p53 Mutations in nasal natural killer/T-cell lymphoma from Mexico: association with large cell morphology and advanced disease.

Nasal NK/T-cell lymphoma is a unique form of lymphoma highly associated with Epstein-Barr virus, and with a characteristic geographic distribution. Recently, we showed that p53 is overexpressed in a high percentage of nasal NK/T-cell lymphomas. The aim of this study was to analyze the status of the p53 gene, and correlate it with the expression of p53 protein and its downstream target, the cyclin-dependent kinase inhibitor p21, in a series of 25 cases of well-characterized nasal NK/T-cell lymphoma from Mexico. The highly conserved exons 5 to 8 of the p53 gene were amplified by polymerase chain reaction and screened for mutations by denaturing high-pressure liquid chromatography. Abnormal polymerase chain reaction products detected by denaturing high-pressure liquid chromatography and additional selected cases were sequenced. In addition, the incidence of loss of heterozygosity at the p53 locus was analyzed in 12 cases. Of the 25 patients, 17 were male and 8 female (M:F ratio, 2.1:1), with a median age of 43 years (range, 21 to 93 years). Morphologically, most of the cases were composed of a mixture of medium-sized cells and large transformed cells (21 cases), and four cases were composed exclusively of large transformed cells. Three different groups determined by p53 gene status and expression of p53 protein were identified: group 1 was p53 +/p53 mutated (five cases, all with p53 missense mutations). Morphologically, three of the five cases were composed of large cells. All five cases revealed overexpression of p53 in the majority of the tumor cells with a mean of 86%. Unexpectedly, three of these cases also showed overexpression of p21. Four of the five patients presented with clinical stage IVB and died with disease. Group 2 was p53+/p53 wild-type (10 cases). Histologically, nine cases were of the mixed type, and one of the large cell type. The percentage of p53 overexpressing cells was lower than in the previous group with a mean of 23%. p21 was positive in 7 of the 10 cases. Six patients in this group presented with clinical stages I to II and four patients with advanced disease (stage III and IV). Five patients are alive 12 to 120 months later (mean, 24 months), three with no evidence of disease. Group 3 was p53-/p53 wild-type (10 cases). All cases showed mixed cell morphology. p21 was positive in 5 of 10 cases. Four patients presented with clinical stage I to II and six patients with advanced disease. Four patients are alive with no evidence of disease 9 to 60 months later (mean, 10 months). Overall, p53 mutations were present in 24% (5 of 21) of the evaluable cases, all of them overexpressing p53 in the majority of tumor cells. Cases with p53 mutations were associated with large cell morphology (P = 0.0162) and presented more often with advanced stage disease. Loss of heterozygosity at chromosome 17p was found only in 2 of the 12 (17%) cases investigated, both cases showed p53 mutations of the remaining allele. P21 overexpression (60% of cases) is frequent in nasal NK/T-cell lymphoma and seems to be independent of p53 gene status. The overexpression of p53 and p21, independent of p53 mutations, although as yet not clear, might be the result of Epstein-Barr virus infection, and warrants further investigation.

High prevalence of a 30-base pair deletion in the Epstein-Barr virus (EBV) latent membrane protein 1 gene and of strain type B EBV in Mexican classical Hodgkin's disease and reactive lymphoid tissue.

Depending on geographic location and patient age Hodgkin's disease (HD) is associated with Epstein-Barr virus (EBV), mostly type A EBV, in 20% to 100%. The highest prevalence occurs in children of developing countries. Molecular analysis of the oncogene coding for the latent membrane protein 1 (LMP-1) revealed a 30-base pair (bp) deletion in up to 46% of EBV-positive HD. We investigated the presence of EBV in a series of Mexican classical HD (n = 57) and reactive lymphoid tissues (n = 20) from a private and a public hospital with special emphasis on the prevalence of the 30-bp deletion and the type of EBV. EBV infection was analyzed at the cellular level by Epstein-Barr encoded early RNA transcripts (EBER) in situ hybridization (ISH) and by LMP-1 protein immunohistochemistry (IHC). Molecular analysis of the LMP-1 gene configuration was performed by polymerase chain reaction (PCR) with primers spanning the site of the deletion and subsequent Southern and/or dot blot hybridization using wild-type and deletion-specific probes. The prevalence of type A and type B EBV was investigated by PCR-analysis for divergence in the coding region of Epstein-Barr nuclear antigen (EBNA)-2. EBV was detected in Hodgkin- and Reed-Sternberg cells (H-RS) by LMP-1 IHC and/or EBER ISH in 35/57 (61%) Mexican HD including 18/32 (56%) with nodular sclerosis, 15/20 (75%) with mixed cellularity and 2/4 (50%) with lymphocyte depletion. In addition, LMP-1 gene sequences were detected by PCR in 9 cases of HD without LMP/EBER expression by H-RS cells and in 17/20 (85%) reactive lymph nodes, supposedly originating from rare latently infected B cells. Surprisingly, the 30-bp LMP-1 deletion was found in 28/35 (80%) EBV-positive HD. This deletion, however, was also found in all 9 (100%) HD with H-RS cells negative for EBV and in 10/17 (59%) reactive lymph nodes. Thus, the overall LMP-1 del prevalence in reactive tissue is 73% (19/26). Typing of EBV was successful in 26 cases of EBV-positive HD, 10 of these were infected by type B EBV (38%). Of the reactive lymphoid tissue, 9 (47%) were infected by type A, and 10 (53%) by type B; All 20 cases (100%) associated with type B, whether neoplastic or reactive, displayed the LMP-1 del variant compared with 18/25 (72%) infected by type A EBV. To our knowledge, this is the highest incidence for both the LMP-1 deletion variant and the infection by type B EBV in HD reported so far worldwide. Our data suggest that EBV infection contributes to the pathogenesis of the majority of Hodgkin's disease cases in Mexico. The specific tumorigenic role of the LMP-1 deletion variant, however, is doubtful with regard to its high frequency in nonneoplastic lesions. Moreover, type B infection frequently occurs in Mexican HD and reactive lymphoid tissue and is consistently associated with the deletion variant pointing to a pathogenetic role of this combined genotype.

Histological and immunophenotypic profile of nasal NK/T cell lymphomas from Peru: high prevalence of p53 overexpression.

Nasal NK/T-cell lymphoma is a unique form of lymphoma highly associated with Epstein-Barr virus (EBV). These lymphomas are rare in Western populations and much more prevalent in some Asian and Latin American countries. Although there are several sizable studies from Asian countries, the same is not true from South America. The aim of this study was to analyze a series of 32 cases of nasal T-cell lymphoma from Peru and to further extend the characterization of this disease. Immunohistochemistry was performed on paraffin sections using the following antibodies: CD20 (L26), CD45RO, CD3, Ki67, CD57, CD56, TIA-1, bcl-2, and p53. The presence of EBV was investigated with immunohistochemical analysis for latent membrane protein (LMP)-1 and in situ hybridization using an antisense riboprobe to EBER 1. The 32 patients included 18 men and 14 women (M:F ratio, 1.2:1), with a median age of 43 years (11 to 72). Three categories were identified: (1) Nasal NK/T cell lymphomas (28 cases): The morphology ranged from small or medium-sized cells to large transformed cells. Necrosis was present in 86% of the cases, and angioinvasion was seen in 36% of the cases. All cases were positive for CD45RO, CD3, and for TIA-1. CD56 was positive in 21 of 27 cases (78%), and CD57 was negative in all cases. EBER 1 positivity was identified in most of the tumor cells in 27 of 28 cases (96%), including the six cases in which CD56 was negative. Overexpression of p53 was detected in 24 cases (86%). (2) Blastic NK cell lymphoma (1 case): The neoplastic cells resembled those of lymphoblastic lymphoma. CD56 and CD45RO were positive; TIA-1, TdT, and EBER-1 were negative. (3) Peripheral T-cell lymphoma (PTCL) unspecified (3 cases): CD56, TIA-1, and EBER-1 were negative. Nasal lymphomas from Peru with a T cell phenotype are predominantly EBV-associated NK/T cell lymphomas, similar to those described in Asian countries. The expression of CD56, TIA-1, and EBER-1, in combination, are very useful markers for the diagnosis of nasal NK/T cell lymphoma in paraffin-embedded tissue. The differential diagnosis of T-cell lymphomas in the nasal region should include rare cases of PTCL unspecified and the blastic variant of NK cell lymphoma. P53 is overexpressed in 86% of the cases. The significance of this finding with regard to clinical behavior and prognosis remains to be determined.

Primary intestinal non-Hodgkin's lymphoma and Epstein-Barr virus: high frequency of EBV-infection in T-cell lymphomas of Mexican origin.

Epstein-Barr virus is universally associated with endemic Burkitt's lymphoma (BL) and undifferentiated nasopharyngeal carcinoma and can be detected in a significant proportion of cases of Hodgkin's disease (HD) and peripheral T-cell lymphoma, but only rarely in sporadic B-NHL. The frequency of EBV-positivity in certain neoplasms shows important geographic variations. Both HD and sporadic BL from Latin America have shown higher rates of EBV-association than cases from Western countries. In T-NHL, the frequency of EBV-positivity is influenced by the site of the primary tumor and the phenotype of the neoplastic cells. Nasal and nasal-type T-NHL, which show a T/NK-cell phenotype with expression of CD56 are virtually always EBV-associated, whereas only a proportion of nodal, gastrointestinal and pulmonary T-NHL are EBV-infected. A recent investigation of primary intestinal lymphomas of Mexican origin demonstrated EBV-positivity in all examined cases of T-NHL and BL and a proportion of other B-NHLs. The presence of EBV was independent of the presence or absence of enteropathy. Two of 6 cases studied showed CD56 expression. The high rate of EBV-positivity independent of histologic subtype is in contrast to the low to intermediate rates of EBV-positivity found in cases of intestinal T-NHL from Western countries and indicates that geographic differences in the frequency of EBV-association of lymphoid neoplasms might also extend to a fraction of peripheral T-cell lymphomas.

Post-transplantation lymphoproliferative disorders in Mexico: an aggressive clonal disease associated with Epstein-Barr virus type A.

Post-transplantation lymphoproliferative disorders (PT-LPDs) are a complication of immunosuppression with variable clinical behavior and frequent Epstein-Barr virus (EBV) association. There is geographic variation in the association of EBV with certain tumors and a lack of studies of PT-LPDs from developing countries, so we decided to study in detail a series of PT-LPDs from Mexico to identify similarities and differences between populations in Mexico and those in Europe and the United States. We used paraffin-embedded tissue from eight PT-LPDs (six from men, two from women) that arose after renal transplantation. Clinical data, morphologic features, and clonality on the basis of immunoglobulin (Ig) light chain restriction, as well as polymerase chain reaction (PCR) for Ig heavy chain genes, were studied. The presence of EBV was investigated with PCR, immunohistochemical analysis for latent membrane protein (LMP)-1, and in situ hybridization for EBV early RNA transcripts. In addition, the subtype of EBV based on the EBNA 2A and 2B genes and the presence of a 30-bp deletion in the LMP-1 gene were investigated by PCR. Seven (87.5%) of eight cases presented with gastrointestinal involvement; five patients died. Three cases were polymorphic PT-LPDs, four were monomorphic large cell lymphomas (one diffuse large cell, three immunoblastic), and one was unclassifiable. All showed a B-cell phenotype, with a clonal population demonstrated in seven of the eight cases. Tumor cells expressed EBERs in all of the cases and LMP-1 in six of seven evaluable cases. Seven of seven cases showed EBV subtype A. Two (25%) of eight cases had the 30-bp LMP-1 deletion. This study shows that PT-LPDs in Mexico are clonal disorders associated with EBV subtype A. In contrast to series from Europe and the United States, our cases showed a significantly higher incidence of gastrointestinal tract involvement (P < .001), and a lower incidence of the 30-bp LMP-1 deletion, although this was not statistically significant (P < .28).

Primary non-Hodgkin's lymphoma of the intestine: high prevalence of Epstein-Barr virus in Mexican lymphomas as compared with European cases.

Recent studies in Western European populations have shown that peripheral T-cell non-Hodgkin's lymphomas (T-NHLs) are associated with Epstein-Barr virus (EBV) in a higher percentage than sporadic B-cell NHL (B-NHLs), and that the frequency of EBV-positivity might be influenced by the primary site of the tumor. Because of the geographic differences in EBV expression in Burkitt's lymphoma (BL) and Hodgkin's disease (HD), and the lack of studies of sporadic NHL from developing countries, we decided to survey the presence of EBV in a series of primary intestinal lymphomas from patients in Mexico and in Western Europe, and to analyze whether EBV status is influenced by tumor phenotype, and geographic or ethnic determinants. Paraffin-embedded tissue from 43 primary intestinal NHLs (19 cases from Mexico and 24 from Western Europe) were examined, including 17 high grade B-NHLs, 9 low grade B-NHLs, and 17 T-NHLs; 6 of which were enteropathy associated T-cell lymphomas. The distribution of histologic subtypes was similar in both groups. The presence of EBV was investigated with a combined approach using a nested polymerase chain reaction technique as well as immunohistochemistry for latent membrane protein-1 and in situ hybridization for EBV early RNA transcripts (EBER 1/2) RNAs. The median age of the Mexican patients was significantly lower than the median age of the European patients (32 v 62 years). This difference was most pronounced in patients with T-cell lymphoma (24 v 63 years). EBER-positive tumor cells were detected in 13 of the 43 (30%) cases of primary intestinal lymphoma, including 5 of 26 sporadic B-NHL (3 high grade and 2 low grade), and 8 of 17 T-NHL, all of which were classified as pleomorphic, medium and large cell. The rates of EBV-positivity were markedly different for European and Mexican cases. Whereas 7 of 7 (100%) T-NHL and 5 of 12 (42%) sporadic B-NHL of Mexican origin were EBER-positive, only 1 of 10 T-NHL and 0 of 14 sporadic B-NHL from Europe showed EBER expression in tumor cells. Latent membrane protein was positive in only 2 of 43 cases, 1 of which was an EBER-negative high grade B-NHL from Mexico that showed intact total mRNA in control hybridization. CD30 expression was found in 4 of 8 EBV-positive T-NHL and in none of the EBV-positive B-NHL. In contrast to European cases, intestinal NHLs from Mexico show a very high frequency of EBV-positivity, which is not limited to T-NHL, but includes a significant proportion of B-NHL. This study strongly suggests that similar to HD and probably BL, there are important epidemiologic differences in EBV association in intestinal T-cell NHL between European and Mexican populations. These differences might be the result of environmental factors, for example, earlier contact with childhood viruses on intestinal lymphomagenesis.

[Pancreatoduodenectomy in the treatment of carcinoma of Vater's ampulla]. / Pancreatoduodenectomía en el tratamiento de carcinoma del ámpula de Vater.

OBJECTIVE: To analyze clinical characteristics, diagnostic methods, intraoperative findings, morbidity & mortality and outcome of a series of patients with ampullary adenocarcinoma. DESIGN: Retrospective analysis. SETTING: Tertiary-care medical center. PATIENTS: Thirty four consecutive patients who underwent radical resection between 1960 and 1992. RESULTS: The most frequent findings were jaundice (91%), weight loss (44%) and palpable gallbladder (42%). Thirty-three patients (97%) underwent Whipple resection and one total pancreatectomy (3%). The postoperative mortality was 15%. Overall survival at 1, 5, 10 and 14 years was 67, 36, 25 and 17% respectively. Fourteen patients died of tumor recurrence developed more than five years after the resection. CONCLUSION: Radical resection for ampullary carcinoma remains the procedure of first choice in these patients.

Association of Epstein-Barr virus latent membrane protein and Hodgkin's disease in Mexico.

Epstein-Barr virus (EBV) has been demonstrated in association with Hodgkin's disease (HD) in approximately 40 to 50% of cases in series from North America, Europe, and Japan. However, few data are available concerning this association in developing countries. Recent studies, including mostly a pediatric population from Peru and a pediatric population from Honduras, showed a higher percentage of EBV positivity compared with those in developed countries. To determine the prevalence of EBV in Hodgkin's disease in a Mexican adult population, we analyzed 50 formalin-fixed, paraffin-embedded cases of HD by a three-step technique using a monoclonal antibody to the latent membrane protein of EBV. All the cases were confirmed immunophenotypically as HD (CD15+ and/or CD30+, CD45-). Reed-Sternberg cells and variants were positive for LMP in 35 cases (70%). The staining was found both on the cell surface and/or within the cytoplasm with enhancement of the Golgi area. EBV latent membrane protein was found in 1/1 case (100%) of diffuse lymphocyte-predominant HD, 10/20 cases (50%) of nodular-sclerosis, 18/22 cases of mixed-cellularity (81%), and 6/7 (86%) cases of lymphocyte-depleted HD. Our results show a high prevalence of EBV in HD in this Mexican adult population. All histologic subtypes of HD in the population analyzed appear to be strongly associated with EBV, in contrast to the strong association of mixed cellularity HD in developed countries. Patient age and gender were not predictive of the presence of EBV.

[Hepatitis C virus infection and membranoproliferative glomerulonephritis]. / Infección por virus de la hepatitis C y glomérulonefritis membranoproliferativa.

BACKGROUND AND METHODS: A possible association between hepatitis C virus infection (HCV) and membranoproliferative glomerulonephritis (MPGN) or membranous glomerulonephritis has recently been reported. The pathogenesis of this entity appears to be immunologically mediated. The purpose of this report is to describe the clinical, laboratory, and histopathological features of three patients with chronic HCV infection, without hepatitis B virus disease or autoimmune diseases, but with glomerular disease. RESULTS: All three patients had chronic hepatopathy stigmata, ascitis, peripheral edema, and normal blood pressure values. Laboratory results showed mild liver function abnormalities and normal levels of blood nitrogenous waste products. Microscopic hematuria, hypoalbuminemia, and variable proteinuria without hypercholesterolemia were found in all cases. All three had positive rheumatoid factor. Only one patient had positive antinuclear antibodies and antimitochondrial antibodies at low levels, and another displayed low C3 and C4 serum levels. Renal histology in the three cases showed type I membranoproliferative glomerulonephritis and hepatic cirrhosis in the liver biopsy. CONCLUSIONS: This report supports the association between chronic HCV infection and membranoproliferative glomerulonephritis. However, further studies are needed to establish more firmly the association as well as the mechanisms of pathogenesis and causality between them.

[Lymph node biopsy using fine-needle aspiration. Clinical and cytohistological correlation in 179 cases]. / Biopsia de ganglio linfático por aspiración con aguja delgada. Correlación clínica y citohistológica en 179 casos.

We reviewed the institutional experience with fine needle aspiration biopsy (FNAB) of peripheral lymph nodes in the Instituto Nacional de la Nutrición Salvador Zubiran from January 1988 to December 1992. A total of 298 FNAB had been performed in 288 patients. Aspirates with just blood, few stromal cells or with desiccation changes were excluded (63 cases), as well as those in whom it was not possible to establish a clinical or morphologic correlation (56 cases). In the 179 cases included, the FNAB diagnosis was histologically confirmed in 137 and in 42 cases the correlation was established by clinical follow-up and response to treatment. According to the diagnosis, aspirates were divided in benign and malignant in the analysis. We observed 70 aspirates (39%) with benign lesions and 109 (61%) with primary or metastatic neoplastic cells. The most frequent benign diagnosis was hyperplasia followed by epithelial metastatic neoplasms. In 25 aspirates there was a discrepant cyto-histologic diagnosis but only six were false negatives. No false positive or complications were identified. The FNAB in our cases showed: sensitivity 95%, specificity 100%, positive predictive value 100% and negative predictive value 91.4%. Our data support the value of FNAB as a reliable, safe, inexpensive and easy to perform method in the diagnosis of lymph node enlargements. Thus, we believe this method should be recommended as the initial approach in the study of lymphadenopathies.

[High prevalence of the Epstein-Barr virus in a Mexican population with Hodgkin's disease]. / Prevalencia alta del virus de Epstein-Barr en una población mexicana con enfermedad de Hodgkin.

The Epstein-Barr virus (EBV) has been demonstrated in association with cases of Hodgkin's disease (HD) indicating that, in at least in some cases, EBV may play a pathogenic role in the development of HD. To determine the prevalence of EBV in HD in a Mexican adult population, we studied 39 formalin-fixed and/or B-5, paraffin embedded samples of patients with HD, by immunoperoxidase; in situ hybridization was done in 32 of the 39 cases. We analyzed the presence of the latent membrane protein (LMP) and EBV-specific DNA sequences. Reed-Sternberg cells and mononuclear variants were positive for LMP in 28 cases (72%). LMP staining was found both on the cell surface and/or within the cytoplasm with enhancement in the Golgi area. The LMP was found in the single case of diffuse lymphocyte predominant HD, in 6/12 cases of nodular sclerosis (50%), in 10/15 cases of mixed cellularity (67%) and in all eleven cases of lymphocyte depleted HD (100%). No EBV-specific DNA sequences were found by in situ hybridization. Our results show: 1) a higher association of EBV in our population compared to the approximately 48% reported in developed countries; 2) all histologic subtypes of HD in Mexico appear to be strongly associated with EBV in contrast to the strong association with only mixed cellularity seen in Western populations; 3) the high prevalence of EBV in HD in Mexico may be a function of histology, ethnic groups, socioeconomic factors and/or geography.

[Clinico-pathological diagnostic agreement among 429 autopsies from the Instituto Nacional de la Nutrición Salvador Zubirán]. / Concordancia diagnóstica clinico-patológica en 429 autopsias del Instituto Nacional de la Nutrición Salvador Zubirán.

Comparison of clinical and autopsy findings of the cases studied between 1984 and 1988, were made at the Department of Pathology of the Instituto Nacional de la Nutricion Salvador Zubiran in Mexico City. The goal was to determine the accuracy of clinical diagnoses. The total number of cases was 429. A decreasing number of autopsies as a function of time was observed. Thus, in 1985, 34.65% of the deaths was autopsied, whereas in 1988, the number dropped to 21.16%, overall mean of 27.31%. In 229 autopsies (53.8%), 353 findings of clinical significance were found; of these, 86 were in the main diagnoses and 267 in the causes of death. There were 171 overdiagnoses with therapeutic implications, 38 in the main diagnoses and 133 in the causes of death. Overdiagnoses and underdiagnoses were most common in infectious diseases, followed by respiratory and digestive diseases, while endocrinologic and rheumatologic diseases had the highest diagnostic concordance. It was also found that the diagnostic accuracy did not improve with time of hospitalization. A brief analyses of the probable causes of the decrease in the number of autopsies is made. It is concluded that, in spite of the great advances in clinical and technological knowledge, the high frequency of disagreements between clinical and anatomical diagnoses, indicate that autopsy continues playing a key role in the quality control of medical practice. This justifies by itself the performance of necropsies.

Primary carcinoid of the common bile duct. Immunohistochemical characterization of a case and review of the literature.

A 39-year-old woman with a primary carcinoid of the common bile duct is presented. The tumor showed argyrophilia; and, by immunohistochemical studies, chromogranin, serotonin, and somatostatin were demonstrated. The patient has no symptoms 42 months after surgical treatment. To the authors' knowledge, this is the first report of a carcinoid of the common bile duct as studied by immunohistochemistry. When six choledochal carcinoids were reviewed, the following characteristics were observed: in none of the cases were endocrine symptoms present; women were affected more frequently than men; the carcinoids occurred in younger patients than did adenocarcinomas; metastases were present in half of the patients; and, as a group, carcinoids seemed to have a better prognosis than adenocarcinomas in this location.

[Xanthogranulomatous cholecystitis. Clinical entity or pathologic curiosity]. / Colecistitis xantogranulomatosa. Entidad clínica o curiosidad patológica.

Xanthogranulomatous cholecystitis is an uncommon variety of gallbladder inflammation. Its histologic appearance is quite specific but its clinical characteristics, prognostic and physiopathologic implications are unknown. The present study has the aim of analyzing a group of 40 patients with xanthogranulomatous cholecystitis and another of 80 patients with non-xanthogranulomatous inflammation. The clinical characteristics, risk factors, morphologic expression, complications and mortality of both groups were compared. Diffuse xanthogranulomatous cholecystitis comprised 1.8% of all cholecystectomies done between January 1976 and July 1987. This variety was more frequent in males (p less than .05) without any specific risk factors. There was a higher frequency of acute pyogenic inflammation sometimes associated to extrinsic compression of the biliary duct and fistulization, but without any difference in the overall complication rate or mortality. We conclude that xanthogranulomatous cholecystitis is a specific entity which occurs with a higher frequency in males and that has a different clinical behavior than that of other types of gallbladder inflammation.