Florid CD4+, CD56+ T-cell infiltrate associated with Herpes simplex infection simulating nasal NK-/T-cell lymphoma.

We report a case of Herpes simplex virus (HSV) infection of the nasopharynx associated with a dense CD4+, CD56+ T-cell infiltrate that simulated lymphoma on clinical, histologic, and immunophenotypic grounds. Histologic examination showed a tumorlike lymphoid infiltrate with extensive necrosis. Multinucleated giant cells with "ground-glass" nuclei characteristic of HSV were observed in necrotic areas but were not prominent. Immunohistochemical studies of the lymphoid infiltrate revealed a predominance of T cells, positive for CD3, CD4, CD5, and CD56. Immunohistochemical staining with HSV antibody was focally positive in the multinucleated giant cells. Molecular studies using PCR and Southern blot were positive for HSV Type II. PCR studies for T-cell receptor gamma and immunoglobulin heavy chain gene rearrangements showed no evidence of a clonal population. In situ hybridization studies for Epstein-Barr virus (EBV) were negative. The clinical presentation of a large fungating mass, the extent of the lymphoid infiltrate, and the expression of CD56 all raised the possibility of a nasal NK/T cell lymphoma. However, the presence of HSV, lack of angioinvasion and angiodestruction, absence of EBV, and polyclonal T-cell nature of the infiltrate argued against this diagnosis. Although prior studies have not fully characterized the immunophenotypic features of the lymphocyte response to HSV in infected tissues, we postulate that the CD56+, CD4+ T-cell reaction represents a florid antiviral immune response.     

Discordant expression of antigens between intraepidermal and intradermal T cells in mycosis fungoides.

Using immunohistochemical methods, the authors studied the expression of pan-T- and majority-T-cell antigens (CD5, CD2, CD3, TCR-beta, CD7) and T-cell subset antigens (CD4, CD8) in cutaneous T cells in mycosis fungoides (MF) (177 biopsies from 124 patients) and a variety of inflammatory lesions (45 biopsies from 45 patients). The authors detected the absence of pan-T- or majority-T-cell antigens, or of both T-cell subset antigens, from T cells in the epidermis but not the dermis in 15 MF biopsies (8%) from 11 MF patients (9%), but in none of the inflammatory skin lesions. The opposite picture, characterized by lack of antigen expression by the dermal T cells only, was not seen in any of the MF or inflammatory lesions. The absence of antigen expression by epidermal but not dermal T cells, which the authors have termed antigen discordance, was most prevalent for CD5, CD7, and TCR-beta, each being discordant in 6% to 7% of MF cases or patients tested. Among the MF biopsies showing antigen discordance, 14 of 15 biospies (93%) from 10 of 11 patients (91%) were discordant for two or more antigens. Antigen discordance was not an artifact of treatment, because none of the patients showing discordance was receiving treatment at the time of their initial discordant biopsy. The discordance was the only immunophenotypic abnormality detected in 8 of 15 (53%) of the discordant MF biopsies. Thus, this antigen discordance was an important diagnostic feature that allowed the immunophenotypic distinction of MF from a variety of inflammatory skin lesions.     

Expression of monoclonal antibody HML-1-defined alpha E beta 7 integrin in cutaneous T cell lymphoma.

Considering that integrins may play a major role in the localization in distinct biological features as well as in the dissemination of several types of lymphomas, we studied the expression of the monoclonal antibody HML-1-defined alpha E beta 7 integrin (CD103) in the clinically and histologically determined stages of 53 mycosis fungoides (MF) skin biopsies and in 16 affected lymph nodes. Immunoperoxidase staining revealed HML-1 immunoreactivity with T cells in the early stages of disease (patch and plaque stage MF). HML-1 expression was more pronounced on infiltrating epidermal than on dermal T cells. In contrast to early stages, tumor stage MF and lymph nodes affected in the course of cutaneous T cell lymphoma were HML-1 negative. We found a strong association between HML-1 expression, epidermotropism of infiltrating T cells, and the stage of disease. We provide evidence that: 1) the loss of the HML-1 antigen on T cells in MF is a marker of poor prognosis and 2) because the HML-1 antigen is selectively expressed on T lymphocytes of epithelial sites such as gut and skin, our results are compatible with the view that alpha E beta 7 integrins perform homing receptor functions for epitheliotropic T cells.     

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma: a clonal T-cell lymphoproliferative disorder with indolent behavior.

Primary cutaneous CD4-positive small/medium-sized pleomorphic T-cell lymphoma, a provisional entity in the 2005 WHO-EORTC classification for cutaneous lymphomas, is not well characterized. Fifteen cases meeting the definition of this entity were identified. Fourteen represented solitary lesions on the head/neck (n=9), upper extremity (n=4), or trunk (n=1). One patient presented with multiple lesions on the trunk and extremities. Histologically, the infiltrate showed a nodular pattern in the dermis and subcutis without epidermotropism, and had a polymorphous composition with a predominance of small to medium-sized CD4-positive T cells. Most cases showed normal T-cell antigen expression; diminished/absent expression of CD7 was seen in three cases and CD2 expression was absent in one case. All cases showed a notable reactive infiltrate including frequent B cells, plasma cells, and histiocytes. Clonal TCR gene rearrangements were detected in each case. No clonal Ig gene rearrangements were detected. Out of the 11 patients with follow-up, none showed systemic disease. The majority resolved without relapse, one without treatment, four with excision, and four with radiation therapy. One patient developed local recurrence. The patient with multiple lesions had disease progression despite chemotherapy and stem cell transplant. These cases highlight the polymorphous histology and prominent reactive B-cell component of this entity. Diagnosis requires molecular genetic analysis, as prominent cytologic atypia and immunophenotypic aberrancy are rare. The differential diagnosis includes reactive lymphoid hyperplasia, mycosis fungoides and cutaneous B-cell lymphomas. In patients with isolated cutaneous lesions, the indolent behavior of this rare T-cell neoplasm should be recognized to avoid unnecessary treatment.     

Identification of altered MicroRNA expression in canine lymphoid cell lines and cases of B- and T-Cell lymphomas

Canine lymphoma is a common spontaneous tumor with many similarities to human lymphoma, and thus has potential to be an important animal model of lymphomagenesis. This study determined that microRNA (miRNA) expression in canine tumors can be assessed using a commercially available human cancer miRNA qPCR array. miRNA expression in six different canine lymphoid cell lines and in naturally occurring canine B- and T-cell lymphomas was compared using RNA harvested from normal canine peripheral blood mononuclear cells (PBMC) and normal lymph nodes (LN) as controls. We found that false discovery rate (FDR) correction for multiple testing after quantile normalization controlled for variation across arrays and that they were the best methods for normalization and statistical analysis. Increases in miRNAs known to upregulate oncogenes (miR19a+b, miR17-5p) and decreased expression of miRNAs with tumor suppressor functions (miR-203, miR-218, and miR-181a) also seen in human lymphoid malignancies were observed. However, there were few similarities between canine groups. The results of this study indicate that the use of both PBMC and LN cells as controls provides different, but potentially equally important targets for further analysis. Our findings of miRNA dysregulation in canine lymphoid cell lines and clinical cases of lymphoma emphasize the potential of canine lymphoma as an important spontaneous, large animal model of human B- and T-cell lymphomas.     

Combined folliculotropic/syringotropic cutaneous T-cell lymphoma without epidermal involvement: report of 2 cases and pathogenic implications

Exclusive involvement of skin appendages in cutaneous T-cell lymphoma (CTCL) is rare, poses significant problems in diagnosis, and may provide insight into mechanisms of T-cell epitheliotropism. We report 2 cases of combined adnexal (folliculotropic/syringotropic) CTCL in which lesions developed only in chronically sun-damaged skin. Although the epidermal layer in both cases was devoid histologically of significant epidermotropism, immunohistochemistry and polymerase chain reaction analyses of deeper samples that included involved adnexae confirmed aberrant antigen expression (dominant CD4 populations with apparent loss of CD7 and/or CD5) and T cell clonality, respectively. It is diagnostically important to recognize adnexal CTCL as a disorder that may be clinically and histologically protean. Additionally, its occurrence in sun-damaged skin in some patients may provide insight into mechanisms of selective epitheliotropism by malignant T cells.     

DISTINCTIVE ADHESION PATHWAYS ARE INVOLVED IN EPITHELIOTROPIC PROCESSES AT DIFFERENT SITES

Intraepithelial migration of lymphoid cells (epitheliotropism) is a biological process that can be observed under various physiological and pathological conditions. Recently, epitheliotropism was proposed to be a multi-step process, involving interactions of lymphoid cells with both epithelial basement membrane (EBM) and epithelial cells. In the present study we analysed by immunohistochemistry the adhesion mechanisms that are potentially involved in epitheliotropism of lymphoid cells in various disorders, such as tonsillar hyperplasia, coeliac disease, malignant lymphomas of mucosa-associated lymphoid tissue (MALTomas), and mycosis fungoides (MF). The combinations of adhesion molecules expressed on the participating lymphoid and epithelial cells varied among these disorders. These findings suggest the adhesion pathways utilized in epitheliotropism may be associated with the nature of the lymphoid cell (reactive or neoplastic/B or T) and/or the site of the epithelium involved. In some cases the specificity of the process was determined by the adhesion mechanism involved in the lymphocyte–EBM interaction, as in the case of α3β1 integrin/laminin-5 in MF, and in others by the adhesion mechanisms involved in the interaction between lymphoid and epithelial cells, such as α4 integrin/VCAM-1 in tonsillar hyperplasia and αEβ7/E-cadherin in coeliac disease.     

Primary cardiac cytotoxic T-cell lymphoma presenting with neurological deficits: a case report.

BACKGROUND: Primary cardiac lymphoma is extremely rare in immunocompetent patients. Clinical manifestations vary, and, most often, diagnosis is not made until autopsy. The majority of reported primary cardiac lymphoma cases have been of B-cell origin, while T-cell cardiac lymphomas have been extremely rare. Occasionally, lymphomas and other systemic malignancies clinically present as paraneoplastic neurological syndromes. METHODS: We report a unique case of primary cardiac peripheral T-cell lymphoma of cytotoxic phenotype, clinically presenting with neurological features of external ophthalmoplegia and lower cranial nerve paresis mimicking mitochondrial cytopathy, that was recognized at autopsy. Brain and thoracoabdominal viscera retrieved at autopsy were fixed in 10% buffered formalin and processed for paraffin embedding. In addition to routine histology, immunohistochemistry for immunophenotypic characterization of lymphoma cells was performed. Fresh skeletal muscle was processed for cryosectioning and histochemical staining. RESULTS: On gross examination, the heart showed multiple circumscribed, whitish nodules on both sides. Histological examination of these nodules revealed lymphomatous deposits-cells expressing CD45, CD2, CD3, CD5, CD7, CD8, perforin, and granzyme B. Histological sections from the brain showed foci of demyelination and patchy perivascular lymphoid cell aggregates in leptomeninges and within the parenchyma. These lymphoid cells expressed CD2, CD3, and CD5, with the T cells being predominantly CD4 (CD4:CD8>2), which was unlike the CD8-predominant lymphomatous infiltrate in the heart. Hence, these lymphoid cells in the brain, rather than disseminated lymphoma cells, were considered to be related to the demyelinating process. There was no evidence of lymphomatous deposits in the rest of the viscera examined. CONCLUSION: A diagnosis of primary cardiac peripheral T-cell lymphoma of cytotoxic phenotype clinically manifesting as paraneoplastic demyelinating lesions in the brain was described.     

The usefulness of flow cytometric CD10 detection in the differential diagnosis of peripheral T-cell lymphomas

We studied the histologic and multiparameter flow cytometry (MFC) features of 12 cases of angioimmunoblastic T-cell lymphoma (AITL), 13 of mature T-cell lymphoma, and 25 control cases of reactive lymphoid hyperplasia to evaluate the role of CD10 in the differential diagnosis of peripheral T-cell lymphomas (PTCLs). A characteristic immunophenotypic profile (CD2+/CD4+) with recurrent phenotypic aberrancies (eg, CD3 and CD7 loss) was identified in most AITL cases; MFC documented CD10 coexpression on T cells in 10 (83%). Mature T-cell lymphoma showed a more heterogeneous altered immunophenotypic pattern, and 2 cases of PTCL, unspecified, had clear evidence of aberrant CD10 expression on T cells. A small physiologic CD3+/CD4+/CD10+ T-cell population was detected by MFC in all control cases tested (range, 0.28%-4.71%), suggesting that a normal subset of peripheral CD10+ T cells exists. CD10 was a highly sensitive but incompletely specific phenotypic marker for diagnosing AITL; the differential diagnosis of PTCL, unspecified, must be related with traditional histologic features. A small number of CD10+ T cells in reactive lymph nodes suggests that this subpopulation may be the normal counterpart of neoplastic T cells in AITL. The biologic role of CD10+ T cells should be studied further.     

Density of neoplastic lymphoid infiltrate,CD8+ T cells,and CD1a+ dendritic cells in mycosis fungoides

BACKGROUND/AIMS: CD8+ T cells and epidermal/dermal dendritic cells expressing CD1a are found among neoplastic CD4+ T cells in mycosis fungoides (MF) lesions. This study analysed the relation of CD8+ tumour infiltrating lymphocytes (TILs), CD1a+ epidermal Langerhan's cells (LCs), and dermal dendritic cells (DDCs) to clinicopathological parameters in 46 MF cases. METHODS: Pretreatment diagnostic biopsy specimens of 46 MF cases were submitted to histological analysis and immunohistochemistry. Four histological grades were defined based on the density of the neoplastic infiltrate: grade 1 (mild superficial perivascular infiltrate), grade 2 (moderate superficial perivascular infiltrate with some tendency to confluence), grade 3 (pronounced superficial band-like infiltrate), and grade 4 (deep nodular infiltrate). Epidermotropism was scored as low, moderate, or high. Numbers of CD8+ T cells and of dermal and epidermal CD1a+ cells were scored as 1 (low), 2 (moderate), and 3 (high). Correlations between these parameters and clinical data (age, sex, clinical type of lesions, stage, response to treatment, and recurrence) were analysed by the chi(2) test. RESULTS: Numbers of TILs and DDCs were associated with subepidermal infiltrates, being lower in less dense infiltrates, whereas there was no association between epidermal CD1a+ cells and the analysed parameters. Complete remission in treated patients was related to subepidermal infiltrates but not to TILs, LCs, or DDCs. CONCLUSIONS: These results support the notion that CD8+ cells and dermal CD1a+ cells are active against tumour cells. MF with low numbers of TILs could represent an early stage of the disease, before TILs are activated against tumour specific antigens.     

Morphologic and immunophenotypic analysis of angioimmunoblastic T-cell lymphoma: Emphasis on phenotypic aberrancies for early diagnosis

The morphologic features and immunophenotype of diagnostic nodal and bone marrow biopsy specimens were reviewed in 29 well-established cases of angioimmunoblastic T-cell lymphoma (AILT). All cases showed a characteristic polymorphous lymphoid and inflammatory cell infiltrate along with stromal-vascular changes. Perivascular aggregation or clustering of neoplastic clear cells was seen in only 41% of cases. Unique architectural changes, including extranodal extension (83%), follicular dendritic cell proliferation (93%), and a distinctly marginalized distribution of residual B cells (67%) were observed. Subsets of T cells with immunophenotypic abnormalities (CD10 coexpression or loss of pan-T-cell antigens CD3 and CD7) were identified in a majority of cases (96%). Significantly, these morphologic and phenotypic features were seen irrespective of the presence of an overt lymphomatous pattern. Bone marrow involvement was present in 90% of patients with available biopsy specimens. Our results indicate that unique morphologic alterations and subsets of phenotypically aberrant T cells are present consistently in nearly all cases of AILT, including morphologically less definitive biopsy specimens.     

The CD45 isoform B220 identifies select subsets of human B cells and B-cell lymphoproliferative disorders

The B220 isoform of CD45, a pan B-cell marker in mice, is expressed by only a subset of human B cells that do not express the memory B-cell marker CD27, suggesting that it is a differentiation-specific isoform of CD45. We examined normal human peripheral blood B cells, secondary lymphoid tissue, and a range of human B-cell lymphoproliferative disorders for the expression of B220 by flow cytometric immunophenotyping and immunohistochemical staining. We found that a subset of human B cells in peripheral blood is positive for B220 by flow cytometric immunophenotypic analysis. In reactive lymphoid tissues, B220 is expressed by B cells occupying the mantle zones and by a subpopulation of germinal center cells, but, in contrast, marginal zone B cells in the spleen do not express B220. Of 94 cases of B-cell lymphoproliferative disorders, 33 (35%) were positive for B220 by flow cytometric immunophenotypic analysis, including most cases of marginal zone lymphoma, follicular lymphoma, and lymphoplasmacytic lymphoma. In contrast, all cases of precursor B lymphoblastic leukemia/lymphoma, mantle cell lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma were negative for B220. Immunohistochemical staining for B220 correlated with flow cytometric analysis for all cases studied by both methods. Our data demonstrate that B220 is expressed in a select subset of normal, reactive B cells in a pattern that is consistent with a marker of naive B cells. However, this restricted expression pattern is not seen in B-cell lymphoproliferative disorders. Discordance between the B220 expression patterns of normal mantle and marginal zone B cells and their respective neoplastic counterparts may aid in the distinction between normal and neoplastic proliferations at these anatomical sites.     

Immunohistochemical characterization of a B-cell signet ring cell lymphoma. Report of a case

Signet ring cell lymphoma is a non-Hodgkin's lymphoma, characterized by neoplastic lymphoid signet ring cells very similar to epithelial mucin producing cells. We describe here a case of signet ring cell lymphoma in which the immunophenotypic markers of signet ring cells parallel those of plasma cells, being intensively T10+ (CD 38), weakly HLA-DR+, and To15 (CD 22) and T200 (CD 45) negative. The morphologic and immunohistochemical features of the case and the main differential diagnosis are preceded by a review of the literature.     

Immunohistological analysis of immune cells in blistering skin lesions

BACKGROUND: Bullous skin lesions are characterised by the presence of intraepidermal or subepidermal bullae. Although inflammatory cell infiltrate is a constant feature in these lesions, their immunophenotypic characterisation is still incomplete. AIM: To determine whether the development of bullous skin diseases is associated with changes in the inflammatory cell infiltrate. Materials and methods: 34 cases representing lesions with both intraepidermal and subepidermal bullae were examined using immunoperoxidase staining methods and antibodies targeting antigens for histiocytes (CD68), B cells (CD20+), T cells (CD3+), T cells with cytotoxic potential (T cell intracellular associated antigen, TIA1+) and activity (granzyme B, GRB+). The adjacent normal skin (lesions) and an additional five cases of normal skin were also examined (controls). RESULTS: The transition from normal skin to lesional skin (lesions with intraepidermal and subepidermal bullae) was associated with a significant increase (p< or =0.05) in the density of total inflammatory cell infiltrate, CD68+ cells, CD3+ T lymphocytes, CD20+ B lymphocytes, TIA1+ -resting cytotoxic T cells and GRB+ T cells with cytotoxic activity. CONCLUSIONS: The increase in inflammatory cell infiltrate during the transition from normal to lesional skin may reflect the presence of an increased antigenicity of the lesional cells or a response to some basement membrane components. CD68+ and CD3+ cells, especially the resting cytotoxic ones, achieved numerical dominance in these lesions. Cell-mediated immunity seems to have critical role in the development of these lesions.     

Comparative immunophenotypic characterization of human and monkey permanent lymphoid culture cells

The aim of the study was to define the comparative immunophenotypic characteristics ofwidely spread lymphoid cell cultures, derived from Burkett's lymphoma named as Raji and P3HR-1 in comparison with analogous monkey cultures. It has been shown that P3HR-1 culture consists of similar type cells - activated B-lymphocytes CD23 with k phenotype, which demonstrates its monoclonality. Raji culture includes cells with markers of immature B-lymphocytes CD10 and CD24, as well as elements expressing CD10 antigens. T-cell markers were found in none of the cultures. In contrast to human cells, monkey lymphoid culture expressed both B- and T-cell markers. Moreover, in one of them, obtained from a green monkey, T-cells of suppressor type (CD8) prevailed. The immunophenotypic characteristics of primate lymphoid cell cultures, revealed by the study, are of great importance for their proper application to medical and biological studies.     

CD30-positive T-cell lymphoproliferative disorder of the oral mucosa--an indolent lesion: report of 4 cases

Four cases of CD30-positive T-cell lymphoproliferative disorder (CD30+ LPD) of the oral mucosa are described. This article aims to draw attention to this entity and to emphasize its usual benign clinical behavior despite its resemblance to T-cell lymphoma. All the patients were adults. Three of the lesions were on the dorsal surface of the tongue and 1 affected the buccal mucosa. All biopsies showed a dense lymphoid infiltrate composed of CD30+ atypical T cells with a polymorphous infiltrate in the background, which included eosinophils. In 1 case, monoclonal T-cell expansion was detected by molecular techniques. Three cases tested for Epstein-Barr virus were all negative. It is concluded that primary CD30+ T-cell LPD of the oral mucosa can be regarded as the oral counterpart of cutaneous CD30+ LPD such as lymphomatoid papulosis or anaplastic large cell lymphoma. Recognition of the condition is important to avoid overtreatment.     

血管免疫母细胞性T细胞淋巴瘤的形态及免疫表型研究

目的 研究血管免疫母细胞性T细胞淋巴瘤(AITL)形态学特点、特异性标志物,并探讨AITL中滤泡树突状细胞网的增生状况及其起源.方法 对29例AITL行bcl-6、CD10、CXCL13、CD21染色(EliVision法)及bcl-6/CD3、CD10/CD21及CD10/CD20双重染色,并选取外周T细胞淋巴瘤,非特殊类型(PTL-U);结外NK/T细胞淋巴瘤,鼻型;间变性大细胞淋巴瘤(ALCL);肠病性T细胞淋巴瘤(ETTL);皮下脂膜炎性T细胞淋巴瘤及淋巴结反应性增生作为对照.结果 (1)22例(75.9%)AITL表达CD10,对照组除1例PTL-U外均阴性;24例(82.8%)AITL表达CXCL13,所有PTL-u均阴性;而AITL中bcl-6的表达情况和PTL-u及反应性增生病例有一定程度的交叉.(2)29例AITL显示特征性的CD21阳性滤泡树突状细胞网增生,4例具有明显生发中心的病例,2例显示增生的滤泡树突状细胞网覆盖并超过生发中心.结论 AITL具有典型的形态学变化,CD10和CXCL13是AITL特异性标志物,而bcl-6不具有特异性;AITL中增生的滤泡树突状细胞网可能部分起源于生发中心.     

间变性大细胞淋巴瘤形态学及免疫表型观察

目的：探讨间变性大细胞淋巴瘤（ALCL）的形态学和免疫表型特征。方法：对6例ALCL和2例弥温性大B细胞淋巴瘤（DLBCL）进行形态学和免疫组织化学染色（ABC法）观察。结果：6例ALCL中，普通型2例、淋巴组织细胞型2例、ALK－变型2例，均可见单型性或多形性的标志性大细胞。普通型和ALK－变型大细胞沿淋巴窦内生长，而淋巴组织细胞型大细胞则呈散在分布；2例DLBCL形态上颇似ALCL；6例ALCL均为T细胞，CD30＋，儿童患者共同表达ALK＋和EMA＋，年长者则ALK－和EMA－。2例DLBCL均为B细胞，ALK＋、CD30－和EMA－。结论：不论何型ALCL，均可见CD30＋的标志性大细胞，淋巴窦内生长多见于普通型和ALK－变型。ALCK均为T细胞，儿童常有ALK和EMA共同表达，年长者则ALK和EMA－。DLBCL的免疫表型不同于ALCL。