Detection of Epstein-Barr virus DNA in formalin-fixed paraffin-embedded tissue of nasopharyngeal carcinoma using polymerase chain reaction and in situ hybridization

Thymic Lymphoepithelial Carcinoma Associated with Epstein-Barr Virus: Experiences and Literature Review

Thymic lymphoepithelial carcinoma (TLEC) is a primary thymic carcinoma that accounts for about 14% of all thymic epithelial tumors and is classified into 14 types. The histological morphology is similar to lymphoepithelioma, a type of undifferentiated nasopharyngeal carcinoma. It has been reported that squamous carcinoma accounts for approximately 80% of thymic carcinoma, followed by TLEC, which accounts for 6%. TLEC has been reported to be associated with Epstein-Barr virus (EBV), with EBV infection in TLEC tumor cells first noted by Lyvraz et al. in 1985. Tumors shown to be EBV-positive are classified as TLEC if lymphoplasmacytic infiltration is lacking. However, only about 50% of the cases are positive for EBV, which is lower compared to nasopharyngeal lymphoepithelioma. Instances of EBV infection in other types of thymic epithelial tumor have been reported at lower rates, which suggests that EBV infection may have an important influence on the carcinogenesis of TLEC, though the etiology is unknown. TLEC is a highly malignant tumor with poor prognosis, as affected patients have a median survival time of 22 months, according to 58 cases from the literature, while the 5-year survival rate is 34.4%. Presently, prognosis is not considered to be affected by the presence or absence of EBV positivity.

Pathobiology of selected tumors of the base of the skull

Skull base surgery is a new subspeciality, and, up to this point, most articles on this subject have focused on innovative operative-reconstructive approaches to tumors in this region. It is now important that we embark on a new era, the era of tumor biology, and concentrate on new ways of evaluating these neoplasms from a pathologic viewpoint. The hematoxylin-cosin section is no longer an end point, but just a beginning. This is the age of molecular biology. It is important that these tumors be evaluated, either prospectively or retrospectively, employing immunohistochemical staining, flow cytometry, oncogene expression, cytogenetics, or other techniques in order to identify important prognostic features. Data from these additional studies may then be used to develop new treatment strategies. Skull base societies should develop protocols for one or more of these tumors to ensure that they are indeed evaluated uniformly. In this article I emphasize the importance of accurate histologic classification or subclassification of these neoplasms and focus on contemporary parameters that may or may not impact on prognosis.

The incidence of Epstein-Barr virus in nasopharyngeal carcinoma of Jordanian patients

Aim of this study was to investigate the incidence of Epstein-Barr virus (EBV) in patients diagnosed with undifferentiated nasopharyngeal carcinoma (UNPC) from the Northern Province of Jordan. All cases diagnosed with UNPC at King Abdullah University Hospital, Irbid, Jordan, between the years 1991 and 2009 inclusive were examined. Clinical data including age, gender, mode of presentation, site of biopsy were retrieved from pathology reports. In situ hybridization for (EBV)--EBERs was performed on cases with available paraffin blocks. Correlation between the different clinical variables and results of in situ hybridization was performed. There were 49 cases diagnosed with UNPC, only 39 specimens were available and studied. The median age of presentation was 41 years (range 9-70 years). Bimodal age distribution was noted, the first peak between 15 and 19 years of age and second between 60 and 64 years of age. Males were slightly more commonly affected than females. Cervical lymph node enlargement was the most common mode of presentation, followed by nasal obstruction. Biopsies were obtained primarily from the posterior nasal space, followed by cervical lymph node. Positive staining for EBERs by in situ hybridization was seen in 92.3% of the cases examined. There was no difference in detection rate between males and females or adults and pediatrics. All cases obtained from posterior nasal space were positive. The three negative cases were from biopsies obtained from cervical lymph nodes, which was statistically significant (P value <0.05). Nasopharyngeal carcinoma in Jordan is seen in both children and adults. It is associated with EBV infection in most, but not all cases. Posterior nasal space shows a more consistent staining for EBERs than cervical lymph nodes. The presence of other association with UNPC including cigarette smoking could possibly explain the cases with negative association.

Simple salting-out method for DNA extraction from formalin-fixed, paraffin-embedded tissues

The aim of this study was to standardize a method of DNA extraction from formalin-fixed and paraffin-embedded tissues (PETs) using a salt solution to precipitate protein and isopropanol to precipitate DNA. The samples were submitted to a DNA extraction method in which two different concentrations of ammonium acetate (2 and 4M) were compared with a phenol-chloroform extraction method and with a commercial DNA isolation kit. DNA was qualified and quantified by spectrophotometer analysis, electrophoresis, and amplification by PCR. The 167 and 268bp fragments of APC and beta-globin genes, respectively, were amplified equally from DNA extracted by all tested methods and in all cases. However, the 536bp fragment of beta-globin gene was not amplified in all cases. According to our results, the extraction method using ammonium acetate proved to be simple and suitable for obtaining DNA of good quality, which can be easily amplified by PCR.

Expression of Epstein-Barr virus-encoded small nuclear RNA 1 in Japanese nasopharyngeal carcinomas

An examination was made of the incidence of the Epstein-Barr virus (EBV) genome and its exact localization in 39 cases of nasopharyngeal carcinoma (NPC) in Japanese patients by means of in situ hybridization (ISH) with a digoxigenin-labeled Epstein-Barr virus-encoded small nuclear RNA 1 (EBER1) oligonucleotide probe. Hybridization signals were observed in the nucleus of tumor cells in all 39 NPCs, including keratinizing carcinomas. The signals varied greatly in intensity from case to case and even from cell to cell in the same tumor, but were recognized in most tumor cells in each case. Signals could occasionally be seen in limiting number of infiltrating small lymphocytes but were absent in all tumors of the tongue, midpharynx and hypopharynx. Combined immunohistochemistry-ISH studies indicated that EBER1 signals were restricted to tumor cells positive for cytokeratin. As a result of this study, it is now possible to perform large-scale retrospective analyses using routine formalin-fixed, paraffin-embedded tissue sections and to combine ISH for the EBV genome with immunohistochemistry for cytokeratin to determine the epithelial features of EBV genome-possessing cells. All NPCs were clearly shown to be EBV-infected, thus indicating that EBV is essential for the oncogenesis of NPCs.

Epstein-Barr virus LMP2A interferes with global transcription factor regulation when expressed during B-lymphocyte development

Epstein-Barr virus (EBV) is associated with the development of malignant lymphomas and lymphoproliferative disorders in immunocompromised individuals. The LMP2A protein of EBV is thought to play a central role in this process by allowing the virus to persist in latently infected B lymphocytes. We have demonstrated that LMP2A, when expressed in B cells of transgenic mice, allows normal B-cell developmental checkpoints to be bypassed. To identify cellular genes targeted by LMP2A that are involved in this process, we have utilized DNA microarrays to compare gene transcription in B cells from wild-type versus LMP2A transgenic mice. In B cells from LMP2A transgenic mice, we observed decreased expression of many genes associated with normal B-cell development as well as reduced levels of the transcription factors that regulate their expression. In particular, expression of the transcription factor E2A was down-regulated in bone marrow and splenic B cells. Furthermore, E2A activity was inhibited in these cells as determined by decreased DNA binding and reduced expression of its target genes, including the transcription factors early B-cell factor and Pax-5. Expression of two E2A inhibitors, Id2 and SCL, was up-regulated in splenic B cells expressing LMP2A, suggesting a possible mechanism for E2A inhibition. These results indicate that LMP2A deregulates transcription factor expression and activity in developing B cells, and this likely allows for a bypass of normal signaling events required for proper B-cell development. The ability of LMP2A to interfere with B-cell transcription factor regulation has important implications regarding its role in EBV latency.

Comparison of the DNA extraction methods for polymerase chain reaction amplification from formalin-fixed and paraffin-embedded tissues

To obtain an adequate quality and quantity of DNA from formalin-fixed and paraffin-embedded tissue, six different DNA extraction methods were compared. Four methods used deparaffinization by xylene followed by proteinase K digestion and phenol-chloroform extraction. The temperature of the different steps was changed to obtain higher yields and improved quality of extracted DNA. The remaining two methods used microwave heating for deparaffinization. The best DNA extraction method consisted of deparaffinization by microwave irradiation, protein digestion with proteinase K at 48 degrees C overnight, and no further purification steps. By this method, the highest DNA yield was obtained and the amplification of a 989-base pair beta-globin gene fragment was achieved. Furthermore, DNA extracted by means of this procedure from five gastric carcinomas was successfully used for single strand conformation polymorphism and direct sequencing assays of the beta-catenin gene. Because the microwave-based DNA extraction method presented here is simple, has a lower contamination risk, and results in a higher yield of DNA compared with the ordinary organic chemical reagent-based extraction method, it is considered applicable to various clinical and basic fields.

Oncocytic papillary carcinoma with lymphoid stroma (Warthin-like tumour) of the thyroid: a distinct entity with favourable prognosis

AIMS

We report the clinicopathological and immunohistochemical characteristics of 12 cases of a recently recognized entity, oncocytic papillary thyroid carcinoma (PC) with lymphoid stroma (Warthin-like tumour).

METHODS AND RESULTS

The cases were retrieved from the surgical pathology files of our departments. There were 11 female patients and one male patient; they ranged in age from 45 to 85 years (mean 64.2 years). The immunohistochemical profile demonstrated positivity of tumour cells for cytokeratins, thyroglobulin, Leu-M1 and anti-mitochondrial antigen. S100 protein-positive stromal dendritic/Langerhans cells were uniformly present. Polymerase chain reaction, in situ hybridization, and immunohistochemistry for Epstein-Barr virus (EBV) detection revealed no significant positive signal. MIB-1 labelling index was low, compatible with that of 'classical' PC.

CONCLUSIONS

Warthin-like tumour is a rare variant of PC, occurring predominantly in elderly women. Its histological features are distinct and well recognizable, differentiating this tumour from a more aggressive tall-cell variant of PC. The apparent indolent behaviour seems to be consistent with the presence of dendritic/Langerhans cells and with low proliferative activity. A possible role of EBV in pathogenesis of this lesion was not proven. Further studies are necessary to determine the prognosis and metastatic potential of this neoplasm.

Epstein-Barr virus early ribonucleic acids as a diagnostic adjunct for relapsed metastatic tumors in patients with cured primary undifferentiated nasopharyngeal carcinoma

PURPOSE

Epstein-Barr virus (EBV) has been consistently shown to be associated with undifferentiated nasopharyngeal carcinoma (NPC). In this article, the authors attempt to detect Epstein-Barr virus in distant relapsed metastatic sites in undifferentiated NPC patients with cured primary cancer.

MATERIALS AND METHODS

In situ hybridization (ISH) technique is a reliable method to detect EBV early RNAs (EBERs) within NPC cells. We used a nonisotopical ISH technique to examine the presence of EBERs in paraffin-embedded tissues obtained from 1 paired specimen of primary NPC and its metastatic counterpart at liver and 2 metastatic specimens of retroperitoneal lymph nodes and bone.

RESULTS

All the primary lesions and the metastatic tumors of NPC with undifferentiated histology contained EBERs that could be clearly detected in the nuclei of cancer cells.

CONCLUSIONS

This article shows that EBERs can be successfully detected in cells of the distant relapsed metastatic sites. These results suggest that this nonisotopical ISH method of EBERs can be potentially used to diagnose NPC patients developing distant relapsed metastatic lesions with cured primary cancer early. It can offer quick information as to institute suitable salvage chemotherapy for these patients.

Absence of nuclear p16 from Epstein-Barr virus-associated undifferentiated nasopharyngeal carcinomas

OBJECTIVE

Epstein-Barr virus (EBV) is detected in the majority of undifferentiated nasopharyngeal carcinomas (UNPCs, World Health Organization type III). However, the exact mechanism involved in the carcinogenesis of EBV-associated UNPCs remains to be elucidated. An important unresolved question is: how is the normal cell cycle deregulated during EBV-associated UNPC development? The p16CDKN2 gene encodes a nuclear protein, p16, which inhibits the D-type cyclin/cyclin-dependent kinase complexes that phosphorylate the retinoblastoma gene product (pRb), thus blocking G1 cell cycle progression. The objective of this study was to determine whether p16 absence is involved in the development of EBV-associated UNPCs.

METHODS

We performed immunohistochemistry to detect p16 and pRb and in situ hybridization to detect EBV-encoded small RNA (EBER) in UNPCs from 28 patients.

RESULTS

No p16 was detected in 23 of 28 UNPCs (82.1%), whereas pRb was expressed in all those examined and EBER was detected in 22 of 28 (78.6%). The absence of p16 was associated with the presence of EBER in UNPCs (P < .0001): none of the 22 EBER+ UNPCs expressed p16, whereas 5 of 6 EBER- UNPCs did.

CONCLUSION

Our data suggest that loss of p16-related cell cycle regulation plays an important role in the development of EBV-associated UNPCs.

Nasopharyngeal carcinoma

Nasopharyngeal carcinoma represents a morphologic spectrum of neoplasms localized to the nasopharynx and arising from nasopharyngeal epithelium. Nasopharyngeal carcinomas have rather unique clinical, epidemiologic, pathologic, and biologic features. The morphologic spectrum of nasopharyngeal carcinoma includes keratinizing, nonkeratinizing, and undifferentiated subtypes. The separation of these morphologic types is not an academic exercise, but has practical importance relative to differential diagnosis, management, and prognosis. A similar morphologic classification applies to carcinomas arising in the palatine tonsils and the base of tongue. The nasopharynx, palatine tonsils, and base of tongue are collectively designated as Waldeyer's tonsillar tissues. Awareness of the morphologic spectrum of Waldeyer's ring carcinomas may assist in suggesting the primary tumor site in the face of an occult metastatic carcinoma to cervical neck lymph nodes.

Epidemiological research into nasopharyngeal carcinoma in the Chubu region of Japan

Although patient death due to nasopharyngeal carcinoma (NPC) is increasing, few epidemiological analyses of NPC in Japan have been conducted since Sawaki's report in 1979. To determine the current incidence of NPC in Japan we examined NPC case in the Chubu area from 1986 to 1995. The leaders and reporting representatives of all otorhinolaryngological groups in the area were asked for their support of this epidemiological research. A total of 607 cases (445 male and 162 female NPC patients) were analyzed epidemiologically, histologically, serologically and clinically in this study. The incidence of NPC gradually increased with age. The mean age of the patients was 54.1 years. The age-standardized annual incidence in the Chubu region was 0.28 per 10(5) persons per year. The incidence in prefectures bordering Japan Sea (0.36) was significantly higher than that of prefectures facing the Pacific Ocean (0.21, P<0.05). On the basis of World Health Organization (WHO) histological criteria, 12%) of the cases were classified as WHO I, 54% as WHO II and 34% as WHO III. As for tumor origin, in 58% of the cases it originated posterosuperiorly, in 32% laterally and in 1% inferiorly. Tumor staging showed 4% to belong to stage I, 9% to stage II, 15% to stage III and 72% to stage IV. The positive rates of serum titers of the antibodies to Epstein Barr virus

Association of Epstein-Barr virus infection with p53 protein accumulation but not bcl-2 protein in nasopharyngeal carcinoma

AIMS

The aim of this study was to investigate the association of Epstein-Barr virus (EBV) infection with status of p53 protein expression in nasopharyngeal carcinoma (NPC). The expression of EBV gene and gene product, p53 protein and bcl-2 protein in NPC was histopathologically studied.

METHODS AND RESULTS

In-situ hybridization using oligonucleotide probe to EBV-encoded small RNAs (EBERs) and immunohistochemistry using monoclonal antibodies against EBV latent membrane protein 1 (LMP1), p53 protein and bcl-2 proteins were performed in 56 primary NPCs. EBERs were detected in 46 (82%) cases and LMP1 in 17 (30%) cases. While 30 of 32 (94%) cases in differentiated nonkeratinizing carcinoma (NKC, WHO type 2) and 16 of 17 (94%) cases in undifferentiated carcinoma (UC, WHO type 3) showed EBERs expression, neither five cases of keratinizing squamous cell carcinoma (KSCC, WHO type 1) nor two cases of adenocarcinoma showed EBERs. bcl-2 protein was detected in 50 (89%) cases, but its expression did not depend on expression of LMP1. p53 protein was detected in 31 (55%) cases, and there was a correlation between expression of EBERs and p53 protein (P < 0.05) but not between LMP1 and p53 protein.

CONCLUSION

In this study, close association of NKC and UC but not KSCC with the latent infection with EBV was demonstrated. The induction of bcl-2 protein by LMP1, as shown in vitro, was not demonstrated. The association between overexpression of p53 protein and the presence of EBV suggests that some EBV-encoded protein, which may be different from LMP1, may play a role for nuclear accumulation of p53 protein.

Epstein-Barr virus expression within keratinizing nasopharyngeal carcinoma

Three stages of maturation can be seen in keratinizing nasopharyngeal carcinomas. These stages are similar morphologically to basal cells, intermediate and superficial squamous cells seen in normal squamous epithelium. Taking advantage of such a diverse tumour cell population, 10 keratinizing nasopharyngeal carcinoma (NPC) were examined by in situ hybridization for the presence of latent Epstein-Barr Virus (EBV) using EBV encoded RNAs (EBERs) and by immunohistology for the presence of EBV early antigen-diffuse (EA-D) and the 350/220 kd membrane glycoprotein of the EBV. The basal cell-like tumour cells are mainly infected latently with the virus; viral replication was found in isolated intermediate squamous cells, whilst superficial squamous cells are largely depleted of all the viral markers. We used a control series of nonkeratinizing nasopharyngeal carcinomas composed of undifferentiated and poorly differentiated tumour cells and EBV latency was present in these tumours. Viral replication was detected by RT-PCR, in the undifferentiated tumours but viral replication was not seen by immunohistology. The possible relationship between EBV life cycle in these tumours and tumour cell differentiation is discussed in the light of these findings.

Site-specific localization of Epstein-Barr virus in pharyngeal carcinomas

In this study, the correlations of factors with Epstein-Barr virus (EBV)-association were investigated in 50 patients with nasopharyngeal carcinoma (NPC), 61 with oropharyngeal carcinoma (OPC), and 55 with hypopharyngeal carcinoma (HPC) in Okinawa and Osaka prefectures in Japan. The incidence of pharyngeal carcinoma in Okinawa was previously found to be higher than that in Osaka; the incidence of OPC was approximately 6 times higher and that of HPC was two times higher. The EBV genome was detected in the tumor cells of the present patients; 83% of the Okinawa and 92% of the Osaka NPC patients. The EBV genome was not detected in OPC or HPC. A univariate analysis showed that sex, the location of the tumor, histology, and the degree of lymphocytic infiltration correlated with the EBV-positive rate. A multivariate analysis revealed that only the location of the tumor was independently correlated with the EBV-positive rate. Histology and tumor size were factors affecting the prognosis of the patients with NPC. The NPC of poorly differentiated type frequently showed the EBV genome, and NPC with lymphocytic infiltration showed a more favorable prognosis compared to the other NPC types. These findings suggest that latent genes of EBV expressed in cancer cells might trigger a cytotoxic T cell reaction against the cancer.

Detection of the Epstein-Barr virus genome in cervical neoplasia is closely related to the degree of infiltrating lymphoid cells: a polymerase chain reaction and in situ hybridization approach

To cast light on the significance of Epstein-Barr virus (EBV) infection in cervical tumorigenesis, 44 cervical intraepithelial neoplasia (CIN) types I/II, and 70 CIN III lesions, 60 invasive squamous cell carcinomas (ISCC), and 20 normal cervical samples were investigated by polymerase chain reaction (PCR) and RNA in situ hybridization (RISH) assays. The EBV genome was detected by PCR using primers targeting the IR region in three (6.8%) of the CIN I/II, 15 (21.4%) of the CIN III and 13 (21.7%) of the ISCC lesions, while using an EBER oligonucleotide probe RISH revealed positive signals in infiltrating lymphocytes located in the cervical stroma, but not in dysplastic or tumor cells. There was a significant correlation between the presence of EBV DNA and the degree of lymphoid cell infiltration (P = 0.0223). In contrast, none of the normal cervical samples that were without inflammation demonstrated any EBV infection. Thus, the results indicated that a positive result for EBV on PCR may be simply dependent on the amount of lymphocytes in cervical stroma, suggesting that this virus does not play a major role in the etiology of cervical neoplasia.

Latent infection with Epstein-Barr virus in odontogenic disorders: comparison among ameloblastoma, dentigerous cyst and odontogenic keratocyst

In order to investigate the relationship between Epstein-Barr virus (EBV) latent infection and histogenesis of odontogenic disorders, in situ hybridization for EBV-encoded small RNA (EBER) was applied to the paraffin sections of ameloblastoma, dentigerous cyst, and odontogenic keratocyst. Eight cases (15%) of 53 ameloblastomas showed scattered signals for EBER in the parenchymal cells, whereas no reaction of EBER transcript was observed in the non-neoplastic cystic lesions. In the ameloblastoma, the follicular and plexiform types revealed the signals in the nuclei, but cystic, acanthomatous, granular, and basal cell types exhibited no reaction with EBER. The distribution of the signals without monoclonarity indicated that ameloblastoma cells may exclude EBV genomes or inactivate EBER-encoded genes. The results suggested that EBV participates as one of the transforming factors in the occurrence of ameloblastoma.

Treatment of posttransplant lymphoproliferative disease in the central nervous system of a lung transplant recipient using allogeneic leukocytes

Posttransplant Epstein-Barr virus-related lymphoproliferative disease (PT-LPD) is a common and often fatal complication following solid organ and hematopoietic stem cell transplantation. PT-LPD following solid organ transplantation generally occurs in B cells of recipient origin in contrast to PT-LPD in marrow transplant recipients, which is exclusively of donor origin. The efficacy of adoptive immunotherapy using donor leukocytes to treat PT-LPD in bone marrow transplant recipients has recently been reported. Because PT-LPD in solid organ transplant recipients is generally of recipient origin, the potential application of adoptive immunotherapy of PT-LPD in solid organ recipients obligates the use of either autologous or allogeneic HLA identical leukocytes, with the attendant risk of organ rejection if cells mismatched with the transplanted organ are used. Nonirradiated allogeneic mononuclear cells from an Epstein-Barr virus (EBV)-seropositive, HLA-identical normal sibling were used to treat a monoclonal EBV lymphoma of recipient origin in the central nervous system of a child who had undergone an HLA-mismatched cadaveric lung transplant. The patient received three separate mononuclear cell infusions over a 9-month period, each containing 1 x 10(6) CD3+ mononuclear cells per kilogram. Complete clinical, radiological, and pathological remission was achieved with this treatment regimen. The response correlated with in vivo reconstitution of normal EBV-specific cytotoxic activity and cytotoxic T lymphocyte precursor frequency. Use of allogeneic HLA-compatible mononuclear cells may thus offer an additional mode of therapy for EBV-related lymphoproliferative disease in selected solid organ transplant recipients refractory to conventional therapies.

Detection of Epstein-Barr virus in nasopharyngeal carcinoma by in situ hybridization and polymerase chain reaction

The association of Epstein-Barr virus (EBV) with nasopharyngeal carcinoma (NPC) has been shown by various methods. The purpose of this study is to identify the most useful method to detect EBV in NPC. Both polymerase chain reaction (PCR) for EBV-DNA and in situ hybridization for EBV-encoded small RNAs (EBERs) were examined in formalin-fixed, paraffin-embedded NPC specimens. In situ hybridization was performed in 56 cases, and PCR for EBV-DNA was performed in 42 cases. EBV-DNA was detected in 0 of 3 keratinizing squamous cell carcinomas (KSCC), 22 of 24 nonkeratinizing carcinomas (NKC), all 13 undifferentiated carcinomas (UNPC), and 0 of 2 adenocarcinomas (AC). EBERs were detected in 0 of 5 KSCC, 30 of 32 NKC, 16 of 17 UNPC, and 0 of 2 AC. Among them, EBERs was detected in 35 of 42 cases in which PCR was also performed, 0 of 3 KSCC, 22 of 24 NKC, all 13 UNPC, and 0 of 2 AC, respectively. Both results were consistent in 40 of 42 cases. We conclude that both PCR and in situ hybridization are useful to detect EBV in NPC. In situ hybridization has a particular advantage because it can demonstrate the localization of EBV in neoplastic cells. In addition, close association of NKC and UNPC but not KSCC and AC with EBV is suggested.

Lymphoepithelial carcinoma of the larynx and hypopharynx: study of eight cases with relationship to Epstein-Barr virus and p53 gene alterations, and review of the literature

Eight cases of lymphoepithelial carcinoma (LEC) of the larynx and hypopharynx were evaluated for clinicopathologic features, and the presence of the Epstein-Barr virus (EBV) and p53 alterations. The seven men and one woman, all of non-Asian descent, averaged 64 years of age. Eighty-eight percent had histologically confirmed cervical lymph node metastasis at diagnosis. None had systemic disease. Seven of eight patients available for follow-up (mean, 17.7 months) were alive and free of disease, although one did develop recurrent tumor in the neck. Four tumors were composed, histologically, of pure LEC. Four others had foci of both LEC and conventional squamous cell carcinoma. All eight tumors exhibited alterations in p53 expression, but none was positive for EBV. Combining these 8 cases with the 15 previously published cases in the English literature indicate that LEC in this site is a rare, rather aggressive tumor, primarily of older adults (mean, 62 years) with a propensity for early cervical lymph node metastasis and eventual distant dissemination and death from disease in about one third of patients. Although p53 alterations are common and of no apparent prognostic significance, LEC at this site seems to have little, if any, relationship to the EBV in patients of non-Asian origin.

Expression of EBER1 in primary and metastatic nasopharyngeal carcinoma tissues using in situ hybridization. A correlation with WHO histologic subtypes

BACKGROUND

The association of Epstein-Barr virus (EBV) with nasopharyngeal carcinoma (NPC) is well documented. Previous studies reported abundant expression of EBER1 in primary NPC and tumors metastatic to lymph nodes. However, a large series of case studies correlating World Health Organization (WHO) histologic subtypes with EBER1 is needed.

METHODS

The authors applied the EBER1 in situ hybridization to investigate the expression of EBER1 in 140 primary NPCs, 11 metastatic tumors to lymph nodes, 6 metastatic tumors to bone marrow, and 2 metastatic tumors to the liver. All 19 metastatic tumors had paired specimens from their primary NPCs for comparison. The in situ hybridization method was performed on paraffin embedded tissues by using polymerase chain reaction-derived, digoxigenin-labelled EBER1 DNA probes.

RESULTS

The EBER1 signal was identified in nuclei of malignant epithelial cells in 135 of 140 (96.4%) primary NPCs, including 4 of 5 (80%) WHO-I histologic subtypes, 71 of 73 (97.3%) WHO-II histologic subtypes, and 60 of 62 (96.8%) WHO-III histologic subtypes (P > 0.05). However, the positive hybridization signal in WHO-I NPC was less in proportion to malignant cells, usually limited to basal cells, than in other histologic types of NPC. In 10 of 11 specimens with metastases to the lymph nodes, hybridization was always limited to the malignant cells and not associated with lymphocytes. All 10 paired primary NPCs also demonstrated positive EBER1 hybridization. Only one paired specimen showed negative EBER1 in primary NPC and a metastases to a lymph node. Eight distant metastases, all EBER1-positive in their primary NPC, also demonstrated positive EBER1 hybridization signals in the malignant cells. The proportion of EBER1 positivity in metastatic NPC is higher than that in primary lesions as observed in paired specimens from the same patient.

CONCLUSIONS

Because of abundant expression of EBER1 in primary NPC as well as in metastatic malignant cells, it is recommended that EBER1 in situ hybridization be performed on routinely processed specimens whenever NPC is suspected.

Adrenal gland leiomyoma in a child with acquired immunodeficiency syndrome

An adrenal gland leiomyoma was incidentally found at autopsy in a 2-year-old boy with acquired immunodeficiency syndrome (AIDS). Smooth muscle neoplasms have been described in pediatric AIDS and affect mainly the tracheobronchopulmonary, gastrointestinal, and hepatobiliary systems. An association between Epstein-Barr virus (EBV) and smooth muscle tumors in patients with AIDS has been described. This case is the first leiomyoma to be reported in the adrenal gland of a child with AIDS. EBV genome was demonstrated in the tumor by polymerase chain reaction.

Role of Epstein-Barr virus in fine-needle aspirates of metastatic neck nodes in the diagnosis of nasopharyngeal carcinoma

BACKGROUND

The patient with nasopharyngeal carcinoma (NPC) frequently is initially seen with regional node dissemination. Preliminary investigations suggest that the presence of Epstein-Barr virus (EBV) genomes in neck metastases from an occult primary may be diagnostic and predictive of NPC. The goal of this study was to test this proposition.

METHODS

The polymerase chain reaction (PCR) was used to detect the presence of EBV DNA in fine-needle aspirate (FNA) samples obtained from malignant neck nodes. Control samples were obtained from other locations in the head and neck.

PATIENTS

The patients in this study were evaluated at the Toronto Princess Margaret Hospital, a province-wide tertiary-care cancer treatment center. Of the 23 patients evaluated with malignant neck masses, 6 had NPC, 5 patients had metastatic squamous cell carcinoma of an unknown primary, and 12 patients served as controls with other known head and neck carcinomas. One of the patients initially diagnosed as an unknown primary later demonstrated NPC. FNA specimens were also obtained from 24 normal parotid, submandibular, or thyroid glands for comparison.

RESULTS

In the samples with sufficient DNA for analysis, EBV was detected in 5 of 5 neck nodes from patients with known NPC. EBV was also detected in the neck node of a patient who went on to develop NPC and in a cervical node from 1 of 2 patients in whom the primary tumor remained unknown. None of the evaluable control neck nodes of FNA controls from other sites demonstrated EBV.

CONCLUSIONS

These results demonstrate the utility of NPC-diagnostic EBV gene amplification in FNA samples of neck metastases and suggest that the presence of the EBV genome in FNA samples of neck nodes is predictive of the presence of NPC.

Determination of nonendemic nasopharyngeal carcinoma by in situ hybridization for Epstein-Barr virus EBER1 RNA: sensitivity and specificity in cervical node metastases

After time-consuming and costly investigations, patients with neck metastases from an occult primary often receive unnecessarily large radiation volumes to treat a possible origin in the nasopharynx. In this study a colorimetric antisense Epstein-Barr early ribonucleoprotein 1 (EBER1) oligonucleotide probe specific for Epstein-Barr virus RNA was hybridized in situ to metastatic tissue obtained from 18 nasopharyngeal, 54 oral and pharyngeal, and 12 occult carcinomas derived from an unselected population. All 16 nonkeratinizing nasopharyngeal carcinomas (NPCs) were positive for EBER1. Both cases of keratinizing NPC and all 54 other metastases were negative. A single positive case of occult carcinoma indicated its origin from NPC. In retrospect, 7 patients with occult carcinoma had received unnecessary treatment with irradiation to the nasopharynx. Nasopharyngeal carcinoma appears to be a less common origin of occult carcinoma than previously considered. In the proper clinicopathologic context EBER1 in situ hybridization (EBER1-ISH) allows exclusion of NPC with a high degree of accuracy. Thus unnecessarily large radiation volumes and their adverse sequelae may be reduced in the treatment of occult carcinoma. Conversely, a positive result of ISH allows exclusion of further extensive diagnostic procedures.

Tonsil lymphoma presenting as tonsillitis after bone marrow transplantation

Bone marrow transplantation for the treatment of leukemia is increasingly successful in rendering patients disease free. However, it has become evident that the associated severe immunosuppression predisposes this population to an increased risk for other neoplastic disorders. We report on six patients in whom non-Hodgkin's lymphoma of the tonsillar region developed within 5 months after T-cell-depleted bone marrow transplantation for the treatment of leukemia at Memorial Sloan-Kettering Cancer Center from October 1990 to October 1992. These patients initially had what appeared to be infectious exudative pharyngitis/tonsillitis; however, they did not improve with medical therapy. Because of the persistence of pharyngitis/tonsillitis in association with cervical lymphadenopathy and odynophagia, the patients underwent definitive biopsy in the form of tonsillectomy, cervical lymph node biopsy, or both. Histopathologic review revealed non-Hodgkin's lymphoma. An association with Epstein-Barr virus has been noted in five of these patients. This article is aimed at alerting the clinician to consider the diagnosis of lymphoma in a patient with persistent pharyngitis/tonsillitis despite adequate medical therapy after bone marrow transplantation.

Detection of Epstein-Barr virus and human papillomavirus in nasopharyngeal carcinoma by the polymerase chain reaction technique

We used the PCR technique to detect the Epstein-Barr virus (EBV) and human papillomavirus (HPV) DNA in paraffin-embedded tissues from Greek patients with nasopharyngeal carcinoma (NPC). The oligonucleotide primers used for the detection of EBV amplify a 375-bp long sequence from the EcoRI B fragment of the viral genome, whereas for HPV the primers amplify a 151-bp long sequence of the viral genome. The PCR products were analysed by agarose gel electrophoresis and visualised by UV illumination after staining with ethidium bromide. Sixty-three specimens were examined. EBV specific sequence was amplified in 20 (32%) and HPV in 12 (19%) out of the 63 samples. There was no co-infection with EBV and HPV. Although there is a high correlation of EBV infection with poorly differentiated NPC in patients from Southern China and South-East Asia, the restricted distribution suggests genetic or environmental cofactors in the development of the neoplasm. Our results confirm this suggestion since there was only a 32% correlation of EBV with NPC in Greece. HPV may also be involved in the carcinogenesis of EBV-negative squamous cell nasopharyngeal carcinomas.

Incidence of latent infection of Epstein-Barr virus in lung cancers--an analysis of EBER1 expression in lung cancers by in situ hybridization

To evaluate the presence of Epstein-Barr virus (EBV) in lung cancers of Japanese patients, 81 lung cancers were examined using a highly sensitive in situ hybridization (ISH) method, employing an antisense oligonucleotide probe for EBV-encoded small nuclear RNA-1 (EBER). EBER1 expression was demonstrated in one poorly differentiated squamous cell carcinoma associated with marked lymphoid stroma (PDSCC-LS), two well differentiated adenocarcinomas, and two moderately differentiated squamous cell carcinomas, but was not detectable in other lung cancers, including small cell carcinomas. Unlike lymphoepithelioma-like undifferentiated carcinoma (LELC) of the lung, the PDSCC-LS consisted of poorly differentiated cells with distinct cell borders and nuclei with a coarse chromatin pattern and some prominent nucleoli. Most of the cancer cells expressed intense EBER1 signals. Although small to moderate numbers of cells positive for EBER1 were present in two adenocarcinomas and two squamous cell carcinomas, EBER1 signals varied in intensity and number in these four cases. Although polymerase chain reaction (PCR) and Southern blot hybridization with a 32P-labelled probe internal to the primers were conducted to detect the EBV genome in 24 lung cancers, including five EBER1-positive cases, the genome was found to be positive in the five cases with EBER1-positive staining, including the PDSCC-LS, two adenocarcinomas and two squamous cell carcinomas, but not in the other cases. This study indicates that the morphological features of EBV-associated lung cancers are not restricted to the typical LELC type.

A molecular study of EBV DNA and p53 mutations in nasopharyngeal carcinoma of Saudi Arab patients

Tumor biopsies obtained from 25 Saudi Arab patients with nasopharyngeal carcinoma (NPC) were examined for the presence of Epstein-Barr virus (EBV) DNA detected by the polymerase chain reaction (PCR) and for the incidence of p53 mutations screened by a combination of PCR, single strand conformation polymorphism (SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP). DNA sequencing was carried out to confirm the occurrence of p53 mutation. While 92% of the tumor specimens were found to carry EBV DNA, only 1/25 showed the incidence of a homozygous mutation at codon 248 of the p53 gene. The data showed that despite a high association of EBV infection with Saudi NPC, the frequency of p53 mutations was very low. Our results are consistent with the worldwide observation of infrequent p53 mutations in NPC.

Infusions of donor leukocytes to treat Epstein-Barr virus-associated lymphoproliferative disorders after allogeneic bone marrow transplantation

BACKGROUND

Lymphoma associated with Epstein-Barr virus (EBV) is a complication of bone marrow transplantation that responds poorly to standard forms of therapy. The lymphoma is usually of donor origin. We hypothesized that treatment with infusions of donor leukocytes, which contain cytotoxic T cells presensitized to EBV, might be an effective treatment.

METHODS

We studied five patients in whom EBV-associated lymphoproliferative disorders developed after they received a T-cell-depleted allogeneic bone marrow transplant. Biopsy specimens were immunophenotyped, subjected to the polymerase chain reaction to determine the origin of the lymphoma (donor or host) and to detect the presence of EBV, and analyzed by Southern blotting for the presence of the clonal EBV genome and immunoglobulin-gene rearrangement. Patients were treated with infusions of unirradiated donor leukocytes at doses calculated to provide approximately 1.0 x 10(6) CD3+ T cells per kilogram of body weight.

RESULTS

Histopathological examination of biopsy specimens from all five patients demonstrated monomorphic, malignant lymphomas of B-cell origin. Each of the four specimens that could be evaluated was of donor-cell origin. Evidence of clonality was found in two of the three samples adequate for study. EBV DNA was detected by the polymerase chain reaction in all five samples. In all five patients there were complete pathological or clinical responses. The responses were first documented histologically within 8 to 21 days after infusion. Clinical remissions were achieved within 14 to 30 days after the infusions and were sustained without further therapy in the three surviving patients for 10, 16, and 16 months.

CONCLUSIONS

In a small number of patients, infusions of unirradiated donor leukocytes were an effective treatment for EBV-associated lymphoproliferative disease that arose after allogeneic bone marrow transplantation.

Absence of a reservoir of Epstein-Barr virus (EBV) in normal tongue epithelium

We examined human tongue epithelium and serum samples at autopsy for evidence of latent Epstein-Barr virus (EBV) infection. Although clinical serology revealed anti-EBV antibodies in most sera indicating past EBV infection, we found no Epstein-Barr nuclear antigen (EBNA)-coding sequences in tongue tissue by polymerase chain reaction (PCR), or Epstein-Barr-encoded RNA (EBER1) by in situ hybridization. Tongue epithelium does not appear to be a natural reservoir for latent EBV in immunocompetent hosts.

The detection of the c-myc and ras oncogenes in nasopharyngeal carcinoma by immunohistochemistry

Forty-one paraffin embedded specimens of primary nasopharyngeal carcinoma (NPC) were examined to investigate the expression of c-myc and ras oncogenes. Sections were stained with the monoclonal antibodies myc 1-9E10 or ras Y13-259 and binding was detected using the ABC method. The intensity of staining for each tumour was assessed as nil, moderate or intense. The results indicated that 9 (22%) had intense staining for the c-myc oncogene, 28 (68%) had moderate staining and only 4 (10%) showed no staining. For the ras oncogene, 8 (19%) had intense staining, 22 (54%) moderate staining and 11 (27%) showed no staining. The patient's clinical data indicated no correlation between the expression of either c-myc or ras p21 and age, sex, smoking, tumour stage, antibody titre to EBV, or family history. No correlation was found between ras p21 expression and survival; however, overexpression of the c-myc oncogene correlated with a poor prognosis (p < 0.05). This study is consistent with investigations demonstrating that c-myc expression correlates with poor survival in head and neck tumours.

Absence of Epstein-Barr virus in carcinoma of the cervix

BACKGROUND

Cervical epithelium is known to contain receptors for Epstein-Barr virus (EBV) and is a recognized site of viral shedding. Recent cases of nasopharyngeal carcinoma have been associated with cervical carcinoma, leading to speculation of a possible etiologic link between EBV and cervical carcinoma.

METHODS

This study investigates the presence of EBV in 24 cases of invasive cervical carcinoma (9 adenocarcinomas and 15 squamous cell carcinomas) and 10 cases of cervical intraepithelial neoplasia (4 adenocarcinomas in situ and 6 squamous: 3 CIN II, 3 CIN III), using in situ hybridization.

RESULTS

In one case, EBV was demonstrated in infiltrating lymphocytes adjacent to tumor epithelium, but in no cases did the malignant epithelium show the presence of EBV.

CONCLUSIONS

These results suggest that EBV does not play a role in the etiology of cervical carcinoma, although further studies are needed.

Nasopharyngeal carcinoma: histopathological types and association with Epstein-Barr Virus

The polymerase chain reaction was used to examine paraffin-embedded tissues of 37 nasopharyngeal carcinomas (NPC) for Epstein-Barr virus (EBV) genomic sequences. EBV DNA was found in 2/14 keratinising squamous cell (WHO 1) carcinomas and in all of 23 non-keratinising and undifferentiated (WHO 2 and 3) NPC. The study confirms the infrequent association of keratinising NPC and EBV, in contrast with the 100% association of the less differentiated NPCs and the virus. The results may indicate a different carcinogenesis for the WHO 1 NPC subtype.

Detection of Epstein-Barr virus in a case of undifferentiated nasopharyngeal carcinoma by in situ hybridization with digoxigenin-labelled PCR-generated probes

A case of nasopharyngeal carcinoma is presented. Epstein-Barr viral genome was identified in the neoplastic cells by in situ hybridization with digoxigenin-labelled polymerase chain reaction-generated probes. We report the development of this technique in paraffin-embedded sections and propose that such identification may prove valuable for the diagnosis of this tumour in routine material.