1/12. Epstein-Barr virus-associated high-grade anaplastic plasmacytoma in a renal transplant patient.Allograft transplant patients have an increased risk of developing polyclonal or monoclonal lymphoproliferative disorders, but high-grade anaplastic plasmacytomas are extremely rare in these patients. We present a renal transplant patient who developed multiple extramedullary high-grade anaplastic plasmacytomas in the oral cavity, the left maxillary antrum, the scalp, the thigh and the upper abdominal wall with no evidence of diffuse bone marrow infiltration. Epstein-Barr virus (EBV) mRNA transcripts were detected within the myeloma cells by in situ hybridization using EBER1-2 probes. Following discontinuation of immunosuppression applied, the patient was treated with a cyclophosphamide-prednisone regimen followed by local irradiation, and a complete remission was achieved within four weeks. We concluded that EBV-associated high-grade anaplastic plasmacytomas constitute one more type of post-transplant lymphoproliferative disorder, and that despite their characterization as highly malignant neoplasms, their clinical behavior is not always aggressive.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/12. Supernumerary ring chromosomes derived from the long arm of chromosome 12 as the primary cytogenetic anomaly in a rare soft tissue chondroma.Supernumerary ring chromosomes varying with respect to both size and number were found as the primary cytogenetic anomaly in a rare benign soft tissue chondroma resected from the floor of the mouth of a 3-year-old girl. Reverse fluorescence in situ hybridization paint probes prepared by polymerase chain reaction from microdissected rings produced fluorescent signal over two large but discontinuous parts of the chromosome 12 long arm, subdivided into four regions. This case expands the spectrum of mesenchymal neoplasms in which ring chromosomes have been described as the primary genetic anomaly. A review of the literature reporting similar findings in other soft tissue tumors further supports the possibility that low-level amplification of chromosome 12 long-arm regions may contribute to abnormal cellular proliferation in a variety of mesenchymal tumors. Genes implicated in the control of the cell cycle such as sarcoma amplified sequence (SAS), the human homolog of the murine double-minute type 2 gene (MDM-2), proto-oncogenes CHOP/GADD153, GLI, A2MR, cyclin-dependent kinase (CDK4), and the high mobility group (HMGIC) gene implicated in mesenchymal tumorigenesis are all located on the long arm of chromosome 12. Chromosomal abnormalities involving the 12q13-q15 region are associated with a wide range of benign soft tissue tumors and sarcomas.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/12. Warty carcinoma of the oral mucosa in an hiv patient.The authors present the case of a 36-year-old hiv male patient with a 1-cm diameter papillary exophytic lesion of the right cheek. Microscopic examination showed a papillary epithelial neoplasm with invasion of the stroma in the peripheral part. Cellular and nuclear atypia were present in the superficial and in the deep layers of the neoplasm. An in situ hybridization for human papillomavirus (HPV) 6, 11, 16, 18, 31, 35 and 51 was performed. A focal positivity only for HPV 16 and 18 was present in koilocytotic cells of the most peripheral portion of the lesion. The microscopic definitive diagnosis was warty carcinoma of the cheek. No recurrence was observed at a 3-year follow-up.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/12. Plasmablastic lymphoma: an hiv-associated entity with primary oral manifestations.Plasmablastic lymphoma is a relatively new entity that is considered to be a diffuse large B-cell lymphoma with an unique immunophenotype and a predilection for the oral cavity. We present a 50 year-old hiv-positive, bisexual, white male with a CD4 count 300/mm(3) and a viral hiv-rna polymerase chain reaction (PCR) load of 237 copies/ml, who developed a painful, purple-red mass in the edentulous area of the maxillary right first molar. Erythematous gingival enlargements of the interdental papillae were seen in three of the dental quadrants. In addition, the patient was being managed with antiretroviral therapy and liposomal doxorubicin for recurrent cutaneous Kaposi's sarcoma (KS). Although oral KS was suspected, the gingival lesions were biopsied because they were refractory to chemotherapy and a lymphoma could not be excluded. Histopathologic examination revealed a lymphoid malignant neoplasm, consistent with a plasmablastic lymphoma. Immunoreactivity with vs38c, CD79a, kappa light chain, and IgG was readily identified in tumor cells; while only focal cells expressed CD20 and LCA (CD45RB). CD56, CD3, lambda light chain, and EMA were non-reactive. EBV was detected in the tumor by Southern hybridization, PCR amplification, in situ hybridization for EBER-1 dna, and immunohistochemistry for latent membrane protein-1. The same tumor was negative for HHV-8 by PCR. Recognition of plasmablastic lymphoma is important, because it represents an hiv-associated malignancy that predominantly involves the oral cavity, may mimic KS and has a poor prognosis.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
5/12. Upregulation of cystatin m during the progression of oropharyngeal squamous cell carcinoma from primary tumor to metastasis.To identify metastasis-associated molecules in oropharyngeal squamous cell carcinomas (OSCC), we recently compared mRNA expression profiles of cell lines derived from primary and metastatic lesions of OSCC using microarray technology. cystatin m, an endogenous cathepsin b inhibitor, was expressed 40-fold higher in the metastatic versus the primary tumor cell line. To show that different cystatin expression levels affect the cell lines' sensitivities to TNF-induced apoptosis by differentially regulating cathepsin b activity. The 686Tu and 686Ln cell lines were established from a 49-year-old male patient with an OSCC involving the posterior tongue and oro-pharynx (tumor stage T(3)N(3B)). RT-PCR, Western blots, immunohistochemistry, and in situ hybridization all confirmed increased cystatin m expression in 686Ln compared to 686Tu cells, and in the parent archival tumors. TNF-alpha induced apoptosis was easily detected in 686Tu, but only marginally in 686Ln cells. Thus, we propose that elevated cystatin m expression aids metastasis by blocking intrinsic cathepsin b activity and rescuing tumor cells from TNF-induced apoptosis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/12. Human papillomavirus type 16 dna in oral white sponge nevus.White sponge nevus (WSN) is a benign hereditary lesion of the mucous membranes. dna extracted from a biopsy specimen of oral WSN was assayed for the presence of dna sequences homologous to human papillomavirus (HPV) types 1, 2, 4, 6, 11, 13, 16, and 18 by Southern blot hybridization. Only HPV-16 homologous dna sequences were detected at a copy number of approximately 200 to 250 genome copies per diploid cell. The viral dna sequences did not appear to be integrated into the host cell chromosome. The finding of HPV-16 in an inherited lesion such as WSN indicates that caution must be exercised in ascribing a causal association in relation to the demonstration of HPV in other mucosal disorders.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/12. Cytogenetic characteristics of oral squamous cell carcinomas in fanconi anemia.fanconi anemia (FA) is an autosomal recessive syndrome with a marked predisposition to malignancies, in particular acute myeloid leukemia and squamous cell carcinoma of the oral cavity. We examined oral squamous cell carcinoma tissue from two FA patients (FA-A and FA-C) by comparative genomic hybridization. Both tumors, which were negative for human papilloma as well as Epstein-Barr viral sequences, showed multiple alterations with a high proportion of whole-arm chromosomal gains and losses. This combination of features as well as the sites involved in chromosomal breakage are very similar to what is typically observed in non-FA oral tumors. These results suggest that the process leading to early occurrence of oral cancer in FA patients follows a similar pathway as in non-FA cancer patients, which would support a caretaker function for FA genes in the protection against oral carcinogenesis. Since FA patients are uniquely hypersensitive to dna cross-linking agents, while oral cancer in the general population is thought to be environmentally induced, these results also suggest that environmental dna cross-linkers may be causally involved in oral carcinogenesis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/12. composite lymphoma: angiocentric T-cell lymphoma (CD8 cytotoxic/suppressor T-cell) and diffuse large B-cell lymphoma associated with EBV, and presenting clinically as a midfacial necrotizing lesion.A composite lymphoma is defined as the simultaneous occurrence of two histologically different types of lymphomas situated in one anatomical location. Reports of composite B- and T-cell lymphomas, especially in the head and neck region, are rare. We describe a 76-year-old Taiwanese aboriginal female patient clinically presenting with a midfacial necrotizing lesion (MNL). Microscopic examination of the incisional biopsy specimen revealed extensive surface necrosis with infiltrates of inflammatory cells. Beneath the necrotic surface, there appeared to be two distinct populations of pleomorphic lymphoid cells exhibiting the characteristic features of the angiocentric distribution of the tumor cells and evidence of angiodestruction. Immunohistochemical staining revealed that these atypical lymphoid cells were positive for LCA, CD45, CD5, CD20, CD3 epsilon, CD8, bcl-2 and bcl-6 and negative for CD56, CD4, CD68, keratin, S-100, kappa and lambda. Furthermore, these atypical lymphoid cells also expressed EBV-encoded nuclear RNAs (EBERs) following in situ hybridization. Therefore, this was a case of composite lymphoma: angiocentric T-cell lymphoma (ATCL) (CD8 cytotoxic/suppressor T-cell) and diffuse large B-cell lymphoma (DLBL) associated with the Epstein-Barr virus (EBV) and presenting clinically as MNL.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/12. Unusual oral presentation of non-Hodgkin's lymphoma in association with hiv infection.In 4.4% of human immunodeficiency virus-associated non-Hodgkin's lymphoma the presenting lesion is seen in the mouth. Often the lesion may clinically resemble a less sinister process, and a definitive diagnosis of lymphoma may be delayed. We describe three unusual cases of non-Hodgkin's lymphoma, appearing intraorally in association with other oral lesions, in hiv-positive homosexual men. The three patients reported here were all diagnosed as having diffuse, large-cell malignant non-Hodgkin's lymphoma. We performed Epstein-Barr virus dna in-situ hybridization on our cases and Epstein-Barr virus dna sequences were not seen. We review the pertinent literature and stress the importance of including non-Hodgkin's lymphoma in the differential diagnosis of oral lesions in patients at risk of hiv infection.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/12. Infantile condylomata of the oral cavity.A child had condylomata acuminata localized to the oral cavity. Main points of interest were this exclusive localization, the extremely high number of papillary lesions, not reported in the literature until now, and the excellent response to interferon and local applications of podophyllin. Histologic, ultrastructural, and in situ molecular hybridization techniques were performed to make a correct diagnosis. Transmission of the etiologic agent and therapeutic approaches are discussed.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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