Leu-22 (L60). A more sensitive marker than UCHL1 for peripheral T-cell lymphomas, particularly large-cell types

Anaplastic large cell lymphoma: twenty-five years of discovery

CONTEXT

The year 2010 commemorates the 25th year since the seminal publication by Karl Lennert and Harald Stein and others in Kiel, West Germany, describing an unusual large cell lymphoma now known as anaplastic large cell lymphoma (ALCL). Investigators at many universities and hospitals worldwide have contributed to our current in-depth understanding of this unique peripheral T-cell lymphoma, which in its systemic form, principally occurs in children and young adults.

OBJECTIVE

To summarize our current knowledge of the clinical and pathologic features of systemic and primary cutaneous ALCL. Particular emphasis is given to the biology and pathogenesis of ALCL.

DATA SOURCES

Search of the medical literature (Ovid MEDLINE In-Process & Other Non-Indexed Citations and Ovid MEDLINE: 1950 to Present [National Library of Medicine]) and more than 20 years of diagnostic experience were used as the source of data for review.

CONCLUSIONS

Based on immunostaining for activation antigen CD30 and the presence of dysregulation of the anaplastic lymphoma kinase gene (2p23), the diagnosis of ALCL has become relatively straightforward for most patients. Major strides have been made during the last decade in our understanding of the complex pathogenesis of ALCL. Constitutive NPM-ALK signaling has been shown to drive oncogenesis via an intricate network of redundant and interacting pathways that regulate cell proliferation, cell fate, and cytoskeletal modeling. Nevertheless, pathomechanistic, therapeutic, and diagnostic challenges remain that should be resolved as we embark on the next generation of discovery.

T-cell lymphoma presenting as painful ophthalmoplegia

Purpose

To present a case of peripheral T-cell lymphoma presenting as painful ophthalmoplegia.

Methods

A 61-year-old woman presented with a 2-week history of headache and eyeball pain. Examination showed mild exophthalmos, complete ophthalmoplegia, and ptosis of the left eye. Under the impression of nonspecific orbital inflammation, she was treated with oral prednisone with initial response. Two months later, she revisited the clinic with exacerbated symptoms. Anterior orbitotomy and incisional biopsy was performed for the inferior rectus muscle lesion.

Results

Histopathologic examination revealed an infiltrate of atypical lymphoid cells between degenerative muscle bundles. It was consistent with peripheral T-cell lymphoma. A metastatic workup was performed without any evidence of extraorbital tumor. The patient was recommended to be treated with chemotherapy, however, refused to take the treatment. The patient died of progression of the disease in a month.

Conclusions

T-cell lymphoma in the orbit can present as painful ophthalmoplegia and take a rapid clinical course. The disease should be regarded as one of the differential diagnosis for painful ophthalmoplegia refractory to corticosteroid therapy.

CD4+CD7- leukemic T cells from patients with Sézary syndrome are protected from galectin-1-triggered T cell death

In early stages of cutaneous T cell lymphoma (Sézary syndrome) both CD4+CD7- and CD4+CD7+ T cells clonally expand whereas in late stages of the disease CD7- cells are predominant in number, giving rise to the question whether CD7- T cells have a survival advantage in the skin. Galectin-1, a cell-bound lectin, was recently reported to trigger apoptosis in activated CD7+ T cells. Here, we demonstrate that in contrast to activated CD7(+) T cells, quiescent and activated CD69+ CD7- T cells from healthy donors and from Sézary patients are resistant to galectin-1-mediated cell death. CD7- T cells are apoptosis-resistant even during coculture with IFN-gamma-stimulated endothelial cells that constitutively express galectin-1 in high amounts. These data imply that resistance of CD7- T cells to galectin-1-induced apoptosis may contribute to the accumulation of CD7- Sézary T cells during progression of the disease.

Identification of tumours with the CD43 only phenotype during the investigation of suspected lymphoma: a heterogeneous group not necessarily of T cell origin

AIMS

CD43 is usually employed as a T cell marker in the immunophenotypic work-up of suspected cases of non-Hodgkin's lymphoma (NHL). In this setting, tumours expressing CD43 in the absence of other T or B cell markers (CD43 only phenotype) are rare. We present four cases with this aberrant phenotype seen at our institution.

METHODS

The CD43 only phenotype was defined as expression of CD43 in the absence of expression of B cell markers CD20 and CD79a, and T cell markers CD3 and CD5, on initial immunohistochemistry performed on biopsies of suspected NHL. Combinations of further immunohistochemistry, flow cytometry, cytogenetic analysis and molecular studies were used to enable further diagnosis and lineage assignment.

RESULTS

The four cases were subsequently diagnosed as: one case of extramedullary acute myeloid leukaemia, one case of null cell anaplastic large-cell lymphoma, and two cases of extranodal diffuse large B cell lymphoma. None were demonstrated to be of T cell origin.

CONCLUSIONS

Our series further confirms the lack of specificity of CD43 expression for T cell lineage. Documentation of the CD43 only phenotype in suspected cases of NHL therefore requires further investigation to both correctly diagnose and clarify lineage of these tumours.

Paraffin immunohistochemistry as an adjunct to hematopathology

In the past two decades, there have been a number of dramatic advances in immunology that have subsequently affected immunohistochemistry. These have had a substantial impact on all phases of laboratory medicine, especially surgical pathology. Many hospital laboratories use immunohistochemical analysis on paraffin-embedded tissue sections as routinely as other special histochemical techniques. Hematopathology, in particular, has become increasingly reliant on the immunohistochemical antibody technique. This method aids in the identification of lineage-associated or lineage-restricted antigens in hematolymphoid neoplasms. The demonstration of kappa or lambda light-chain restriction is a good indicator of monoclonality in B-cell processes, aiding in the distinction between benign reactive hyperplasia and malignant lymphoma. Increasing numbers of antibodies that react to cluster differentiation cell surface antigens have become available for use in paraffin-embedded sections, obviating the need for frozen tissue in many cases. This facilitates the collection, processing, shipping, and storage of tissue specimens for immunohistochemical studies. This report will discuss the basic concepts in the immunohistochemical technique and show its applicability to hematopathology. It will also describe the most relevant antigens/antibodies and how they are used in antibody panels for the diagnosis of benign and malignant hematolymphoid lesions.

CD43 and CD5 antibodies define four normal and neoplastic B-cell subsets: a three-color flow cytometric study

CD43 antibodies are best known for identifying normal and neoplastic T cells and a subset of neoplastic B cells in paraffin sections. The frequency of nonneoplastic CD43 + B cells in different reactive settings, the proportion of B-cell neoplasms with small CD43+ populations, and the relationship of CD43+ B cells was therefore studied in 138 specimens using three-color cytometric analysis. CD43 and CD5 defined four normal B-cell subsets (CD43 + CD5 +, CD43 + CD5-, CD43 - CD5+, and CD43-CD5-). A significantly greater proportion of CD43+ B cells was found in cord blood and putative HIV+ blood samples than in normal control bloods. B-cell neoplasms derived from each of these four B-cell subsets were identified, with CD43+ /CD5+ and CD43-/CD5- neoplasms being most common. The predominant B-cell population coexpressed CD43 alone in 2/39 neoplasms and CD5 alone in four. A minority of cases showed heterogeneous CD43 expression. The B cells in two of three posttransplant lymphoproliferative disorders coexpressed CD43. B cells showed weaker CD43 staining than did T-cells (relative fluorescence 0.38 +/- 0.29). These findings support the concept that CD43 expression by neoplastic B cells is not an aberrant finding. CD43 expression on normal and neoplastic B cells is independent of CD5 expression even though CD43 and CD5 are frequently coexpressed. CD43 expression by B cells sometimes might be underestimated in paraffin sections because it is much weaker than on T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary T-cell immunoblastic lymphoma of the orbit in a pediatric patient

BACKGROUND

The authors report a case of an 8-year-old pediatric patient with a 2-week history of painless periorbital swelling unresponsive to antibiotic treatment.

METHODS

Computed tomography (CT) showed a large, lateral, anterior left orbital soft tissue mass with bony erosion into the anterior cranial fossa through the roof of the orbit laterally. Surgical exploration showed a hard white mass that had eroded through the roof of the left orbit and into the anterior cranial fossa, with herniation of the brain and associated dura through the defect. Results of a complete evaluation of the child for systemic lymphoma, including a lumbar puncture, chest x-ray, bone scan, bone marrow aspirate, and chest/abdomen CT, were negative.

RESULTS

Results of histopathologic and immuno-histochemical evaluation showed a primary orbital T-cell immunoblastic lymphoma. The patient was treated with intrathecal ara-C (Cytosar-U) and methotrexate, 16.2 Gy of whole brain irradiation, and a chemotherapeutic protocol consisting of cyclophosphamide (Cytoxin), vincristine (Oncovin), methotrexate, daunomycin, and prednisone. The patient remains free of lymphoma 33 months after diagnosis, with 20/20 visual acuity in both eyes.

CONCLUSION

The authors believe that this is the youngest documented case of a primary T-cell immunoblastic lymphoma of the orbit.

Monoclonal antibody OPD4 detects neoplastic T cells but does not distinguish between CD4 and CD8 neoplastic T cells in paraffin tissue sections

Monoclonal antibody (MoAb) OPD4, reported to preferentially react with benign CD4 T cells in formalin-fixed tissue sections, was examined for its reactivity with 56 T-cell neoplasms after formalin or Bouin's fixation to determine if it also preferentially detects neoplastic CD4 T cells in paraffin tissue sections. Monoclonal antibody OPD4 did not preferentially detect neoplastic CD4 T cells, since it reacted with 22 of 38 (58%) CD4-positive compared with nine of 14 (64%) CD4-negative T-cell neoplasms. However, MoAb OPD4 appears to detect neoplastic T cells in Bouin's-fixed (11 of 20 cases [55%]) about as well as in formalin-fixed (20 of 32 cases [63%]) tissues. Since MoAb OPD4 does not preferentially react with neoplastic CD4 T cells, the utility of this MoAb as a pan-T-cell marker in routinely processed tissues was also explored and compared with that of Leu-22, UCHL-1, and CD3. All four antibodies reacted with approximately the same percentage of T-cell malignancies (51% to 57%). However, examination of different clinicopathologic groups and types of fixative highlighted differences. Monoclonal antibodies OPD4 and Leu-22 reacted with 62%, while CD3 detected only 41% of formalin-fixed, postthymic T-cell neoplasms. OPD4, UCHL-1, and CD3 each reacted with 55%, but Leu-22 recognized only 45% of Bouin's-fixed, postthymic T-cell malignancies. OPD4 reacted with none, but CD3 reacted with all four T-cell lymphoblastic lymphomas. Various antibody combinations were examined to determine an optimal panel for the recognition of T-cell neoplasms in paraffin sections. The combination of MoAbs OPD4 and Leu-22 detected 86% of postthymic T-cell neoplasms in formalin-fixed tissue sections. Furthermore, MoAb OPD4 appears to be relatively specific for T-cell neoplasms, detecting 31 of 56 (55%) T-cell malignancies, while only reacting with two of 39 (5%) B-cell neoplasms. Therefore, while not preferentially reactive with neoplastic CD4 T cells, MoAb OPD4 may be useful as a pan-T-cell marker of postthymic T-cell neoplasms in routinely processed, formalin-fixed tissues, especially when used in conjunction with MoAb Leu-22.