Molecular-genetic analysis of ocular adnexal benign lymphoid hyperplasias by a two-step polymerase-chain-reaction

Clonal analysis of bilateral, recurrent, or systemically multifocal ocular adnexal lymphoma

The purpose of this study is to determine the same or different clonality between bilateral or recurrent lesions, or between or among ocular adnexal lesions and systemically multifocal lesions in 10 consecutive patients with ocular adnexal lymphoma : 8 had extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) and 2 had mantle cell lymphoma, observed from 1995 to 2008 at Okayama University Hospital. A discrete DNA fragment was generated by polymerase chain reaction amplification of the immunoglobulin heavy chain gene from all samples except for two samples of bilateral orbital mantle cell lymphoma lesions and one sample of the scalp skin MALT lymphoma lesion. The size of DNA fragments were the same between bilateral orbital or conjunctival lesions of 5 patients, between original and recurrent conjunctival lesions of one patient, between the orbital lesion and the oral cavity lesion in one patient, and among bilateral orbital lesions, buccal, rectum, and stomach lesions of one patient. Sequencing of the DNA fragments showed the same sequence between bilateral or recurrent or multifocal lesions in 8 patients except for one : the bilateral orbital lesions, rectum, and stomach lesions shared the same sequence while the buccal lesion had one nucleotide difference compared to the sequence shared by the other 4 lesions. In conclusion, bilateral, recurrent, or systemically multifocal lesions of ocular adnexal lymphoma shared the clonality between or among the lesions.

Clonal B cell populations in a minority of patients with Hashimoto's thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is a risk factor for thyroid lymphoma, and clonal B cell populations in HT support this link. The literature on B cell clonality in HT is controversial.

AIMS

To identify clonal B cell populations in HT and to assess their usefulness in differentiating HT from mucosa associated lymphoid tissue (MALT) lymphoma and predicting future development of lymphoma.

METHODS

DNA from formalin fixed, paraffin wax embedded blocks of thyroid specimens from 10 patients with HT and two thyroid MALT lymphomas was analysed for B cell clonality by seminested polymerase chain reaction (PCR) using FRIII/LJH and FRIII/VLJH primers to amplify the IgH gene VDJ region. In one case, PCR products were sequenced. Immunohistochemistry was performed by labelled streptavidin-biotin technique using antibodies to: CD45, CD45RO, CD3, CD20, and cytokeratin.

RESULTS

The histopathological and clinical findings were characteristic of HT. Clonal bands were seen in three and a polyclonal smear pattern was seen in seven cases. The clonal bands in HT were associated with a background smear, and could not be reproduced from other blocks from the same case or from deeper sections of the same block. The clonal bands in thyroid lymphomas were not associated with a background smear and were reproducible. None of the patients with clonal B cells has developed malignant lymphoma during a follow up of 10-13 years.

CONCLUSIONS

B cell clonal bands in HT have different features from those in lymphoma (non-pure and non-reproducible) and do not predict future development of lymphoma.

Clinical, histopathological, and immunogenetic analysis of ocular adnexal lymphoproliferative disorders: characterization of malt lymphoma and reactive lymphoid hyperplasia

Malignant lymphomas and reactive lymphoid hyperplasia (RLH) in the ocular adnexa are sometimes difficult to differentiate morphologically and have often been categorized together as a lymphoproliferative disorder. Immunogenotypic characters of these diseases have not yet been well clarified. This study included 76 cases of ocular adnexal lymphoproliferative disorders. These consisted of 52 cases of malignant lymphoma (43 primary and 9 secondary), 22 of RLH, and 2 borderline cases. There were slightly more male than female subjects. Diagnoses were based on morphology and immunophenotypic characteristics. Clonalities were detected by means of polymerase chain reaction (PCR), and immunoglobulin heavy-chain variable region (VH) genes were sequenced in 10 cases of mucosa-associated lymphoid tissue (MALT) lymphoma. MALT lymphoma constituted 86% (37 cases) of the primary lymphomas. MALT lymphomas were more indolent, more rarely disseminated, and had a lower death rate than the other primary lymphomas. Two patients exhibited coexistence of MALT and diffuse large B-cell lymphoma. The average age of patients with RLH was 5.5 years younger than that of those with MALT lymphoma. One of the cases of RLH later progressed to malignant lymphoma. B-cell clonality was detected by PCR in 57%, 55%, and 0% of primary lymphomas, MALT lymphomas and RLHs, respectively. Sequencing of VH genes revealed that the VH3 family was the most commonly expressed germline VH family (70%) and that DP-63, DP-54 and DP-47 genes were frequently found in the MALT lymphomas examined. PCR analysis was useful for differentiation between MALT lymphoma and RLH. Sequence analysis of VH genes showed that an autoimmune mechanism may be involved in the lymphomagenesis of ocular adnexal MALT lymphoma.

Conjunctival AL amyloidosis associated with a low-grade B-cell lymphoma

A rare case of localized amyloidosis associated with a low-grade B-cell lymphoma involving the conjunctiva is described. Although infiltrating small lymphocytes and plasma cells showed little cytological atypia, molecular genetic examination revealed a prominent B-cell clonal immunoglobulin heavy chain (IgH) gene rearrangement in the tumor tissue. Immunoelectronmicroscopic examination showed immunoglobulin lambda light chain specificity in the amyloid deposit and Russell bodies in the surrounding plasma cells. We concluded that the immunoglobulin lambda light chain, produced by the tumor's differentiated plasma cells, is the precursor protein of the localized amyloidosis found in this case.

PCR analysis of IgH and BCL2 gene rearrangement in the diagnosis of follicular lymphoma in lymph node fine-needle aspiration. A critical appraisal

In order to improve the cytomorphologic diagnosis of malignant lymphoma on lymph node fine-needle aspiration (FNA), and to make a confident discrimination between low-grade follicular non-Hodgkin's lymphoma (NHL) and lymphoid hyperplasia, polymerase chain reaction (PCR) analysis was performed of the Ig CDR3 region and BCL2 breakpoint region in 25 nonselected cases of malignant lymphoma (17 NHL and 8 Hodgkin's disease [HD]) with histologic control, and 22 cases of lymph nodal hyperplasia with histologic and/or clinical control. Among lymphomas, IgH monoclonality was detected in 7 (77%) of 9 NHLs and BCL2 rearrangement in 3 (17.6%) of 17 NHLs, all of which were follicular centroblastic-centrocytic (FCBCC). Three BCL2/JH negative FCBCC cases were monoclonal for CDR3. Neither IgH monoclonality nor BCL2 rearrangement were found in HD. Among cytologically diagnosed lymphoid hyperplasias, one IgH polyclonal case was considered false-negative, being histologically diagnosed as lymphoplasmacytic NHL on the subsequent excisional biopsy. Another 4 cases (2 BCL2 rearranged and 2 monoclonal for IgH) were considered false-positive on the basis of histologic features or clinical control. These data indicate that the combined PCR analysis of IgH and BCL2 rearrangements can confirm a cytologic diagnosis of lymphoma in FNAs while, due to the occurrence of both false-positive and false-negative results, it is of limited value in the distinction between follicular lymphoma and lymphoid hyperplasia without morphologic or clinical support.

B-cell gene rearrangement in benign and malignant lymphoid proliferations of mucosa-associated lymphoid tissue and lymph nodes

The polymerase chain reaction (PCR) with polyacrylamide gel electrophoresis was used to study patterns of immunoglobulin heavy chain (IgH) gene rearrangement (GR) in formalin-fixed, paraffin-embedded specimens of lymphomas and reactive conditions of mucosa-associated lymphoid tissue (MALT) and lymph node. DNA amplification was performed directly on sections obtained from paraffin blocks. Five patterns of PCR products were observed: a single band, two or more discrete bands, smearing, a single band overlying a smear, and two or more bands over a smear. A pure polyclonal pattern (smear) was observed in all of the reactive lymph nodes but in only 15% of cases of Helicobacter pylori (HP) gastritis with lymphoid hyperplasia, 25% of cases of HP gastritis without lymphoid hyperplasia, and 37% of colonic specimens of various types. Patterns consisting of multiple bands with or without background smearing were common in gastritis, colitis, and gastric lymphomas. Single bands or dominant bands were present in all lymph node and salivary gland lymphomas, 12 of 14 cases of gastric lymphoma, and 17 of 20 cases of HP gastritis with lymphoid hyperplasia. These bands were reproducible in deeper sections from the same paraffin block or similar areas sampled in different blocks in all of the lymph node and salivary gland lymphomas, 11 of 12 gastric lymphomas, but only 1 of 17 cases of HP gastritis with lymphoid hyperplasia. Bands were also found in 3 of 20 cases of HP gastritis without lymphoid hyperplasia and 17 of 38 colonic specimens, but these were not reproducible. The complexity of patterns of IgH GR in acquired MALT compared with lymph nodes may be the result of a relative paucity of B-cell clones or preferential proliferation of B-cell clones with a limited area of distribution.

Epstein-Barr-virus-associated medullary carcinomas with lymphoid infiltration of the stomach

The association of Epstein-Barr virus (EBV) with gastric medullary carcinoma with lymphoid infiltration (GMCL) was investigated. The presence of GMCL exhibited a 2/1 male-to-female ratio and a 1/2 early-to-advanced cancer ratio, predominantly located in the cardia and corpus of the stomach (90%). The presence of EBV DNA could be proven in 28 out of 30 GMCL cases (93%) by the polymerase chain reaction method, and in 27 cases (90%) latent infection of EBV strictly limited to cancer cells was identified by in situ hybridization with RNA using an EBV-associated small RNAs (EBERs) probe. No histopathological difference was noted between EBERs-positive and -negative groups. Monoclonal EBV infection, identified by the length of lymphocyte-determined membrane antigen variable tandem repeats, was suggested in 19 out of 27 EBERs-positive cases (70.3%). However, only one case showed a positive reaction for anti-(latent membrane protein)-1 antibody, and none of the EBERs-positive cases bound anti-EBNA-2 antibodies, the respective antigens being considered oncoproteins directly linked with EBV-related B cell lymphomagenesis. In conclusion, while EBV is clearly present at extremely high incidence in GMCL, having characteristics biological features, a role for EBV in tumorigenesis of such lesions remains uncertain.