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PubMed1978

Malignant lymphomas and undifferentiated small cell carcinoma of the thyroid: a clinicopathological review in the light of the Kiel classification for malignant lymphomas.

The paper reports a re-evaluation--based on the Kiel classification for non-Hodgkin lymphomas--of a group of cases initially diagnosed as undifferentiated small cell carcinomas or primary lymphomas of the thyroid. Twelve such cases were found among the 155 cases of primary malignant tumours of the thyroid recorded at the Institut Jules Bordet between 1955 and 1975. The review of the clinical charts and the histology showed that all the cases were in fact malignant lymphomas fitting easily into one of the groups described in the Kiel classification. These findings support the growing opinion that undifferentiated small cell carcinoma of the thyroid does not exist as a distinctive clinicopathological entity. Furthermore, the Kiel classification proved to be an excellent prognostic indicator, since all the cases classified as highly malignant were indeed fatal, whereas the surviving cases--three of which had shown tumoral extension beyond the thyroid capsule--fell into the group of low malignancy. Lastly, this study acknowledges the frequently observed association of malignant lymphoma of the thyroid with stigmata of Hashimoto's disease, and thus supports the concept that the continuous antigenic stimulation observed in the latter could trigger the development of a malignant lymphoma.

Aged↗

PubMed2006

Biopsy vs. superficial scraping: detection of human papillomavirus 6, 11, 16, and 18 in potentially malignant and malignant oral lesions.

BACKGROUND: Several epidemiologic studies have shown a broad variation in the prevalence of human papillomavirus (HPV) in oral precancerous tissues and oral carcinomas. METHODS: Biopsies and superficial scrapes of lesions, clinically suspected of HPV infection, were taken from patients with potentially malignant and malignant oral lesions, and subject to HPV DNA detection by PCR-Southern blot analysis. RESULTS: From 22 patients with potentially malignant and malignant lesions analyzed, 41% of the biopsies were HPV DNA positive, whereas 95-100% of the superficial scrapes were positive (McNemar, P < 0.0001). Clinical presumption of HPV infection detected 67% (P < 0.0001) of the HPV DNA positive cases compared with 48% (P < 0.0001) determined by cytology and histopathology. The prevalence of HPV 6, 11, 16 and 18 in the oral mucosa was studied in 59 individuals. While 9% of normal controls were HPV DNA positive, 100% of the patients with potentially malignant and malignant lesions were HPV DNA positive, and the prevailing genotype was HPV 16 followed by HPV 18. CONCLUSIONS: The higher HPV DNA detection rate in superficial oral scrapes than in biopsies suggests that accurate epidemiological information on oral HPV infection/oral carcinogenesis depends not only on the DNA detection technique, but also on the tissue/cell sampling procedure.

Adult↗

PubMed2004

Malignant peripheral nerve sheath tumour-like primary cutaneous malignant melanoma.

Malignant melanoma is known for its protean cytomorphological features, architectural patterns, and stromal changes, in addition to its ability to mimic various benign and malignant non-melanocytic tumours. Anecdotal cases of metastatic malignant melanoma simulating soft tissue sarcomas have been reported. Interestingly, this mimicry is more often seen in recurrent lesions and metastatic deposits. This report describes a case of a primary spindle cell cutaneous malignant melanoma with a prominent neural-like fascicular pattern and nuclear palisading, simulating a conventional malignant peripheral nerve sheath tumour (MPNST). Clinical, microscopic, and immunohistochemical features of the different entities included in the differential diagnosis of cutaneous spindle cell malignant tumours, such as MPNST, atypical fibroxanthoma, and spindle cell squamous cell carcinoma are discussed. Of note, the presence of an atypical epidermal or junctional component, cell pigmentation, and cell nesting, in addition to diffuse and strong reactivity for S-100 protein and other melanocytic markers, are helpful in the diagnosis of these troublesome lesions.

Biomarkers, Tumor↗

PubMed1999

Locally recurrent malignant fibrous histiocytoma: a rare and aggressive genitourinary malignancy.

OBJECTIVE: In this study, 22 cases of locally recurrent urological malignant fibrous histiocytoma were reviewed considering therapeutic options, follow-up and prognosis. PATIENTS AND METHODS: In the available literature on this topic we identified 19 cases of locally recurrent genitourinary malignant fibrous histiocytoma. Three additional cases are discussed, primarily arising from the kidney, the bladder and the paratesticular region. RESULTS: The prognosis of locally recurrent urological malignant fibrous histiocytoma was found to be extraordinarily poor. Only 2 of 22 patients have survived for longer than 3.5 years. One of them reported herein is still alive 10 years after extensive lymphatic spread accompanying the first local recurrence. In this case, late local recurrence occurred after an 8-year interval free of disease. CONCLUSION: Malignant fibrous histiocytoma is an unusual urological malignancy with a high rate of local recurrence. The latter is frequently accompanied by metastatic disease and unrelenting progression. Despite the poor prognosis early detection of local failure and aggressive salvage therapy might offer the chance of long-term survival in selected cases. Close and life-long follow-up is advisable for patients once treated for recurrent urological malignant fibrous histiocytoma.

Aged↗

PubMed2004

Radiologists' performance for differentiating benign from malignant lung nodules on high-resolution CT using computer-estimated likelihood of malignancy.

OBJECTIVE: The purpose of our study was to evaluate whether a computer-aided diagnosis (CAD) scheme can assist radiologists in distinguishing small benign from malignant lung nodules on high-resolution CT (HRCT). MATERIALS AND METHODS: We developed an automated computerized scheme for determining the likelihood of malignancy of lung nodules on multiple HRCT slices; the likelihood estimate was obtained from various objective features of the nodules using linear discriminant analysis. The data set used in this observer study consisted of 28 primary lung cancers (6-20 mm) and 28 benign nodules. Cancer cases included nodules with pure ground-glass opacity, mixed ground-glass opacity, and solid opacity. Benign nodules were selected by matching their size and pattern to the malignant nodules. Consecutive region-of-interest images for each nodule on HRCT were displayed for interpretation in stacked mode on a cathode ray tube monitor. The images were presented to 16 radiologists-first without and then with the computer output-who were asked to indicate their confidence level regarding the malignancy of a nodule. Performance was evaluated by receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve (Az value) of the CAD scheme alone was 0.831 for distinguishing benign from malignant nodules. The average Az value for radiologists was improved with the aid of the CAD scheme from 0.785 to 0.853 by a statistically significant level (p = 0.016). The radiologists' diagnostic performance with the CAD scheme was more accurate than that of the CAD scheme alone (p < 0.05) and also that of radiologists alone. CONCLUSION: CAD has the potential to improve radiologists' diagnostic accuracy in distinguishing small benign nodules from malignant ones on HRCT.

Diagnosis, Differential↗

PubMedDate not supplied

[Awareness and feelings of elderly patients and their families concerning disease during terminal hospitalization--malignancy versus non-malignancy].

We conducted a questionnaire survey on the awareness and feelings of elderly patients and their families concerning their diseases and prognosis during terminal hospitalization. Sixty-five families of 177 patients who died at our hospital in 1992 answered questions concerning estimation of the prognosis, understanding of the disease, satisfaction regarding explanation of the disease, wish to be informed of the diagnosis, feelings during hospitalization, and whether the family revealed the diagnosis to the patient. Patients with malignancy were not informed of the true diagnosis at this time. As to estimation of the prognosis, patients aged 70 or older who did not expect "cure" of their diseases at first were significantly fewer, and those anticipating "death" just before dying were significantly more frequent than those under age 70. In patients with malignancy, those aged 70 or older foresaw "incurability" at first significantly more frequently than those under age 70. Patients with malignancy knew the diagnosis in significantly fewer cases, believed the false diagnosis significantly more frequently, and showed dissatisfaction with the explanation of the disease significantly more frequently, than those with non-malignancy. Proportions of the family who told the diagnosis to the patient were 11.8% in malignancy and 38.8% in non-malignancy with statistical significance. These data indicate that medical care during terminal hospitalization should be modified principally based on informed consent, if that is the wish of the patient.

Aged↗

PubMed1995

Malignant inverted papilloma of the urinary bladder: the histopathological aspect of malignant potential of inverted papilloma.

To investigate the histopathological characteristics of inverted papillomas of the urinary bladder, including the possibility of malignant transformation, we studied the indicators of cellular proliferation activity in 7 inverted papillomas of the bladder including two cases of malignant inverted papilloma of the bladder. PCNA expression rates in two cases of malignant inverted papilloma were higher than in benign inverted papillomas. Mean numbers of AgNORs per nucleus in malignant inverted papillomas were much more than in benign inverted papillomas. The c-erbB-2 oncoprotein was expressed only in malignant inverted papillomas. These results suggest that PCNA expression rate, mean number of AgNORs per nucleus and c-erB-2 oncoprotein expression may be merited as good indicators to detect the inverted papilloma with more proliferative and aggressive lesions, and with the potential of malignant transformation.

Adult↗

PubMed2006

Malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation (malignant triton tumor).

Malignant peripheral nerve sheath tumors arise from Schwann cells or within existing neurofibromas and have a strong association with type 1 neurofibromatosis. These tumors are histologically diverse and may contain malignant areas of divergent mesenchymal differentiation, the most common of which is skeletal muscle (rhabdomyosarcoma). Malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation is also known as malignant triton tumor. Malignant triton tumor has a worse prognosis than classic malignant peripheral nerve sheath tumor does, and the correct diagnosis requires attention to the clinical history and knowledge of the complexities regarding its differential diagnosis. In this review we discuss the clinical, histopathological, immunohistochemical, and prognostic features of this rare neoplasm.

Biomarkers, Tumor↗

PubMed1999

Differences in levels of soluble E-selectin and VCAM-1 in malignant versus non malignant Mediterranean spotted fever.

In the present study, we investigated the plasma levels of soluble adhesion molecules E-selectin, P-selectin, intercellular adhesion molecule- (ICAM- ) and vascular cell adhesion molecule-1(VCAM-1) in 24 patients with Mediterranean spotted fever (MSF), 6 of whom with a malignant form. Measurements were performed on blood samples collected before treatment (T1), then twice during treatment (T2 and T3). Before treatment, MSF patients taken as a whole presented elevated levels of sICAM-1 and sVCAM-1 and normal levels of sE-selectin and sP-selectin compared to healthy controls. We found that sICAM-1 was elevated both in mild and malignant MSF. sE-selectin and sVCAM-1 were elevated only in patients with the malignant form and allowed to discriminate the two clinical subgroups. Their levels decreased after treatment with sE-selectin reaching control values at T2 whereas sVCAM-1 remained higher over the course of the malignant form. In patients with mild MSF, sP-selectin steadily increased after treatment, whereas it did not present any modification at any of the two sampling times in patients with the malignant form. Raised plasma levels of sE-selectin and sVCAM-1 reflect endothelial activation in malignant rickettsial disease and may be sufficiently early markers to influence the therapeutic decision.

Adult↗

PubMedDate not supplied

Immunohistochemical study of the BCAR1/p130Cas protein in non-malignant and malignant human breast tissue.

BCAR1/p130Cas is a docking protein involved in intracellular signaling pathways and in vitro resistance of estrogen-dependent breast cancer cells to antiestrogens. The BCAR1/p130Cas protein level in primary breast cancer cytosols was found to correlate with rapid recurrence of disease. A high BCAR1/p130Cas level was also associated with a higher likelihood of resistance to first-line tamoxifen treatment in patients with advanced breast cancer. Using antibodies raised against the rat p130Cas protein, we determined by immunohistochemical methods the BCAR1/p130Cas localization in primary breast carcinomas, in tumors of stromal origin, and in non-neoplastic breast tissues. The BCAR1/p130Cas protein was detected in the cytoplasm of non-malignant and neoplastic epithelial cells and in the vascular compartment of all tissue sections analyzed. Immunohistochemistry demonstrated variable intensity of BCAR1/p130Cas staining and variation in the proportion of BCAR1/p130Cas-positive epithelial tumor cells for the different breast carcinomas. Double immunohistochemical staining for BCAR1/p130Cas and estrogen receptor confirmed coexpression in non-malignant luminal epithelial cells and malignant breast tumor cells. The stromal cells in non-malignant tissues and tumor tissues as well as breast tumors of mesodermal origin did not stain for BCAR1/p130Cas. This immunohistochemical study demonstrates a variable expression of BCAR1/p130Cas in malignant and non-malignant breast epithelial cells, which may be of benefit for diagnostic purposes.

Adult↗

PubMedDate not supplied

Expression of p53, cyclin D1 and Ki-67 in pre-malignant and malignant oral lesions: association with clinicopathological parameters.

In this study, a possible association was examined between the immunoexpressions of p53, cyclin D1, Ki-67 and tobacco exposure and the risk of oral cancer (OC) in premalignant and malignant formalin-fixed, paraffin-embedded oral mucosal tissue specimens from patients from Yemen (n=24, all were pre-malignant) and India (n=16, 11 were OCs). Overexpressions of p53, cyclin D1 and Ki-67 were found in 100%, 45.5% and 80% of the OCs, compared to 65.5%, 82.8% and 85.1% of the pre-malignant lesions, respectively. In the pre-malignant lesions, a statistically significant correlation was found between histopathological grading and expressions of cyclin D1 (p = 0.001) and Ki-67 (p = 0.03), and between anatomical site and expression of Ki-67 (p = 0.01). Coexpressions of the three proteins in the cases examined was found to correlate significantly to each other (cyclin D1: p53, r = 0.48, p = 0.002; p53: Ki-67, r = 0.41, p = 0.008) except for cyclin D1: Ki-67. These findings suggest that the expressions of p53, cyclin D1 and Ki-67 might contribute to OC susceptibility in oral mucosal lesions examined from Yemen and India. The importance of the three proteins examined as biomarkers in OC and pre-malignant lesions deserves particular attention because it might offer further understanding of the development of these lesions, particularly in populations heavily exposed to tobacco habits. Abnormalities of both cyclin D1 and Ki-67 might play an important role in the development of oral pre-malignant lesions and warrant further studies. Larger studies are, therefore, necessary in the two countries to examine the role of these biomarkers in OCs and premalignant oral mucosal lesions.

Adult↗

PubMed2006

[Clinical study of oral and maxillofacial malignancies associated with multiple primary malignant neoplasms].

OBJECTIVE: To study the clinical characteristics, diagnosis and treatment strategy of oral and maxillofacial malignancies in multiple primary malignant neoplasms (MPMNs). METHODS: 21 cases of oral and maxillofacial malignancies associated with MPMNs admitted to our hospital between 1985 and 2000 were studied respectively. RESULTS: There were 44 malignant cases in the 21 MPMNs patients. Among the 44 cases, there were 24 cases in alimentary and respiratory tract such as oral, pharynx, esophagus, stomach and lung, and 10 cases in salivary gland, breast and female reproductive system. There were 25 cases malignant neoplasms in oral and maxillofacial region where squamous cell carcinoma was the most common pathologic type, secondly adenoid cystic carcinoma. In oral and maxillofacial region, MPMNs were often found in tongue, parotid and submandibular gland, buccal mucosa and gingival. CONCLUSION: Tongue and salivary gland were the common locations with MPMNs, and they were closely associated with alimentary and respiratory tract. Patients with malignancies of oral and maxillofacial region associated with MPMNs must be submitted to a long-term and careful follow-up. For female patients, breast and female reproductive system should be examined specially. Regular follow-up, early detection, early diagnosis, active and effective treatment can help to improve the survival quality of MPMNs patients.

Aged↗

PubMed1990

[Respiratory malignancies induced by asbestos exposure and evaluation of cases with typical pleural malignant mesothelioma and lung cancer with asbestosis].

Asbestos exposure induces lung fibrosis, i.e. asbestosis, and furthermore, pathological changes of pleura, i.e. asbestos pleurisy of pleural plaque. Generally, asbestosis is induced by massive exposure to asbestos and pleural changes are induced by low dose exposure to asbestos. The most important diseases which are induced by asbestos exposure are malignancies, especially malignant mesothelioma and lung cancer. Two cases, one malignant mesothelioma, the other lung cancer with asbestosis induced by asbestos exposure received almost the same dose of asbestos, as estimated from the period of asbestos exposure and occupational history and the same kind of asbestos (crocidolite) and had a smoking history. We do not know which elements may induce malignancies under asbestos exposure. Recently, some reports described that asbestos mediated the transformation of genes and this action induced malignancies. We should extend our study to the gene problem in cases of malignant mesothelioma and lung cancer induced by asbestos exposure.

Aged↗

PubMed1990

Quantitative cytochemical detection of malignant and potentially malignant cells in the colon.

It was found to be possible to distinguish malignant cells from normal cells by using an oxygen-sensitive tetrazolium salt (neotetrazolium) for the histochemical demonstration of glucose-6-phosphate dehydrogenase activity in cryostat sections of human colon. We have studied 12 cases of established adenocarcinoma of the colon in addition to 4 of ulcerative colitis and 4 of adenomatous polyposis (polyposis coli). In a nitrogen atmosphere the activities of malignant and normal cells were similar. However, after incubation in an atmosphere of pure oxygen, only malignant cells gave a positive reaction after 5 min. Three of the four cases of adenomatous polyposis gave a positive reaction for glucose-6-phosphate dehydrogenase activity in oxygen in a manner similar to that of specimens with severe dysplasia. In general, positive foci were histologically indistinguishable from the neighboring tubuli. However, foci of severely dysplastic epithelium usually showed a positive reaction. All three patients eventually developed clear-cut severe dysplasia. The other patient, who showed a negative reaction in oxygen, was diagnosed after 3 years as not suffering from dysplasia. All cases of ulcerative colitis gave a reaction in oxygen comparable with that of normal cells. Therefore, the areas with a positive reaction are considered to be either in the process of malignant transformation or malignant. An explanation for the oxygen insensitivity of cancer cells appeared to be a decrease in the activity of superoxide dismutase (EC 1.15.1.1), as addition of exogenous superoxide dismutase to malignant cells caused a normal reaction. We wish to suggest that this test in combination with the routine histology may be exploited for the diagnosis of polyps in premalignant conditions.

Adenocarcinoma↗

PubMed1989

[Studies on association between the ATL and the development of multiple malignant neoplasms--analysis of 1171 cases of hematological malignancies during the past 24 years].

A high incidence of multiple primary neoplasms has been observed in our patients with ATL in comparison to persons with other forms of hematologic malignancy who we have observed during the past 24 years (1963-1985). Five of 15 patients with ATL (33.3%) have had at least one other associated neoplasm in comparison to only 44 of 1156 patients with other forms of hematological malignancy (3.8%). The incidence figures for secondary neoplasms associated with the other hematologic malignancies were 4.3% (16/370) for acute non-lymphocytic leukemia (ANLL), 2.2% (2/90) for acute lymphocytic leukemia (ALL), 4.8% (1/21) for acute unclassifiable leukemia, 2.2% (5/225) for chronic myelogenous leukemia, 4.7% (2/43) for chronic lymphocytic leukemia, 5.9% (8/136) for malignant monoclonal gammopathy and 3.7% (10/271) for malignant lymphoma. The incidence of multiple neoplasms in patients with ATL in comparison to those with other hematological malignancies was significant (p less than 0.01 or p less than 0.001). The neoplasms associated with ATL have been adenocarcinoma of the thyroid or lung, and squamous cell carcinoma of the larynx, lip or lung. We identified ATL-derived factor (ADF) in the cytoplasm of the secondary neoplasms of the ATL patients by means of indirect immunofluoroscopy and immunohistochemical techniques utilizing anti-ADF antibody. We also identified ras p21 products in these neoplasms by means of p21 ras monoclonal antibody studies. The possibility that HTLV-I was the cause of the secondary neoplasms thus was investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokines↗

PubMed1995

Malignant melanoma and other second cutaneous malignancies in cutaneous T-cell lymphoma. The influence of additional therapy after total skin electron beam radiation.

BACKGROUND: Previous large studies have shown that patients with cutaneous T-cell lymphoma are at increased risk for basal cell carcinoma and squamous cell carcinoma, and anecdotal case reports have suggested an association with malignant melanoma. It has been postulated that the exposure of cutaneous structures to potentially carcinogenic therapies, such as ionizing radiation or alkylating agents, might be causally associated with the development of these second cutaneous malignancies, but, to date, no study has directly addressed this issue. The purpose of this study was to evaluate the occurrence of second cutaneous malignancies in a group of patients with cutaneous T-cell lymphoma treated with total skin electron beam therapy and to examine the additional effects of oral psoralen with UV-A phototherapy, topical mechlorethamine hydrochloride therapy, and further radiation therapy. One hundred sixty-four patients with cutaneous T-cell lymphoma who had received total skin electron beam therapy between 1974 and 1990 were identified, and information was abstracted from their records. RESULTS: Six patients developed malignant melanoma 12 to 95 months after total skin electron beam therapy. Of the six patients, three had received oral psoralen with UV-A as additional therapy and two had received topical mechlorethamine. None had received additional radiation therapy. Twenty-four patients developed more than 37 basal cell carcinomas and 34 squamous cell carcinomas from 11 months to more than 10 years after total skin electron beam therapy. Of the 24 patients, 15 had received oral psoralen with UV-A and 12 had received mechlorethamine as additional therapy. Additional radiation therapy had been administered to nine patients. During a median follow-up of 6 years, no patients died of any second cutaneous malignancy. CONCLUSION: We found a high rate of both melanoma and nonmelanoma skin cancer. The additional use of mechlorethamine or oral psoralen plus UV-A, but not radiation, was significantly associated with the development of basal cell carcinoma and squamous cell carcinoma, but not malignant melanoma.

Adult↗

PubMed1994

Cytogenetic analysis and morphology of malignant nuclear vlimata. The life cycle of malignant cells.

The karyotype of malignant nuclear vlimata (NVs) was investigated with the in situ and chromosomal spreading techniques. NV metaphases were recognised by the head with tail morphology, kept in situ and evaluated by the chromosomal spreading technique. It was shown that malignant NVs were produced by random, uncontrolled meiosis. NVs contain and carry single, hypodiploid, haploid, hypohaploid, hyperdiploid and atypical sets of chromosomes. NVs are unstable parasitic cellular elements, invading the cytoplasm or the nucleus of host cells, extruding and implanting their chromosomes in the host cell upon contact. Within a malignant cell culture, NVs play the role of chromosomal donors and host cells of chromosomal recipients. NVs were identified as episomatic on host cell nuclei or incorporated into host cell metaphases. The observations are discussed in terms of fertilization, viral infection and apoptosis. Comparison of malignant NVs with phytohaemagglutinin (PHA)-activated lymphocytic NVs is provided, as well as the life cycle of the malignant cells as follows: [Formula see text] cells (Logothetou-Rella, 1993). Phytohaemagglutinin (PHA)-activated lymphocytes also produced NVs by meiosis, carrying hypodiploid, haploid and hypohaploid sets of chromosomes (Logothetou-Rella, 1994a). In this study the cytogenetic analysis and morphology of malignant NVs are investigated, using a) the in situ cytogenetic technique, and b) the chromosomal spreading technique.

Aneuploidy↗

PubMed1996

Epstein-Barr virus latent membrane protein-1 oncogene deletions: correlations with malignancy in Epstein-Barr virus--associated lymphoproliferative disorders and malignant lymphomas.

LMP-1, an Epstein-Barr viral (EBV) latency protein, is considered a viral oncogene because of its ability to transform rodent fibroblasts in vivo and render them tumorigenic in nude mice. In human B cells, EBV LMP-1 induces DNA synthesis and abrogates apoptosis. LMP-1 is expressed in EBV-transformed lymphoblastoid cell lines, nasopharyngeal carcinoma (NPC), a subset of Hodgkin's disease (HD), and in EBV-associated lymphoproliferative disorders (EBV-LPDs). Recently, focused deletions near the 3' end of the LMP-1 gene (del-LMP-1, amino acids 346-355), in a region functionally related to the half-life to the LMP-1 protein, have been reported frequently in human immunodeficiency virus (HIV)-associated HD (100%) and EBV+ Malaysian and Danish peripheral T-cell lymphomas (100%, 61% respectively), but less frequently in cases of HD not associated with HIV (28%, 33%) and infectious mononucleosis (33%). To further investigate the potential relationship of del-LMP-1 to EBV-LPDs associated with immunosuppression or immunodeficiency, we studied 39 EBV-associated lymphoproliferations (10 benign, 29 malignant) from four distinct clinical settings: posttransplant (4 malignant, 1 reactive); HIV+ (18 malignant, 2 reactive); nonimmunodeficiency malignant lymphoma (ML) (7 cases); and sporadic EBV infection with lymphoid hyperplasia (7 cases). The presence of EBV within lymphoid cells was confirmed by EBV EBER1 RNA in situ hybridization or by polymerase chain reaction (PCR) analysis. EBV strain type and LMP-1 deletion status were determined by PCR. EBV strain types segregated into two distinct distributions: HIV+ (9 A; 11 B) and non-HIV (19 A, 0 B), consistent with previous reports. Overall, del-LMP-1 were found in 1 of 5 (20%) Burkitt lymphomas (BL); 17 of 24 (71%) aggressive non-Hodgkin's lymphoma (agg-NHL), and 2 of 10 (20%) reactive lymphoid proliferations. Of the agg-NHLs, del-LMP-1 were present in 4 of 4 PT-ML (100%); 10 of 15 HIV+ ML (67%); and 3 of 5 nonimmunodeficiency malignant lymphoma (ML, 60%). A total of 2 of 7 (28%) sporadic EBV-associated lymphoid hyperplasias contained a del-LMP-1. All del-LMP-1 were identical by DNA sequence analysis. No correlation was identified between the presence of del-LMP-1 and the EBV strain type observed. The high incidence of del-LMP-1 observed in agg-NHLs (71%), in contrast to the relatively low incidence observed in reactive lymphoid proliferations (28%), suggests that the deleted form may be preferentially selected in lymphomatous processes. All posttransplant agg-NHLs contained a del-LMP-1, and a similar frequency of del-LMP-1 was observed in both HIV-associated ML (66%) and nonimmunodeficiency ML (60%), suggesting that impairment of immune function alone is not a requirement for the expansion of malignant cells infected by EBV stains containing the deleted LMP-1 gene.

Adolescent↗