Rachele Volpe

Human immunodeficiency virus-associated systemic lymphomas may be subdivided into two main groups according to Epstein-Barr viral latent gene expression.

PURPOSE We report a pathologic characterization of human immunodeficiency virus (HIV)-associated systemic lymphomas, including the association of Epstein-Barr virus (EBV) in different categories. PATIENTS AND METHODS Eighty-seven HIV-associated non-Hodgkins lymphoma (NHL) were classified according to classic NHL classification and a recent description of morphologic variants of high-grade B-cell NHL. Seventy-one cases were immunophenotypically-genotypically characterized, whereas, in 49 representative cases, the association of EBV was assessed by nonisotopic in situ hybridization (ISH) and the immunohistochemical demonstration of latent membrane protein-1 (LMP-1). In addition, 14 Hodgkins disease (HD) cases, occurring in patients with HIV infection, were investigated for the frequency of LMP-1 expression. RESULTS Most lymphomas were of B-cell derivation and showed a blastic cell morphology, with (1) small noncleaved cells (SNCCs; 36 cases), (2) large noncleaved cells (10 cases), and (3) immunoblasts, usually polymorphic (12 cases). Moreover, 12 cases were classified as anaplastic large-cell (ALC) Ki-1-positive (Ki-1+) lymphoma. Combined ISH studies (for viral DNA and EBV RNA [EBER]) and immunohistologic demonstration of LMP-1 suggested that there were differences in viral latent gene expression between ALC Ki-1+ or immunoblastic lymphomas (usually EBV+, LMP-1+), and EBV-infected cells of SNCC lymphomas, which did not show LMP-1 expression. A high proportion (10 of 14) of LMP-1+ HD cases was found. CONCLUSION Differences in EBV association and LMP-1 expression were found between a major group of HIV-associated systemic NHL with blastic cell morphology, including SNCC lymphoma and its variants, and anaplastic cell lymphomas. A proportion of immunoblastic (polymorphic) lymphomas was different in viral latent gene expression from other blastic cell systemic lymphomas. It is concluded that only a group of these lymphomas (most ALC Ki-1+ and HD cases, along with a nonnegligible fraction of immunoblastic lymphomas) seems to be linked etiopathologically to EBV.

Burkitt's lymphoma in adults with and without human immunodeficiency virus infection: A single-institution clinicopathologic study of 75 patients

Burkitts lymphoma (BL) accounts for 1‐2% of all cases of non‐Hodgkins lymphoma (NHL) in the general population and for 35‐40% in the setting of human immunodeficiency virus (HIV) infection. The authors report a 9‐year single‐institution experience with 75 adult BL patients (46 with and 29 without HIV infection) and compare the clinical and pathologic features of the disease in the two groups of patients.

Establishment and characterization of EBV‐positive and EBV‐negative primary effusion lymphoma cell lines harbouring human herpesvirus type‐8

In this study we report on the establishment and characterization of two novel lymphoma cell lines (CRO‐AP/3 and CRO‐AP/5) which carry infection by human herpesvirus type‐8 (HHV‐8) and have derived from AIDS‐related primary effusion lymphoma (PEL). These two cell lines are representative of different virologic subtypes of PEL, i.e. HHV‐8+/EBV− PEL in the case of CRO‐AP/3 and HHV‐8+/EBV+ PEL in the case of CRO‐AP/5. Consistent with the diagnosis of PEL, both CRO‐AP/3 and CRO‐AP/5 expressed indeterminate (i.e. non‐B, non‐T) phenotypes although immunogenotypic studies documented their B‐cell origin. Both cell lines are devoid of genetic lesions of c‐MYC, BCL‐2 and p53 as well as gross rearrangements of BCL‐6. Detailed histogenetic characterization of these novel PEL cell lines suggests that PEL may derive from a post‐germinal centre B cell which has undergone pre‐terminal differentiation. The CRO‐AP/3 and CRO‐AP/5 cell lines may provide a valuable model for clarifying the pathogenesis of PEL. In particular, these cell lines may help understand the relative contribution of HHV‐8 and EBV to PEL growth and development and may facilitate the identification of recurrent cytogenetic abnormalities highlighting putative novel cancer related loci relevant to PEL.

A clinicopathologic study of lymphoid neoplasias associated with human immunodeficiency virus infection in Italy

The clinicopathologic features of 45 human immunodeficiency virus (HIV)‐infected patients (mainly intravenous drug users [IVDU]) with lymphoid neoplasias seen from September 1984 through July 1990 at an Italian cancer center are reviewed. Thirty‐five had systemic non‐Hodgkins lymphoma (NHL), and ten had Hodgkins disease (HD). Histologically, 27 NHL cases were intermediate grade (five cases) or high grade (22 cases, 14 of the small noncleaved cell type), according to the Working Formulation. Eight NHL cases, including four anaplastic large cell (ALC) BerH2 (CD30)‐positive lymphomas, were in the miscellaneous group. Immunohistologic and/or gene rearrangement analysis showed the B‐cell origin of 20 of the 24 NHL cases studied. At presentation, 71% of NHL patients had advanced stages (Stage III or IV), and 85% had extranodal disease (predominantly gastrointestinal tract and marrow). Of the 23 patients evaluable for treatment, only seven had a complete clinical response after lymphoma therapy; the median survival of 34 evaluable patients was 22 months after the diagnosis of NHL. Fifteen patients died; most deaths were attributable to progressive lymphoma and opportunistic infections. As with NHL, advanced disease, extranodal involvement, aggressive histologic findings, and poor response to therapy were also observed in patients with HD. This study shows that lymphoid neoplasias occurring in Italian IVDU with HIV infection and those previously reported in North American homosexual men with HIV infection share similar clinicopathologic features. However, some features such as the absence of history of Kaposis sarcoma at diagnosis, the lack of detection of primary brain and rectal NHL, and the occurrence of B‐cell ALC BerH2 (CD30)‐positive NHL were observed uniquely in this series of patients.

Histopathologic, immunophenotypic, and genotypic analysis of Ki‐1 anaplastic large cell lymphomas that express histiocyte‐associated antigens

CD30/Ki‐1 antigen expression in 243 cases of malignant lymphomas was examined using Ber‐H2 monoclonal antibody. Among them 20 cases were categorized as Ki‐1 anaplastic large cell lymphoma. in two of these cases histiocyte‐associated markers were also expressed. in these cases histopathologic and extensive in situ immunophenotypic analyses were used with genotypic studies in the determination of cell lineage. A sinusoid histologic pattern of involvement with partial lymph node infiltration by pleomorphic neoplastic cells was noticed in the nodes from both patients. Solid areas of node replacement resembling metastatic carcinoma were seen in Patient 1. Immunohistologically, tumor cells of both cases were positive for CD30, CD25, CD71, LN3 (HLA‐DR), EMA, CD45, CD74, vimentin, alpha‐1‐antichymotrypsin, and CD68. Patient 1 was also CD45RO+, CD43+, whereas Patient 2 was positive for alpha‐1‐antitrypsin and CD4 tumor cells. Genotypic studies revealed that TCRβ and TCRγ chain genes were clonally rearranged in Patient 1, whereas no rearrangements were detected in Patient 2. This study supports the view that some Ki‐1 anaplastic large cell lymphomas may express multiple histiocyte‐associated antigens and confirms that this group of neoplasms have immunophenotypic heterogeneity. the results of genotypic analyses used with immunophenotyping does not exclude that the tumor cells in these cases may be of true histiocytic origin despite the Ki‐1‐positive phenotype.

Characterization of a novel HHV-8-positive cell line reveals implications for the pathogenesis and cell cycle control of primary effusion lymphoma.

Primary effusion lymphoma (PEL) represents a peculiar type of B cell lymphoma which associates with HHV-8 infection and preferentially grows in liquid phase in the serous body cavities. In this report, we provide the detailed characterization of a newly established PEL cell line, termed CRO-AP/6. The cell line was obtained from the pleural effusion of a HIV-positive patient with PEL. Its derivation from the tumor clone was established by immunogenotypic analysis. Detailed phenotypic investigations defined that CRO-AP/6 reflects pre-terminally differentiated B cells expressing the CD138/syndecan-1 antigen. Karyotypic studies of CRO-AP/6 identified several chromosomal abnormalities, whereas genotypic studies ruled out the involvement of molecular lesions associated with other types of B cell lymphoma. Both CRO-AP/6 and the parental tumor sample harbored infection by HHV-8. Conversely, EBV infection was present in the parental tumor sample although not in CRO-AP/6, indicating that CRO-AP/6 originated from the selection of an EBV-negative tumor subclone. The pattern of viral (HHV-8 v-cyclin) and cellular (p27Kip1) regulators of cell cycle expressed by CRO-AP/6, together with the results of growth fraction analysis, point to abrogation of the physiological inverse relationship between proliferation and p27Kip1 expression. Also, both CRO-AP/6 and the parental tumor sample display biallelic inactivation of the DNA repair enzyme gene O6-methylguanine-DNA methyltransferase (MGMT) by promoter methylation. Overall, the CRO-AP/6 cell line may help understand cell cycle control of PEL cells, may clarify the relative contribution of HHV-8 and EBV to the disease growth and development and may facilitate the identification of recurrent cytogenetic abnormalities highlighting putative novel cancer related loci relevant to PEL.

Demonstration of S-100 protein distribution in human lymphoid tissues by the avidin-biotin complex immunostaining method.

Immunoreactivity for S-100 protein was investigated immunohistochemically in a series of 49 fixed and paraffin-embedded normal, reactive, and neoplastic human lymphoid tissue specimens. The avidin-biotin complex immunoperoxidase method was used, with overnight (12-hour) incubation with a commercially available antiserum to S-100 protein. In addition, cryostat sections were tested with DRC 1 monoclonal antibody to dendritic reticulum cells (DRCs) in three cases and with OKT6 antibody to interdigitating reticulum cells (IRCs) in nine cases. All tissues, including lymph nodes, tonsils, adenoid, spleens, appendices, thymuses, and tissues containing nodular reactive lymphoid infiltrates, demonstrated a consistent immune staining pattern. A striking network composed of dendritic processes that showed finely granular S-100 protein immunoreactivity was observed in most of the follicular germinal centers; a similar dendritic pattern was observed in the follicular centers when the corresponding frozen sections were immunostained with DRC 1. In the extrafollicular areas, the S-100-positive cells topographically and morphologically resembled the IRCs that were demonstrated by OKT6 antibody in the corresponding frozen sections. The results seem to indicate that cells topographically and morphologically similar to IRCs and DRCs in human lymphoid tissues from different sites share immunoreactivity for S-100 protein. The present study confirms the unexpected presence of S-100 protein in dendritic cells of follicular germinal centers by a simple and currently available method.

Non-Hodgkin's lymphoma in the elderly. I. Pathologic features at presentation

The pathologic findings of 118 patients aged 70 years or older with non‐Hodgkins lymphoma (NHL) are reported. These patients formed 27.2% of 433 consecutive cases of NHL seen in a single institution over a 5‐year period. Thirty‐one of 433 NHL cases were histologically not classified, whereas the remaining 402 could be classified according to the International Working Formulation (WF) of NHL for clinical usage. Immunophenotypic analyses were carried out in 112 NHL cases; of this group 28 were NHL in elderly patients. Of the 95 elderly NHL that could be classified in the histologic categories of the WF 28 cases were in the low‐grade, 41 in the intermediate‐grade, and 26 in the high‐grade categories. Eighty‐one cases had diffuse histologic types and 14 had follicular/nodular histologic types. Thirty‐five cases were of the G (diffuse large cell) + H (large cell, immunoblastic) categories. No significant differences in the prevalence of the different subtypes were observed among patients younger or older than 70 years. Immunohistologically, most NHL cases in the elderly expressed B‐cell phenotype. Sixty‐two NHL in the elderly were extranodal at presentation. The results of this study indicate that elderly patients form a relevant proportion of patients developing NHL and thereby present a very difficult management problem. The pathologic features of NHL in the elderly does not differ significantly from those of their younger counterparts, although an increase in diffuse versus follicular histologic patterns, and in extranodal versus nodal disease was observed with advancing age.

S-100 protein, fibronectin, and laminin immunostaining in lymphomas of follicular center cell origin

Forty‐nine paraffin‐embedded biopsy specimens of involved nodal and extranodal tissue (bone marrow, spleen, and liver) from 13 patients with follicular center cell lymphomas (FCCL) and 14 with small lymphocytic lymphomas (SLL), including 11 cases with chronic lymphocytic leukemia, were tested for Sg100 protein immunoreactivity. Analysis for fibronectin and laminin immunoreactivities was limited to the lymph node biopsy specimens. In FCCL, S‐100‐positive dendritic reticulum cells (DRCs) were found in 23 of the 26 tissue specimens examined, regardless of the involved sites and the growth pattern. Cases with completely or predominantly follicular pattern were usually associated with a spherical meshwork pattern of S‐100‐positive DRCs; in the FCCL specimens with a diffuse pattern (lymph nodes and bone marrow) as well as in the specimen areas with a minimally follicular tumor pattern, S‐100‐positive DRCs were consistently fewer in number and composed loosely aggregated nests. No S‐100‐positive DRCs were found in all the biopsy specimens in SLL. Concerning fibronectin and laminin immunostainings, results showed that no differences were present between areas of follicular and diffuse neoplastic growth and that the neoplastic growth of FCCL maintained for each antiserum the same distribution pattern as that seen in normal follicles. Analysis of the microenvironmental components as revealed with antisera used in the current study—particularly with anti‐S‐100 protein antiserum—appears to be a useful adjunct for the identification of FCCL in paraffin‐embedded biopsy specimens, especially in extranodal sites.

S-100 protein immunostaining in cells of dendritic morphology within reactive germinal centers by ABC immunoperoxidase method

The “dendritic” and the “interdigitating” (IRC) reticulum cells are commonly reported to have different topographical distribution in the human lymphoid tissue and some peculiar cytochemical and immunohistochemical features. These include the detection of S-100 protein by PAP (peroxidase anti-peroxidase) method only in IRC located in the thymus-dependent areas. In 15 reactive lymphoid tissue specimens (11 lymph nodes, 3 tonsils, and 1 adenoid) the presence of S-100 protein was tested by ABC (avidin-biotin complex) immunoperoxidase method. IRC were constantly positive. Other positive cells were located within the follicular germinal centers; these immunostained cells appeared as a striking network composed of dendritic-shaped processes displaying a finely granular positivity for S-100 protein. It is suggested that by using this very sensitive technique, S-100 protein can also be detected in intrafollicular cells of dendritic morphology.