Relation of CD30 expression to survival and morphology in large cell B cell lymphomas

CD30 in Cutaneous Pathology

ABSTRACT

The discovery of CD30 as a diagnostic marker was essential in the identification of not only some lymphomas but also many other solid tumors and benign reactive conditions. Many CD30+ cutaneous disorders and tumors have been categorized since the identification of the marker. With the design of targeted therapies against CD30+ tumoral cells, the interest in CD30 determination was not only diagnostic but also mainly therapeutic. In this article, we explore the historical aspects of the discovery of CD30 and examine the main CD30-related cutaneous pathology, susceptible of anti-CD30 modern treatments.

Anaplastic variant of diffuse large B-cell lymphoma: Reappraisal as a nodal disease with sinusoidal involvement

Anaplastic variant (av) of diffuse large B-cell lymphoma (DLBCL) is morphologically defined in the 2017 World Health Organization classification, but still an enigmatic disease in its clinicopathologic distinctiveness, posing the differential diagnostic problem from gray zone lymphoma (GZL) and classic Hodgkin lymphoma (cHL). Thirty-one cases previously diagnosed as avDLBCL were reassessed. Of these, 27 (87%) and 4 (13%) were node-based and extranodal diseases, respectively. They were further reclassified into nodal avDLBCL (n = 18), nodal CD30+ DLBCL with T-cell/histiocyte-rich large B-cell lymphoma-like features (CD30+ DLBCL-THRLBCL) (n = 6), GZL with features intermediate between DLBCL and cHL (n = 3) and CD30+ extranodal DLBCL, NOS (n = 4). The nodal avDLBCL cases had a sheet-like proliferation of large cells and/or Hodgkin/Reed-Sternberg (HRS)-like cells in 12 (67%) notably with a sinusoidal pattern in 16 (89%). They showed an expression of CD20 and/or CD79a in all and CD30 in 15 of 18. All of them were negative for PD-L1 on tumor cells, although HRS-like cells showed negativity or partial loss of other B-cell markers to varying degrees. The present study highlighted the distinctiveness of the nodal avDLBCL with sinusoidal pattern, but without neoplastic PD-L1 expression, which provide refined diagnostic criteria for a more precise pathologic and clinical characterization of this disease.

Anaplastic variant of diffuse large B-cell lymphoma with hallmark cell appearance: Two cases highlighting a broad diversity in the diagnostics

The anaplastic variant of diffuse large B-cell lymphoma (A-DLBCL) is morphologically defined but remains an enigmatic disease in its clinicopathologic distinctiveness. Here, we report two cases involving Japanese women aged 59 years, both with A-DLBCL with the hallmark cell appearance and both indistinguishable from common and giant cell-rich patterns, respectively, of anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma. Case 1 was immunohistochemically positive for CD20, CD79a and OCT-2 but not for the other pan-B-cell markers, CD30 and ALK. Case 2 showed CD20 and CD30 positivity for 50% and 20% of tumor cells in addition to strong expression of p53 and MYC. Both were positive for fascin without Epstein-Barr virus association. Our cases provide additional support for the earlier reports that A-DLBCL exhibits clinicopathologic features distinct from ordinal diffuse large B-cell lymphoma (DLBCL), and documented its broader morphologic diversity than previously recognized. They also shed light on the unique feature of absent expression of pan-B-cell markers except for CD20 and CD79a, suggesting that A-DLBCL may biologically mimic a gray zone or intermediate lymphoma between DLBCL and classic Hodgkin lymphoma.

CD30 expression defines a novel subgroup of diffuse large B-cell lymphoma with favorable prognosis and distinct gene expression signature: a report from the International DLBCL Rituximab-CHOP Consortium Program Study

CD30, originally identified as a cell-surface marker of Reed-Sternberg and Hodgkin cells of classical Hodgkin lymphoma, is also expressed by several types of non-Hodgkin lymphoma, including a subset of diffuse large B-cell lymphoma (DLBCL). However, the prognostic and biological importance of CD30 expression in DLBCL is unknown. Here we report that CD30 expression is a favorable prognostic factor in a cohort of 903 de novo DLBCL patients. CD30 was expressed in ∼14% of DLBCL patients. Patients with CD30(+) DLBCL had superior 5-year overall survival (CD30(+), 79% vs CD30(-), 59%; P = .001) and progression-free survival (P = .003). The favorable outcome of CD30 expression was maintained in both the germinal center B-cell and activated B-cell subtypes. Gene expression profiling revealed the upregulation of genes encoding negative regulators of nuclear factor κB activation and lymphocyte survival, and downregulation of genes encoding B-cell receptor signaling and proliferation, as well as prominent cytokine and stromal signatures in CD30(+) DLBCL patients, suggesting a distinct molecular basis for its favorable outcome. Given the superior prognostic value, unique gene expression signature, and significant value of CD30 as a therapeutic target for brentuximab vedotin in ongoing successful clinical trials, it seems appropriate to consider CD30(+) DLBCL as a distinct subgroup of DLBCL.

CD20-negative de novo diffuse large B-cell lymphoma in HIV-negative patients: a matched case-control analysis in a single institution

Background

HIV-negative, CD20-negative de novo diffuse large B-cell lymphoma (DLBCL) patients has rarely been reported. To elucidate the nature of this entity, we retrospectively reviewed the data of 1,456 consecutive de novo DLBCL patients who were treated at Sun Yat-Sen University Cancer Center between January 1999 and March 2011.

Methods

The pathologic characteristics of CD20-negative patients, clinical features, response to initial treatment, and outcomes of 28 patients with available clinical data (n = 21) were reviewed. Then, a matched case-control (1:3) analysis was performed to compare patients with CD20-negative and -positive DLBCL.

Results

The median age of the 28 CD20-negative DLBCL patients was 48 years, with a male-female ratio of 20:8. Seventeen of 22 (77.3%) CD20-negative DLBCL cases were of the non-germinal centre B-cell (non-GCB) subtype. High Ki67 expression (≥80%), an index of cell proliferation, was demonstrated in 17 of 24 (70.8%) cases. Extranodal involvement (≥ 1 site) was observed in 76.2% of the patients. Following initial therapy, 9 of 21 (42.9%) cases achieved complete remission, 4 (19%) achieved partial remission, 1 (4.8%) had stable disease, and 7 (33.3%) had disease progression. The median overall survival was 23 months. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 30.5% and 35%, respectively. A matched case-control analysis showed that patients with CD20-negative and -positive DLBCL did not exhibit a statistically significant difference with respect to the main clinical characteristics (except extranodal involvement), whereas the patients with CD20-positive DLBCL had a better survival outcome with 3-year PFS (P = 0.008) and OS (P = 0.008) rates of 52% and 74.1%, respectively.

Conclusions

This study suggests that HIV-negative, CD20-negative de novo DLBCL patients have a higher proportion of non-GCB subtype, a higher proliferation index, more frequent extranodal involvement, a poorer response, and a poorer prognosis to conventional treatment compared to patients with CD20-positive DLBCL. Further studies are warranted to investigate new target and optimal therapy of CD20-negative de novo DLBCL.

Primary Cutaneous CD30+ Large Cell B-Cell Lymphoma

BACKGROUND

White CD30 expression is described in extracutaneous diffuse large B-cell lymphomas, a primary cutaneous B-cell lymphoma (PCBCL) equivalent is not well defined.

METHODS

Between June 1999 and July 2002 the authors encountered 10 patients with CD30+ PCBCLs of the large cell type.

RESULTS

The patients comprised seven women and three men; five patients were over 80 years of age, all except one presenting with solitary plaques. With the exception of one death from myocardial infarction and one recurrence, all patients are well at a mean follow-up of 23.4 months. Skin biopsies showed a background of T-cell-rich reactive lymphoid hyperplasia in 7 of 10 patients, with variable granulomatous inflammation in 5 cases. The neoplastic large cells were immunoblastic in appearance. In four patients the infiltrate was dominated by large cells. In the remaining patients the reactive infiltrate defined the dominant cell population. The neoplastic cells expressed CD20, CD30, CD43, and BCL-2. In two cases associated with methotrexate therapy, Epstein-Barr virus expression was observed amid the neoplastic cell populace.

CONCLUSIONS

CD30+ PCBCL is a distinctive form of B-cell lymphoma presenting in elderly patients and can be associated with a very good prognosis. In some patients the intensity of reactive inflammation obscures the diagnosis. In the authors' experience almost a third of the cases were associated with Epstein-Barr virus infection and methotrexate therapy, suggesting a distinctive association.

Diffuse large B-cell lymphoma with anaplastic features and focal low-grade mucosa-associated lymphoid tissue lymphoma component of the stomach

We describe an 83-year-old man diagnosed as having diffuse, large B-cell lymphoma with anaplastic features and CD30 expression of the stomach. Focally, the tumor showed typical low-grade mucosa-associated lymphoid tissue lymphoma. We are not aware of a previous report on the transformation of low-grade gastric lymphoma of mucosa-associated lymphoid tissue type into an "anaplastic," large B-cell tumor.

Cytologic and immunocytochemical findings of anaplastic large cell lymphoma: analysis of ten fine-needle aspiration specimens over a 9-year period

BACKGROUND

Anaplastic large cell lymphoma (ALCL) has raised much controversy in the field of hematolymphoid pathology. Its nature is becoming better characterized with recent advances in molecular genetics. However, to the authors' knowledge, a detailed description of the fine-needle aspiration (FNA) cytology of ALCL is lacking and the application of immunocytochemical study, including immunostaining for anaplastic lymphoma kinase (ALK) protein, to cytology samples has not been studied to date.

METHODS

The authors reviewed 10 FNA specimens of ALCL from 8 patients encountered at Pamela Youde Nethersole Eastern Hospital and Queen Mary Hospital in Hong Kong over a 9-year period from early 1993 to the end of 2001. The cytologic and immunocytochemical findings (including ALK protein overexpression) of the specimens were correlated with histologic and immunohistochemical findings of surgical biopsy specimens.

RESULTS

Six of the eight patients had ALCL of the common variant, whereas the remaining two patients had ALCL of the small cell variant. FNA specimens of ALCL of the common variant yielded many loosely dispersed "hallmark" cells that contained eccentric kidney-shaped or embryo-like nuclei, several prominent rod-shaped or angulated basophilic nucleoli, and abundant amphophilic cytoplasm. "Doughnut" cells, tumor cells with multilobated nuclei, and multinucleated giant cells with a wreath-like arrangement of nuclei occasionally were found. A small number of "plasmacytoid" tumor cells, nondescript small round tumor cells, and reactive polymorphs also was present. In contrast, "plasmacytoid" cells and nondescript small to medium-sized tumor cells represented the predominant cell population in ALCL of the small cell variant. The "plasmacytoid" appearance was exaggerated further in air-dried smears. In air-dried smears, small intracytoplasmic vacuoles and scanty azurophilic granules also were noted. On immunocytochemical study performed using the cell block materials, the majority of tumor cells demonstrated membranous and paranuclear "dot-like" positivity for CD30. The staining for epithelial membrane antigen, leukocyte common antigen, and T-cell markers was variable. Positive staining for ALK protein was demonstrated beautifully in two of the cases.

CONCLUSIONS

Despite the wide morphologic spectrum of ALCL, a definitive diagnosis on the basis of FNA cytology is possible on careful interpretation of the cytologic features and a high index of suspicion. The cytologic diagnosis can be confirmed further with proper application of immunostaining to cell block sections. Immunocytochemical study for ALK protein, which provides useful prognostic information, also can be demonstrated satisfactorily using cytology samples.

CD30 expression in follicular lymphoma

CONTEXT

CD30(+) anaplastic large cell lymphomas were originally described as being of T-cell, null cell, and B-cell origin. CD30, however, is not a specific marker of anaplastic large cell lymphoma and has been found to be expressed in reactive as well as neoplastic populations as a probable activation marker. In addition, CD30(+) cells have also been described in both diffuse large B-cell and follicular lymphomas (FLs), resembling the pattern seen in reactive tonsils and lymph nodes.

OBJECTIVE

We report an index case of FL with CD30 expression, which on initial touch preparations and flow cytometric immunophenotyping revealed a prominent population of CD30(+) cells with marked cellular pleomorphism (anaplasia) in a background of typical FL. Immunohistochemistry of the paraffin section for CD30 in our index case confirmed unequivocal CD30(+) pleomorphic cells in the malignant nodules in occasional clusters. This case prompted a study of additional cases of FL for pattern of immunoreactivity with CD30 on paraffin sections.

DESIGN

Twenty-two additional cases of FL (grades 1-3) were retrieved for CD30 immunoperoxidase staining as in the index case.

RESULTS

This study demonstrated 32% of the additional cases of FL had definitive CD30(+), large, pleomorphic malignant cells by paraffin immunohistochemistry. In 2 cases (9%), the pattern of immunoreactivity with CD30 showed clustering and variable staining of large cells, as our index case.

CONCLUSION

This study underscores the morphologic and immunophenotypic spectrum of FL that includes CD30 staining and cellular pleomorphism.

Systemic anaplastic large-cell lymphoma: results from the non-Hodgkin's lymphoma classification project

Anaplastic large-cell lymphoma (ALCL) is a heterogeneous process that may have a T-cell, B-cell, or indeterminant (null) phenotype and which may or may not express the anaplastic lymphoma kinase (ALK) oncoprotein. Because the clinical significance of these variants of ALCL is unclear, we evaluated the cases of ALCL-T/null and ALCL-B identified in the Non-Hodgkin's Lymphoma Classification Project. We evaluated 1,378 cases of non-Hodgkin's lymphoma (NHL), and a consensus diagnosis of ALCL-T/null was made in 33 patients (2.4%) with a diagnostic accuracy of 85%. Compared to 96 patients with other forms of peripheral T-cell lymphoma (PTCL), those with ALCL-T/null were significantly younger, less likely to have advanced-stage disease or bone marrow involvement, more likely to have a low International Prognostic Index score, and had a significantly better survival. Among those with ALCL-T/null, there were no significant differences in the clinical features or survival on the basis of ALK expression. A consensus diagnosis of ALCL-B was made in 15 patients (1.1%), and the diagnostic accuracy was 67%. However, compared to 366 patients with other forms of diffuse large B-cell lymphoma (DLBCL), those with ALCL-B were no different with regard to clinical features or survival. We conclude that patients with ALCL-T/null have favorable prognostic features and excellent survival and should be separated from those with other forms of PTCL for prognostic and therapeutic purposes. In contrast, patients with ALCL-B appear to be similar to those with other forms of DLBCL.

Among diffuse large B-cell lymphomas, T-cell-rich/histiocyte-rich BCL and CD30+ anaplastic B-cell subtypes exhibit distinct clinical features

BACKGROUND

The EORTC clinical trial 20901, activated in 1990, was designed to treat non-Hodgkin's lymphomas (NHL) of intermediate/high-grade malignancy according to the Working Formulation. Established in 1994, the R.E.A.L. Classification on NHL has now replaced all former classifications.

PATIENTS AND METHODS

We reanalysed all cases (n = 273) documented by material available for review according to the R.E.A.L. Classification. In addition, we subdivided cases recognised as diffuse large B-cell lymphoma (DLBCL) into three morphologically distinct categories, namely, large cleaved DLBCL (LC-DLBCL), T-cell-rich/histiocyte-rich B-cell lymphoma (T-cell-rich/histiocyte-rich BCL) and CD30+ DLBCL with anaplastic cell features (CD30+ DLBCL). Finally, T/NULL anaplastic large-cell lymphoma (ALCL) cases were subdivided into ALK+ and ALK- lymphomas. Review was performed independently by two pathologists from two different centres.

RESULTS

DLBCL (61%), T/NULL ALCL (15%) and mantle-cell lymphoma (MCL, 50%) were the main NHL categories represented in the study. Fifty-seven of one hundred sixty DLBCL cases were further subclassified as LC-DLBCL (33 cases), T-cell-rich/histiocyte-rich BCL (13 cases) or CD30+ DLBCL (11 cases). The remaining cases were indicated as unspecified DLBCL. A clinico-pathological correlation confirmed the findings of previous studies suggesting that MCL, DLBCL and ALCL represent distinct entities with MCL being characterised by a short survival, in contrast with the longer survival and less frequent progression typical of ALK+ compared to ALK- ALCL. Within DLBCL, T-cell-rich/histiocyte-rich BCL showed distinctive features at presentation whereas CD30+ DLBCL showed a trend towards a more favourable prognosis, that might be comparable to that of ALK+ ALCL.

CONCLUSIONS

Our data further support the usefulness of the R.E.A.L. Classification and illustrate the feasibility of DLBCL subtyping. Moreover, our results demonstrate the distinct clinical characteristics of T-cell-rich/histiocyte-rich BCL and CD30+ DLBCL with anaplastic cell features suggesting that they may represent clinico-pathologic entities.

Anaplastic large cell lymphomas presented as bone lesions: a clinicopathologic study of six cases and review of the literature

Non-Hodgkin's lymphomas uncommonly present as bone lesions. Most of these tumors are diffuse large B-cell lymphomas. Anaplastic large cell lymphoma (ALCL) presented as bone lesions is exceedingly rare. In this study, we describe six cases of ALCL that presented as solitary or multiple bone lesions. The average patient age was 33 years (range, 4 to 63 years) and the male to female ratio was 2:1. Fever and localized bone pain were the most frequent presenting symptoms. Radiologic examinations revealed osteolytic lesions in all cases, with three (50%) being multiple lesions and five (83%) involving the axial bones. All patients were initially assessed to have only bone involvement. Staging studies revealed mild cervical lymphadenopathy in one patient and no evidence of extraskeletal disease in the other five patients. Histologically, there was diffuse infiltration of one or more bones by large pleomorphic lymphoma cells. Immunohistochemical studies showed all six neoplasms were positive for CD30, EMA, and granzyme B. One case was of T-cell lineage, positive for CD3. One case was positive for the T-cell-associated antigen CD4. The remaining four cases were of null-cell type. In-situ hybridization for EBV was performed in five cases; all were negative. Despite the relatively low International Prognostic Index (IPI) of these patients (mean, 1.67; range, 1 to 3), the overall prognosis was relatively poor: three of six died of disease within 2 years of diagnosis, and two of six were alive with evidence of disease (follow-up, 6 mo to 2 years). Thus, compared to their nodal counterparts, ALCLs that present as bone lesions are distinguished by their uniform expression of EMA and granzyme B, and a relatively poor clinical outcome. Our results also suggest that ALK-1 expression in this clinical setting is not a favorable prognostic indicator.

Anaplastic large-cell lymphomas of B-cell phenotype are anaplastic lymphoma kinase (ALK) negative and belong to the spectrum of diffuse large B-cell lymphomas

There is controversy in the literature as to whether anaplastic large-cell lymphoma of B-cell phenotype is related to the t(2;5)-positive T- or 'null' cell lymphoma of the same morphology. We report a study of 24 lymphomas with morphological features of anaplastic large-cell lymphoma which expressed one or more B-cell markers and lacked T-lineage markers. Clinical features were more in keeping with large B-cell lymphoma than with classical t(2;5)-positive anaplastic large-cell lymphoma, and immunostaining for anaplastic lymphoma kinase (ALK) protein provided no evidence for the (2;5) translocation (or one of its variants). The staining patterns for CD20 and CD79 were typical of diffuse large B-cell lymphoma, CD30 expression was variable, and most cases (15/22) lacked epithelial membrane antigen (EMA). These findings support the view that 'B-cell anaplastic large-cell lymphoma' is unrelated to t(2;5)-positive (ALK-positive) lymphoma, and that it represents a morphological pattern occasionally encountered among diffuse large B-cell lymphomas. By the same reasoning, most tumours diagnosed as 'ALK-negative anaplastic large-cell lymphoma of T-cell or null phenotype' probably belong to the spectrum of peripheral T-cell lymphomas.

Sinusoidal CD30-positive large B-cell lymphoma: a morphologic mimic of anaplastic large cell lymphoma

Anaplastic large cell lymphoma (ALCL) has been recognized recently as a distinct clinicopathologic entity, restricted to a subset of CD30-positive diffuse large cell lymphomas of T/null lineage. Some of the characteristic features of ALCL, such as CD30 antigen expression and the presence of large pleomorphic lymphoid cells infiltrating lymph node sinuses, can be found rarely in diffuse large B-cell lymphomas. We collected 11 such cases, and their clinical, morphologic, and immunophenotypic features are reviewed. The age of the patients ranged from 36 to 82 years (mean, 63.2 years) with a male to female ratio of 1:1.2. All neoplasms were nodal with a sinusoidal infiltrative pattern, although four neoplasms also had foci of confluent growth. Eight tumors were composed predominantly of large pleomorphic cells with occasional Reed-Sternberg-like cells. The other three tumors had a higher proportion of large monomorphic lymphoid cells. Necrosis and admixed granulocytes were other common features. Immunophenotypically, all cases were positive for CD30 and CD20 or CD79a. All eight cases examined for anaplastic lymphoma kinase-1 immunoreactivity were negative. In situ hybridization for Epstein-Barr virus RNA was performed in eight cases; two were positive. Excluding one consultation case with no available clinical follow-up data, six patients died of the disease within 3 years and one had disease relapse within 1 year. We conclude that an unusual variant of diffuse large B-cell lymphoma can closely mimic ALCL. However, these neoplasms can be distinguished from ALCL by virtue of their B-lineage and lack of anaplastic lymphoma kinase-1 expression. Evidence of Epstein-Barr virus infection can be found in a small subset of these neoplasms.

Prognostic Significance of Anaplastic Lymphoma Kinase (ALK) Protein Expression in Adults With Anaplastic Large Cell Lymphoma

Anaplastic large cell lymphoma (ALCL) is an aggressive lymphoma that is frequently associated with the t(2;5)(p23;q35), resulting in expression of a fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), which can be detected by either monoclonal or polyclonal antibodies to the ALK protein. The clinical features of adults with ALCL are incompletely described, and the prognostic factors that are useful for predicting survival remain unclear. This report describes the clinical and laboratory findings in 70 adults with systemic ALCL who were treated with curative intent. We attempted to identify the clinical and pathological factors of prognostic importance, including the International Prognostic Index (IPI), immunophenotype, and expression of the ALK protein. The median age of the patients was 49 years (range, 15 to 75). There were 26 women and 44 men with a median follow-up of 50 months for living patients. Advanced stage was present in 56% and B symptoms were noted in 70% of the patients. Immunostains showed that 46% of the cases had a T-cell phenotype, 36% a null phenotype, and 18% a B-cell phenotype. The expression of ALK protein was found in 51% of the cases. The IPI factors were evenly distributed between the ALK+ and ALK− groups, except that the ALK+ patients were younger (median age, 30 v 61 years; P < .002). The ALK+ cohort included cases with null (44%), T-cell (42%), and B-cell (14%) phenotypes. All 10 cases with cytogenetic or molecular evidence of a t(2;5) were ALK+. The 5-year overall survival (OS) of the entire cohort was 65%. The 5-year OS of the ALK+ and ALK− cases was 79% and 46%, respectively (P < .0003). Analysis of only the T-cell/null cases (n = 57) showed a 5-year OS of 93% for the ALK+ cases and only 37% for the ALK− cases (P < .00001). Univariate analysis of the clinical features showed that age ≤60 years (P < .007), a normal serum lactate dehydrogenase (LDH) (P < .00001), a good performance status (Eastern Cooperative Oncology Group [ECOG] <2) (P< .03), ≤1 extranodal site of disease (P < .012), and an IPI score ≤3 (P < .00001) were associated with improved OS. Although a younger age correlated with ALK positivity, multivariate analysis showed that only a normal serum LDH (P < .00001), an IPI score of ≤3 (P < .0005), and ALK protein expression (P < .005) predicted independently for an improved OS. We conclude that ALCL is a heterogeneous disorder. However, ALK protein expression is an independent predictor of survival and serves as a useful biologic marker of a specific disease entity within the spectrum of ALCL.

Prognostic Significance of Anaplastic Lymphoma Kinase (ALK) Protein Expression in Adults With Anaplastic Large Cell Lymphoma

Anaplastic large cell lymphoma (ALCL) is an aggressive lymphoma that is frequently associated with the t(2;5)(p23;q35), resulting in expression of a fusion protein, nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), which can be detected by either monoclonal or polyclonal antibodies to the ALK protein. The clinical features of adults with ALCL are incompletely described, and the prognostic factors that are useful for predicting survival remain unclear. This report describes the clinical and laboratory findings in 70 adults with systemic ALCL who were treated with curative intent. We attempted to identify the clinical and pathological factors of prognostic importance, including the International Prognostic Index (IPI), immunophenotype, and expression of the ALK protein. The median age of the patients was 49 years (range, 15 to 75). There were 26 women and 44 men with a median follow-up of 50 months for living patients. Advanced stage was present in 56% and B symptoms were noted in 70% of the patients. Immunostains showed that 46% of the cases had a T-cell phenotype, 36% a null phenotype, and 18% a B-cell phenotype. The expression of ALK protein was found in 51% of the cases. The IPI factors were evenly distributed between the ALK+ and ALK− groups, except that the ALK+ patients were younger (median age, 30 v 61 years; P < .002). The ALK+ cohort included cases with null (44%), T-cell (42%), and B-cell (14%) phenotypes. All 10 cases with cytogenetic or molecular evidence of a t(2;5) were ALK+. The 5-year overall survival (OS) of the entire cohort was 65%. The 5-year OS of the ALK+ and ALK− cases was 79% and 46%, respectively (P < .0003). Analysis of only the T-cell/null cases (n = 57) showed a 5-year OS of 93% for the ALK+ cases and only 37% for the ALK− cases (P < .00001). Univariate analysis of the clinical features showed that age ≤60 years (P < .007), a normal serum lactate dehydrogenase (LDH) (P < .00001), a good performance status (Eastern Cooperative Oncology Group [ECOG] <2) (P< .03), ≤1 extranodal site of disease (P < .012), and an IPI score ≤3 (P < .00001) were associated with improved OS. Although a younger age correlated with ALK positivity, multivariate analysis showed that only a normal serum LDH (P < .00001), an IPI score of ≤3 (P < .0005), and ALK protein expression (P < .005) predicted independently for an improved OS. We conclude that ALCL is a heterogeneous disorder. However, ALK protein expression is an independent predictor of survival and serves as a useful biologic marker of a specific disease entity within the spectrum of ALCL.

CD30 in normal and neoplastic cells

In 1982 Stein and coworkers identified a new molecule, CD30 (Ki-1), which is expressed by Reed-Sternberg (RS) cells of Hodgkin's Disease (HD) (1). Although CD30 is not a specific RS cell marker, its characterization has assumed an important role not only in the differential diagnosis of HD, but also in the identification of a morphologically and clinically distinct type of large cell lymphoma, now designated as anaplastic large cell lymphoma (ALCL) (2). The cloning of human and murine CD30 and the utilization of genetically manipulated animal models have rapidly expanded our knowledge on its physiological role in lymphoid development and differentiation. The goal of this review is to present an overview of this rapidly evolving field and discuss the role of CD30 in normal and neoplastic lymphoid cells.

Anaplastic large cell lymphoma: a distinct molecular pathologic entity: a reappraisal with special reference to p80(NPM/ALK) expression

The p80(NPM/ALK) expression activated by the t(2;5) (p23;q35) translocation recently has been shown to play an important role in the pathogenesis of anaplastic large cell lymphoma (ALCL). However, the clinicopathologic significance of identification of p80 among ALCL cases has not been completely resolved. Difficulties also exist in the histologic and immunophenotypic identification of ALCL and Hodgkin's disease (HD) as separate processes, often complicating the clinicopathologic evaluation of and therapeutic approach to these entities. In order to clarify these issues, 67 specimens of ALCL and 63 specimens of HD (31 of the nodular-sclerosing type [NS-HD] and 32 of the mixed-cellularity type [MC-HD]) were immunostained using anti-p80 antibody and other relevant markers on paraffin sections. The clinicopathologic and immunophenotypic features were reviewed on the basis of p80 reactivity. The expression of p80 was detected in 43 of 67 cases of ALCL (64%), but none of HD. The p80+ ALCL cases constituted a very homogeneous group of tumors, characterized by the occurrence in a much younger group and relatively more favorable clinical course than the p80- ALCL, which were in keeping with the data previously reported. They showed virtually the identical immunophenotypic findings of p80+, CD30+, EMA+, CD15-, bcl-2-, and Epstein-Barr virus (EBV) with T- and null-cell phenotype, and showed the distinct morphologic features, including three cases of lymphohistiocytic/small-cell variant, as follows: the indented nuclei, often termed as reniform, embryolike, and horseshoelike; multiple, irregular, but indistinct nucleoli; and few reactive cells of eosinophils and epithelioid cells. Conversely, the 24 p80- ALCL cases, in which epithelial membrane antigen (EMA) and bcl-2 positivities were 33% and 55%, respectively, were heterogeneous and could be subdivided into five different categories, namely (a) 11 cases of HD-like ALCLs, (b) six cases of p80 common ALCL, (c) three cases of secondary ALCL, (d) two cases of primary cutaneous ALCL, and (e) two cases of primary classical ALCL that lacked p80 expression. This study clearly demonstrated that the immunohistochemical detection of p80 is of a crucial importance in delineating the biologically distinct entity of "primary classical ALCL" from various diseases that show morphologic and immunohistologic overlap, including HD and HD-like ALCL.

Cytotoxic Cell Antigen Expression in Anaplastic Large Cell Lymphomas of T- and Null-Cell Type and Hodgkin's Disease: Evidence for Distinct Cellular Origin

Anaplastic large cell lymphoma (ALCL) is composed of large, frequently bizarre, cells of T- or null-cell phenotype that show a preferential sinusoidal growth pattern and consistent CD30 positivity. Whether these tumors represent a single entity or several, and what the exact cell origin, is controversial. Recently, granzyme B, a cytotoxic granule component, was reported in a small percentage of ALCL, suggesting that some cases may originate from cytotoxic lymphocytes. To further investigate this possibility, we performed an immunohistochemical study of 33 ALCLs of T- and null-cell type, using monoclonal antibodies to cytotoxic cell-associated antigens, including CD8, CD56, CD57, and the cytotoxic granular proteins perforin and TIA-1. In addition, CD4 expression was also evaluated. ALCL cases included 27 classical systemic forms and variants, 3 primary cutaneous (PC) forms, and 3 acquired immunodeficiency syndrome-associated forms. Cytotoxic antigen expression was also studied in 51 cases of Hodgkin's disease (HD) and 17 large B-cell lymphomas (LBCLs) with anaplastic cytomorphology and/or CD30 positivity. We found that 76% of ALCLs, representing all subtypes except the PC forms, expressed either TIA-1, perforin, or both proteins. Expression of TIA-1 and perforin were highly correlated (P < .001). On the basis of their immunophenotypic profiles, several subtypes of cytotoxic antigen positive and negative ALCL could be recognized. Fifty-five percent of ALCLs (18 of 33) displayed an immunophenotypic profile consistent with cytotoxic T cells. Six cases expressed cytotoxic granular proteins in the absence of lineage specific markers, and one case expressed both T-cell – and natural killer cell–like markers. These 7 cases (21%) were placed into a phenotypic category of cytotoxic lymphocytes of unspecified subtype. Twenty-four percent (8 cases) of ALCLs were cytotoxic granule protein negative. All but one of these displayed a T-cell phenotype. Cytotoxic granule protein expression did not correlate with the presence of the NPM-ALK fusion transcript. Only 10% of the 51 HD cases were found to be TIA-1+, and none expressed perforin. Cytotoxic antigen expression was absent in LBCL. The expression of cytotoxic granule proteins in the majority of ALCL implies a cytotoxic lymphocyte phenotype and suggests that most cases originate from lymphocytes with cytotoxic potential. Furthermore, the demonstration of cytotoxic cell related proteins may be a useful addition to the current panel of antibodies used to distinguish ALCL, HD, and anaplastic LBCL.

Mediastinal large B-cell lymphoma: clinical and immunohistological findings in 18 patients treated with different third-generation regimens

We report on the immunophenotype, clinical findings and response to aggressive chemotherapy of 18 patients with mediastinal large B-cell lymphoma (MLCL). Cases were collected from a series of 286 high-grade non-Hodgkin's lymphomas (HG-NHL) which, in the period September 1988 to August 1991, were enrolled in a prospective multicentre trial designed to compare the MACOP-B and F-MACHOP regimens. Immunostaining on frozen sections revealed a previously unrecognized phenotype, i.e. co-expression of B-cell (CD19, CD20, CD22, Ig-associated dimer) and activation-associated antigens (CD30 and CDw70) in about 60% of MLCL cases; in contrast, the activation-associated antigens CD25 and Ki-27 (unclustered) were consistently negative. This peculiar phenotype may reflect a derivation of the tumour from a subset of thymic activated B cells. Clinically, the patients (median age 31 years; F/M ratio 2.6) presented with bulky mediastinal mass (72%) associated with mediastinal syndrome in > 50% cases; disease was stage IIA in most cases. All 18 patients received aggressive chemotherapy (F-MACHOP 11; MACOP-B 7). Complete response (CR) was achieved in 57.1% of cases treated with MACOP-B. In contrast, the response of the 11 MLCL treated with F-MACHOP was poor (CR 18.2%) as compared to that of the 135 HG-NHL treated with the same regimen during the trial (CR 69.6%). This difference was still statistically significant after adjusting for negative prognostic factors (mediastinal mass > 10 cm plus increased LDH) and suggests that F-MACHOP might not be the most appropriate regimen for this kind of lymphoma.