Biomedical subjects

D M Knowles

Publications and source records attributed to D M Knowles.

At least 109 records · Page 6Linked to original sources

PubMed1992

Molecular pathogenesis of HIV-associated lymphomas.

The data presented here indicate that the pathogenesis of AIDS-NHL is variably associated with multiple genetic alterations including monoclonal EBV infection, oncogene activation (c-myc, N-, Ki-ras) and tumor suppressor gene (p53) inactivation. Up to three (3 cases) or four (1 case) different lesions have been observed in the same tumor. The distribution of these lesions among the various histotypes is heterogeneous, although some preferential associations have been found either between lesion and histotype or between lesions. The most notable case involves p53 mutations/loss that is exclusively associated with the SNCC lymphoma subtype. Since alterations of the c-myc gene occur at very high frequency in this same histotype it is possible that both lesions may be required for the pathogenesis of the BL phenotype. The consistent negativity of p53 lesions in other NHLs associated or non associated with HIV infection (18) reinforces this hypothesis. Finally, we note that the frequency of p53 mutations is significantly higher in AIDS-BL than in non HIV-related BL (18), although the significancy of this difference remains to be assessed. This study confirms the relatively low frequency of EBV infection in systemic AIDS-NHL in general, but reinforces the notion that EBV may be required for the pathogenesis of AIDS-LC-IBP, as recently suggested by the high frequency of EBV positivity in primary CNS AIDS-NHL which are mostly represented by LC-IBP (2). Conversely, the low frequency of EBV sequences in the AIDS-SNCC lymphomas appears similar to that observed in sBL. Only in a small minority of cases were ras oncogene mutations found, mostly associated with the BL type.(ABSTRACT TRUNCATED AT 250 WORDS)

Genes, myc↗

PubMed1992

The kinetics and temporal expression of T-cell activation-associated antigens CD15 (LeuM1), CD30 (Ki-1), EMA, and CD11c (LeuM5) by benign activated T cells.

Cell surface antigens, including CD71 (T9), CD38 (T10), HLA-DR, CD25 (IL2-R), CD15 (LeuM1), CD30 (Ki-1), epithelial membrane antigen (EMA), and CD11c (LeuM5), have been identified on the surface of neoplastic T-cells. The significance of this expression is unknown since the expression of these antigens by benign T cells has not been fully investigated. In this study the kinetics, temporal relation and hierarchy of expression of these eight cell surface antigens by purified normal peripheral blood T cells following activation with phytohemagglutinin (PHA) were investigated using one- and two-color flow cytometry. All eight antigens were expressed in a hierarchical manner following activation of normal peripheral blood T cells with PHA. The sequence of antigen expression and the initial time point of this expression was: CD38, < 24 h; CD71, CD25, 24 h; EMA, HLA-DR, CD15, 48-72 h; CD30, 72 h; and CD11c, 96-120 h. The maximum percentage of T cells expressing each antigen and the time point of maximum expression was: CD38 96% at 14 and 17 days; CD71 88%, CD25 94%, EMA 55%, and CD30 31% at 96 h; CD15 56% at 120 h; HLA-DR 30% at 168 h; and CD11c 42% at 240 h. The expression of these 8 antigens clustered into six distinct immunophenotypic constellations: Group I: None; Group II: CD38 with CD71 and/or CD25; Group III: CD38, CD71, CD25 with HLA-DR, CD15 and/or EMA; Group IV: CD38, CD71, CD25, EMA, HLA-DR with CD15, CD30 and/or CD11c; Group V: CD38, CD25, CD11c with CD71, EMA and/or HLA-DR; Group VI: CD38 with CD25 and/or CD11c. Finally, EMA and CD11c were preferentially expressed by CD4 and CD8 T cells, respectively. In summary, these results demonstrate that all eight antigens (1) are associated with T-cell activation, (2) are expressed in a hierarchical manner following activation, and (3) that this expression clusters into distinct immunophenotypic constellations.

Antigens↗

PubMed1992

T-cell activation-associated antigen expression by neoplastic T-cells.

In this study, a clinicopathologically and immunophenotypically diverse group of T-cell neoplasms were evaluated by one- and two-color flow cytometry and/or immunohistochemistry for the presence of eight antigens (T10, T9, IL2-R, EMA, HLA-DR, LeuM1, Ki-1, and LeuM5) which are expressed in a hierarchical manner by phytohemagglutinin (PHA)-activated benign T cells. We found that 70 of the 72 T-cell neoplasms (97%) expressed at least one of these eight T-cell activation-associated antigens (T-AAgs) and that the number and type of T-AAgs expressed by the neoplastic T cells varied according to the clinicopathologic category of T-cell neoplasia. All 5 T-cell lymphoblastic malignancies expressed T10 and T9; 2 also expressed LeuM1. Twelve of 14 (86%) T cell chronic lymphocytic leukemias (T-CLL) expressed two to four T-AAgs, most frequently T10 (86%) and HLA-DR (79%). The 26 cutaneous T-cell lymphomas (CTCL) expressed between 2 and 5 T-AAgs, most commonly T9 (92%) and HLA-DR (92%), and least often T10 (12%) and EMA (15%). Twenty-six of 27 (96%) peripheral T-cell lymphomas (PTCL) expressed more than 4 T-AAgs. Each of the T-AAgs were expressed by between 22% (LeuM5) and 85% (T9) of the PTCLs. Some T-AAgs were preferentially expressed by the PTCLs in association with other T-AAgs, such as EMA in association with IL2-R and Ki-1. In addition, LeuM5 was preferentially expressed by CD4- CD8+ T-cell neoplasms. However, only 19 of the 72 (26%) T-cell neoplasms (3/5 lymphoblastic malignancies, 3/14 CLLs, 0/26 CTCLs, 13/27 PTCLs) expressed T-AAg immunophenotypic profiles paralleling those expressed by normal peripheral blood T cells activated in vitro with PHA. These results suggest that T-AAg expression by neoplastic T cells does not often mirror the hierarchical order of expression by activated benign T cells, implying that neoplastic T cells do not usually represent the precise malignant counterpart of activated benign, normal T cells.

Antibodies, Monoclonal↗

PubMed1992

The bcl-2 gene translocation is undetectable in Hodgkin's disease by Southern blot hybridization and polymerase chain reaction.

B-cell associated antigens are frequently expressed by the Reed-Sternberg (RS) cells of lymphocyte predominance (LP) Hodgkin's disease (HD) and are sometimes expressed by those of nodular sclerosis (NS) and mixed cellularity (MC) HD. Clonal immunoglobulin gene rearrangements have been detected in some HD cases as well. These findings suggest that at least some cases of HD may be of B-cell derivation. Rearrangements of the bcl-2 gene, associated with the t(14;18)(q32;q21) are present in more than 75% of follicular and 30% of diffuse lymphomas of B-cell origin, suggesting that this translocation plays an important role in B-cell lymphomagenesis. In this study, we investigated 34 cases of HD (10 LP, 14 NS, and 10 MC) for bcl-2 gene rearrangements to determine if this B-cell lymphoma-associated translocation also plays a role in the pathogenesis of HD. The cases of HD were analyzed by Southern blot hybridization, using DNA probes that detect the major and minor breakpoint cluster regions and a 5'bcl-2 breakpoint region recently cloned and found to be involved in B-cell chronic lymphocytic leukemia, and by the polymerase chain reaction (PCR), using oligonucleotides capable of amplifying and detecting the major breakpoint region (mbr) and minor cluster region (mcr) breakpoint regions in t(14;18). bcl-2 translocations were not detected in any of the 34 cases of HD by Southern blot hybridization or by PCR. This is in spite of the fact that RS cells expressing B-cell-associated antigen CD20 were detectable in 7/8 cases of LP HD and 6/24 cases of NS and MC HD with monoclonal antibody L26. Therefore, these results indicate that the bcl-2 gene translocation does not play an important role in the pathogenesis of HD and did not provide evidence for the B-cell origin of HD.

Base Sequence↗

PubMed1991

Autoantibody-associated cross-reactive idiotype-bearing human B lymphocytes: distribution and characterization, including Ig VH gene and CD5 antigen expression.

Monoclonal antibodies (MoAbs) specific for autoantibody associated cross-reactive idiotypes (CRIs) frequently recognize the Igs of neoplastic B cells in patients with chronic lymphocytic leukemia (CLL) and/or Waldenstrom's macroglobulinemia. Very little is known regarding the normal B cells expressing CRIs (CRI-positive B cells). Using a variety of MoAbs against CRIs we investigated the distribution and topographic localization of CRI-positive B cells in normal adult human lymphoid tissues. We found that CRI-positive B cells represent a significant B-cell subpopulation expressing surface IgM (greater than 90%), IgG (approximately 5%), or IgA (approximately 2%). CRI-positive B cells are homogeneously distributed throughout all lymphoid tissues, accounting for 10% to 15% of all B lymphocytes, with the exception of the thymus, in which they represent the predominant B cell population. Immunophenotypic studies showed (1) that a small subpopulation (3.7% +/- 0.8%) of CRI-positive B cells are activated in vivo, based on CD25 and CD38 antigen expression; and (2) that approximately 50% of CRI-positive B cells express the 67-Kd pan-T-lymphocyte CD5 antigen, suggesting that the CRI-positive B-cell subset and the recently described CD5-positive B-cell subset are closely related. This hypothesis is supported by the fact that CRI-positive B cells produce oligo or polyreactive Igs, which are a characteristic feature of CD5-positive B cells, and also by the fact that both B-cell subpopulations appear to use similar and restricted Ig VH gene family members.

Antibodies, Monoclonal↗

PubMed1991

p53 mutations in human lymphoid malignancies: association with Burkitt lymphoma and chronic lymphocytic leukemia.

We have investigated the frequency of p53 mutations in B- and T-cell human lymphoid malignancies, including acute lymphoblastic leukemia, the major subtypes of non-Hodgkin lymphoma, and chronic lymphocytic leukemia. p53 exons 5-9 were studied by using genomic DNA from 197 primary tumors and 27 cell lines by single-strand conformation polymorphism analysis and by direct sequencing of PCR-amplified fragments. Mutations were found associated with (i) Burkitt lymphoma (9/27 biopsies; 17/27 cell lines) and its leukemic counterpart L3-type B-cell acute lymphoblastic leukemia (5/9), both of which also carry activated c-myc oncogenes, and (ii) B-cell chronic lymphocytic leukemia (6/40) and, in particular, its stage of progression known as Richter's transformation (3/7). Mutations were not found at any significant frequency in other types of non-Hodgkin lymphoma or acute lymphoblastic leukemia. In many cases, only the mutated allele was detectable, implying loss of the normal allele. These results suggest that (i) significant differences in the frequency of p53 mutations are present among subtypes of neoplasms derived from the same tissue; (ii) p53 may play a role in tumor progression in B-cell chronic lymphocytic leukemia; (iii) the presence of both p53 loss/inactivation and c-myc oncogene activation may be important in the pathogenesis of Burkitt lymphoma and its leukemic form L3-type B-cell acute lymphoblastic leukemia.

Base Sequence↗

PubMed1991

Intracerebral Hodgkin's disease in a human immunodeficiency virus-seropositive patient.

Intracerebral involvement of Hodgkin's disease (HD) is rarely described, with only 42 cases in the literature. Since the outbreak of the acquired immune deficiency syndrome (AIDS) epidemic, there has been an increasing number of human immunodeficiency virus (HIV)-infected (HIV+) persons who have diffuse non-Hodgkin's lymphoma and, more recently, atypical aggressive HD. The authors report the case of a patient with a history of intravenous drug abuse (IVDA) and Stage IVB HD who, after a drug-induced clinical remission, had intracerebral mixed-cellularity HD. This appears to be the first report of intracerebral HD in a person who is HIV+.

Adult↗

PubMed1991

Detection and characterization of human T-cell lymphotropic virus type I (HTLV-I) associated T-cell neoplasms in an HTLV-I nonendemic region by polymerase chain reaction.

Human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukemia/lymphoma (ATLL) occurs endemically in southwestern Japan, the Caribbean, and West Africa, but occurs sporadically in most of the rest of the world. However, because ATLL and non-HTLV-I associated T-cell neoplasms share overlapping clinicopathologic features, the prevalence of ATLL in nonendemic regions is unknown. In this study, 75 T-cell neoplasms randomly procured from the metropolitan New York City area were examined by polymerase chain reaction (PCR) for the presence of integrated HTLV-I proviral sequences. HTLV-I genomic sequences were detected by PCR in 6 of the 75 cases (8%); this result was confirmed by Southern blot hybridization. The clinicopathologic features of the HTLV-I positive and HTLV-I negative T-cell neoplasms were then compared. Although the clinicopathologic features of patients from these two groups overlapped, some findings were more commonly associated with HTLV-I positive neoplasms. Five of the six patients with HTLV-I positive neoplasms were from HTLV-I endemic areas, five were black, five were women, and five were less than 45 years of age, while the majority of the patients with HTLV-I negative T-cell malignancies were elderly white men. The incidence of hypercalcemia and lytic bone lesions was significantly more common among patients with HTLV-I positive T-cell neoplasms (P less than .001 and P = .004, respectively). The immunophenotypes of the HTLV-I positive and negative tumors were similar; however, all HTLV-I positive neoplasms were CD7 negative (P less than .001). In summary, our findings: (1) demonstrate the special clinicopathologic and immunophenotypic features of HTLV-I positive T-cell neoplasms, (2) suggest that most of the rare cases of HTLV-I-associated T-cell neoplasms occurring in HTLV-I nonendemic areas are actually endemic cases; and (3) that PCR is a sensitive, clinically useful technique for identifying HTLV-I associated T-cell neoplasms.

Adult↗

PubMed1991

Epstein-Barr virus infection precedes clonal expansion in Burkitt's and acquired immunodeficiency syndrome-associated lymphoma.

The Epstein-Barr virus (EBV) is associated with distinct forms of human lymphoid malignancies, including the endemic (eBL) and sporadic forms of Burkitt's lymphoma (sBL) and acquired immunodeficiency syndrome-associated non-Hodgkin lymphoma (AIDS-NHL). However, whether EBV has a pathogenetic role in these tumors or is a passenger virus has not been conclusively demonstrated. One element to distinguish between these two possibilities is to determine whether EBV infection has preceded and, thus, possibly contributed to clonal expansion, or whether infection has occurred after clonal expansion and thus is unlikely to contribute to pathogenesis. Toward this end we analyzed the structure of the heterogeneous genomic termini of EBV as markers of clonal infection in a panel of eBL (11 cases), sBL (9 cases), and AIDS-NHL (10 cases) biopsies. We show that EBV termini are uniformly clonal in sBL, eBL, and AIDS-NHL, strongly suggesting that EBV infection has preceded and, thus, most likely contributed to clonal expansion in these malignancies.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Lymphoma, motor neuron diseases, and amyotrophic lateral sclerosis.

We studied 9 patients with motor neuron disease and lymphoma. The following several observations have not been recognized in the past: (1) Motor neuron syndromes are associated with either Hodgkin's disease or non-Hodgkin's lymphoma. (2) The syndromes are not restricted to lower motor neuron disorders; 8 of 9 patients had definite or probable upper motor neuron signs as well, qualifying for the diagnosis of amyotrophic lateral sclerosis. Corticospinal tracts were affected in both postmortem examinations. (3) The combination of motor neuron disease and lymphoma is often accompanied by paraproteinemia (3 of 7 patients studied), increased cerebrospinal fluid protein content (6 of 9 patients), and cerebrospinal fluid oligoclonal bands (3 of 9 patients). (4) In 2 patients, asymptomatic non-Hodgkin's lymphoma was found only because the discovery of paraproteinemia gave impetus to examine the bone marrow. (5) Patients with both upper and lower motor neuron signs (amyotrophic lateral sclerosis) may show physiological evidence of conduction block in peripheral nerves or autopsy abnormalities in peripheral nerves. The cause of this syndrome is not known. Both lymphoma and motor neuron disease could have a common cause, possibly a retroviral infection. The frequency of paraproteinemia suggests that an immunological disorder may play a role in the pathogenesis of the neurological disorder.

Aged↗

PubMed1991

VH gene usage in humans: biased usage of the VH6 gene in immature B lymphoid cells.

Preferential usage of JH-proximal VH genes has been demonstrated in immature murine B cell repertoires. To determine whether this phenomenon is also evident in human repertoires, we studied utilization of VH6, the most JH-proximal human VH gene. Examination of VH gene usage in a panel of precursor B cell acute lymphoblastic leukemia samples indicated that 15% of the IgH rearrangements utilized VH6. VH6 is a single-member family in a total repertoire of 100-200 VH genes; thus, if usage were purely random, one would expect VH6 rearrangement frequency to be less than 1%. Analysis of VH gene usage in normal lymphoid tissues also revealed biased usage of VH6. VH6 was preferentially utilized in 16- to 24-week-old fetal liver as compared to adult peripheral blood mononuclear cells or spleen. Possible implications of the conservation of preferential usage of JH-proximal genes in both immature murine and human repertoires are discussed.

Adult↗

PubMed1991

Membrane glycoprotein changes associated with anthracycline resistance in HL-60 cells.

The glycoproteins on the surface of HL-60/S wild-type, drug-sensitive human leukemia cells and HL-60/AR anthracycline-resistant cells which do not overexpress the P-glycoprotein, were characterized by labeling with [35S]-methionine, NaB[3H4], phosphorus 32, or sodium iodide I 125. HL-60/S and HL-60/AR cell lysates and membrane fractions tagged with [35S]-methionine or phosphorus 32 showed no significant differences in their protein patterns as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by autoradiography. HL-60/S cells labeled with NaB[3H4] yielded glycoproteins that were smeared predominantly in the molecular-weight range of 210,000 and 160,000 Da, with pI values ranging between pH 4 and pH 4.4. In contrast, NaB[3H4]-labeled HL-60/AR cells showed 7-8 discrete glycoproteins within a molecular-weight range of 170,000 and 140,000 Da, with pI values also ranging between pH 4 and pH 4.4. In addition, [3H]-glucosamine incorporation into HL-60/S and HL-60/AR cells revealed that the latter showed lower uptake of [3H]-glucosamine than did the former. Following treatment with tunicamycin, [3H]-glucosamine uptake in HL-60/S cells decreased, whereas that in HL-60/AR cells remained unchanged. Surface-membrane radioiodination of HL-60/S and HL-60/AR cells showed two distinct protein electrophoretic patterns, with differences being observed in both the high-(220-95 kDa) and low-molecular-weight ranges (21 kDa). Flow cytometric analysis of HL-60/S and HL-60/AR cells using myeloid and lymphoid antigen-specific antibodies demonstrated no antigenic differences between HL-60/S and HL-60/AR cells. HL-60/S cells incubated in the presence of tunicamycin, an inhibitor of N-linked glycosylation, or the protein kinase C agonist phorbol 12-myristate 13-acetate (PMA) developed a glycoprotein pattern similar to that observed in HL-60/AR cells. In addition, tunicamycin treatment of HL-60/S cells decreased daunorubicin (DNR) retention and altered its intracellular distribution as compared with that in HL-60/AR cells. These data indicate that HL-60/AR cells do not possess either de novo or amplified high-molecular-weight surface-membrane proteins; instead, existing proteins are hypoglycosylated. These results also show that HL-60/AR cells exhibit the multidrug-resistant phenotype in association with altered membrane glycoproteins of both high (220-95 kDa) and low molecular weight (21 kDa), but without overexpression of the P-glycoprotein. Furthermore, in HL-60/S cells, the multidrug-resistant phenotype is partially inducible by inhibition of N-linked glycosylation of cell-surface proteins.

Antibiotics, Antineoplastic↗

PubMed1991

The B-cells that express anti-MAG antibodies in neuropathy and non-malignant IgM monoclonal gammopathy belong to the CD5 subpopulation.

B-cells that express monoclonal IgM anti-MAG antibodies (M-protein) in a patient with neuropathy and non-malignant IgM monoclonal gammopathy were studied by flow cytometry to determine if they bear the CD5 cell surface antigen. The CD5+ antigen is expressed on a subpopulation of B-cells which has been implicated in the secretion of autoantibodies and development of B-cell chronic lymphocytic leukemia (B-CLL). The monoclonal anti-MAG antibodies secreting B-cells were identified by a mouse monoclonal antibody to M-protein idiotype. Cytofluorometric analysis revealed that approximately 62% of the idiotype-positive B-lymphocytes expressed the CD5 antigen. The result of this study indicate that monoclonal anti-MAG antibodies may be secreted by CD5+ B-cells, and that B-cells in some cases of non-malignant IgM monoclonal gammopathy may be phenotypically similar to B-CLL cells.

Antibodies↗

PubMed1991

bcl-1 rearrangement. Frequency and clinical significance among B-cell chronic lymphocytic leukemias and non-Hodgkin's lymphomas.

The authors investigated the structural organization of the bcl-1 locus, a putative oncogene associated with reciprocal chromosomal translocation t(11;14), by Southern blot hybridization analysis and its frequency, distribution, and prognostic significance in a panel of 156 clinically and pathologically well-defined B-cell chronic lymphocytic leukemias (CLLs) and non-Hodgkin's lymphomas (NHLs). The authors detected bcl-1 rearrangements in only 2 of 42 CLLs and 4 of 114 NHLs, specifically 3 of 29 diffuse small lymphocytic and 1 of 10 diffuse small cleaved cell and none of 5 diffuse intermediate lymphocytic, 13 follicular predominantly small cleaved, 17 follicular mixed small cleaved and large cell, 4 diffuse mixed small and large cell, 26 diffuse large cell, and 10 diffuse small noncleaved cell lymphomas. None of seven cases of Rai stage III or IV CLL or seven diffuse large cell lymphomas occurring as Richter's syndrome exhibited bcl-1 rearrangements. In conclusion, the bcl-1 locus rearranges in only about 4% of B-cell CLLs and NHLs, is predominantly rearranged in low-grade B-cell neoplasms, and does not appear to be preferentially associated with those occasional CLLs and low-grade NHLs displaying clinical aggressiveness, advanced clinical stage, or large cell transformation (Richter's syndrome). Therefore the demonstration of bcl-1 rearrangement does not appear to have clinically useful prognostic significance.

Blotting, Southern↗

PubMed1990

Down-regulation of LFA-1 adhesion receptors by C-myc oncogene in human B lymphoblastoid cells.

The function of the c-myc gene and its role in tumorigenesis are poorly understood. In order to elucidate the role of c-myc oncogene activation in B cell malignancy, the phenotypic changes caused by the expression of c-myc oncogenes in human B lymphoblastoid cells immortalized by Epstein-Barr virus were analyzed. C-myc oncogenes caused the down-regulation of lymphocyte function-associated antigen-1 (LFA-1) adhesion molecules (alpha L/beta 2 integrin) and loss of homotypic B cell adhesion in vitro. Down-regulation of LFA-1 occurred by (i) posttranscriptional modulation of LFA-1 alpha L-chain RNA soon after acute c-myc induction, and (ii) transcriptional modulation in cells that chronically express c-myc oncogenes. Analogous reductions in LFA-1 expression were detectable in Burkitt lymphoma cells carrying activated c-myc oncogenes. Since LFA-1 is involved in B cell adhesion to cytotoxic T cells, natural killer cells, and vascular endothelium, these results imply functions for c-myc in normal B cell development and lymphomagenesis.

B-Lymphocytes↗

PubMed1990

B cell small lymphocytic lymphoma and chronic lymphocytic leukemia with peripheral neuropathy: two cases with neuropathological findings and lymphocyte marker analysis.

Two patients with lymphoproliferative disorders developed peripheral neuropathy and neoplastic lymphocytic nerve infiltrates. One of these patients, with B cell small lymphocytic lymphoma, presented with a chronic axonal neuropathy. CD22+, CD5- cells were identified in the epineurium. The other patient with chronic lymphocytic leukemia of 3 years duration developed a mixed axonal and demyelinating neuropathy. CD22+ and CD5+ cells were observed in the endoneurium. While the cause of the neuropathy in these two cases is unknown, intraneural or systemic autoantibody production may have led to the development of disease.

Aged↗

PubMed1990

Lymphoid hyperplasia and malignant lymphoma occurring in the ocular adnexa (orbit, conjunctiva, and eyelids): a prospective multiparametric analysis of 108 cases during 1977 to 1987.

We performed a prospective multiparametric correlative clinical, histopathologic, and immunologic analysis of 117 ocular adnexal lymphoid proliferations developing in 108 patients between October 1977 and July 1987. The ocular adnexal lymphoid proliferations were distributed among the 108 patients as follows: orbit 69 (64%), conjunctiva 30 (28%), and eyelids nine (8%). The 117 ocular adnexal lymphoid proliferations were classified as follows: polyclonal lymphoid hyperplasia, 32 (22 orbit, nine conjunctiva, one eyelid) (27%); monoclonal B cell lymphoma, 81 (48 orbit, 25 conjunctiva, eight eyelid) (69%); null cell lymphoma, one (orbit) (1%); and histologically indeterminate, three (one each: orbit, conjunctiva, eyelid) (3%). Patients presenting with ocular adnexal polyclonal lymphoid hyperplasia and monoclonal B cell lymphoma, and patients developing unilateral and bilateral ocular adnexal lymphoid proliferations did not differ significantly with respect to age, sex, presenting complaints, duration of symptoms, or ophthalmic findings. Classifying ocular adnexal lymphoid proliferations into benign and malignant categories by histopathologic criteria and into polyclonal and monoclonal B cell categories by immunophenotypic criteria was not useful in predicting eventual outcome, including the occurrence of extraocular lymphoma. However, the clinicopathologic characteristics did differ according to the anatomic site of involvement and histopathology of the ocular adnexal lymphoid proliferations. Lymphoid infiltrates of the conjunctiva were associated with a lower incidence of extra-ocular lymphoma (20%) than were those of the orbit and eyelid, 35% and 67%, respectively (statistically significant, P less than .03). Ocular adnexal small lymphocytic and intermediate lymphocytic lymphomas were less often associated with extra-ocular lymphoma than were ocular adnexal lymphomas of all other histologic types, 27% and 46%, respectively (P less than .09). However, the single most important and statistically significant prognostic factor in these patients was the extent of disease at the time of presentation with an ocular adnexal lymphoid proliferation (P less than .001). Eighty-six percent of patients presenting with a unilateral or bilateral clinical stage lE ocular adnexal lymphoid proliferation, regardless of the histopathology or the immunophenotype, had a benign indolent clinical course and failed to develop ocular or extra-ocular lymphoma during a median follow-up period of 51 months. The results of this study substantially improve our understanding of extranodal small lymphocytic proliferations in general, and those of the ocular adnexa in particular.

Adolescent↗

PubMed1990

Intracerebral solitary plasmacytoma.

We report a rare occurrence of intraparenchymal plasmacytoma and review the literature. The clonal nature of the neoplasm is demonstrated by immunohistochemical and molecular techniques. The importance of the latter techniques in ruling out other pathological entities is stressed.

Blotting, Southern↗