typical punctate pattern corresponding to intercellular junctions when tested with a specific antibody. These findings confirm the importance of FDC in maintaining the follicular structure and also suggest that the different zones forming lymphoid follicles (mantle zone and germinal center) are formed by lymphocytes gathered in single "domains" by cytoplasmic processes of FDC. These domains have strong resistance to mechanical stress, such as that used in isolation procedures. FDC-LC have also been maintained as organized multicellular clusters for short periods (more than 48 h) in agarose gel cultures.

Immunohistochemical characterization of osteoclasts and osteoclast-like cells with monoclonal antibody MB1 on paraffin-embedded tissues.

In this study we provide evidence that MB1, a newly developed monoclonal antibody which reacts with B lymphocytes and a proportion of T cells and monocytes, can be successfully used for the direct immunohistochemical identification of osteoclasts on paraffin-embedded surgical specimens. The antigen(s) recognized by MB1 is present at high density in the cytoplasm of osteoclasts of fetal bone and in the multinucleated cells of human giant cell tumour of bone (osteoclastoma), but is weakly expressed or absent in the giant cells of granulomas. MB1 is thus proposed as a new immunohistochemical marker for osteoclasts on paraffin-embedded material.

Distribution of melanoma specific antibody (HMB-45) in benign and malignant melanocytic tumours. An immunohistochemical study on paraffin sections.

The distribution of a recently produced melanoma specific antibody (HMB-45) has been evaluated histochemically on paraffin sections in a large panel of melanocytic and non melanocytic tumours. Results have been compared with the presence of S-100 protein. HMB-45 was shown to be a highly specific antibody being present only in melanomas, junctional melanocytes and histogenetically related neoplasms such as melanocytic neuroectodermal tumour of infancy and, at low levels, on a proportion of peripheral nerve sheath tumours. The high specificity of HMB-45 antibody, coupled with the greater sensitivity of S-100, makes the combined use of these markers practical in the differential diagnosis of skin tumours and of metastatic lesions of uncertain primary site.

Soluble interleukin-2 receptors in the sera of patients with hairy cell leukemia: relationship with the effect of recombinant alpha-interferon therapy on clinical parameters and natural killer in vitro activity.

In this study we provide evidence that the sera of patients with hairy cell leukemia (HCL) contain a factor that can prevent the binding of a monoclonal antibody specific for interleukin-2 receptor (IL-2R) to its target. This factor corresponds to the soluble form of IL-2R (sIL-2R), as assessed by a specific enzyme-linked immunosorbent assay test, and appears to be released by neoplastic hairy cells. The serum sIL-2R levels were very high at diagnosis and significantly reduced during recombinant alpha-interferon (rIFN alpha 2) therapy. Values of sIL-2R appeared to be inversely related to the natural killer in vitro function displayed by peripheral blood mononuclear cells from the same patients. The presence of sIL-2R in the serum of patients with HCL might be involved in the impairment of cell-mediated immunity observed in these patients and could represent a valuable marker for monitoring different phases of the disease and for modulating IFN therapy.

Immunohistochemical evidence of active thymocyte proliferation in thymoma. Its possible role in the pathogenesis of autoimmune diseases.

Eight cases of human thymoma have been analyzed on cryostat sections with the monoclonal antibody Ki67, which reacts with cells in the proliferative phases of the cell cycle. The aim was to assess the proportion of proliferating thymocytes among lymphoid cells in the thymoma samples. In all cases a large number of cells (mean, 58.75%; range, 35-80%), recognized as thymocytes by morphology and lack of cytokeratin expression in a combined immunohistochemical assay, exhibited nuclear Ki67 staining. These findings differ from the reactivity pattern observed in age-matched nonneoplastic thymuses where lower growth activity of cortical thymocytes was observed (15-20% Ki67+ cells). Intensive thymocyte proliferation in thymomas may represent one of the factors which lead to autoimmunity in myasthenia gravis and thymomas.

Mediastinal large-cell lymphoma with sclerosis. Genotypic analysis establishes its B nature.

The Southern blot hybridization technique has been applied to study the configuration of immunoglobulin and T-cell receptor genes in 6 cases of the so called mediastinal large cell lymphoma with sclerosis. This lymphoma has been recently recognized as a separate entity among non-Hodgkin lymphomas mainly affecting young adult patients. The B-cell origin of this neoplasm was suggested by means of immunohistochemical analysis. However, the immunophenotypical B-cell related markers used do not always exhibit lineage fidelity. The Southern blot analysis demonstrated the presence of unique heavy and k-light chain immunoglobulin gene rearrangements, establishing genotypically their B-cell origin.

Hyaline-vascular type of Castleman's disease (angiofollicular lymph node hyperplasia) with monotypic plasma cells. An immunohistochemical study with monoclonal antibodies.

A case of angiofollicular lymph node hyperplasia (Castleman's disease) characterized by monotypic (IgG+, lambda+) plasmacytosis is described. Fresh tissue was available and a thorough immunohistochemical analysis of lymphoid and non-lymphoid cells was performed on cryostat sections. Although lymphoid follicles were numerous and exhibited some abnormal features they did not appear part of the monoclonal cell proliferation. Follicular lymphocytes were mixtures of Kappa+ and lambda+ cells. Vessels penetrating within these abnormal follicles expressed reduced levels of FVIII and Leu-M5 antigens and exhibited thicker layer of collagen type IV. The analysis of T-cell subsets showed a normal (3:1) T4/T8 ratio. This case extends to the mixed variant of hyaline-vascular Castleman's disease, the neoplastic potential previously associated to the plasma cell variant of the disease.

Immunohistological analysis of Rosai-Dorfman histiocytosis. A disease of S-100 + CD1-histiocytes.

Five cases of Rosai-Dorfman histiocytosis (RDH) (also called Sinus Histiocytosis with Massive Lymphoadenopathy; SHML) have been studied by immunohistochemical methods with heteroantisera and monoclonal antibodies. One case was also studied by Southern blot hybridization analysis with DNA probes specific for T cell receptor beta chain and immunoglobulin heavy chain. Immunophenotyping of large histiocytes, characteristic of RDH, evidenced the presence of S-100 protein and the absence of CD1 and other markers usually found in histiocytes and macrophages. DNA hybridization study showed the absence of clonal T or B lymphoid populations.

Blastic OKT6-positive proliferation preceding malignant histiocytosis.

A 45-year old male presented latero-cervical lymphoadenopathy. Biopsy revealed a malignant proliferation of immature "lymphoid" cells bearing T6 antigen and HLA-DR but negative for other lymphoid markers, suggesting a phenotype similar to Langerhans cells. The patient did not receive any therapy and six months later developed a histologically typical malignant histiocytosis, involving spleen and liver. Other reported cases of lymphoid malignancies (two bearing the T6 antigen on blast cells) preceding malignant histiocytosis were found and compared with ours. Most of these cases were characterized by the pediatric age of the patients and were presented as acute leukemias exhibiting, in at least some of them, reliable T-cell markers. Our case appears to represent, on the other hand, a blastic proliferation of precursors of both histiocytes and Langerhans dendritic cells which eventually progressed to malignant histiocytosis. The relevance of this observation in the debate on the origin of Langerhans cells and the relationships existing between macrophages and dendritic cells is discussed.