Hodgkin disease, nodular sclerosis type. Implications of histologic subclassification

Mediastinal Lymphoproliferative Disorders

Lymphoproliferative disorders comprise 50% to 60% of all mediastinal malignancies in both children and adults. Primary mediastinal involvement is rare (∼5%), whereas secondary mediastinal involvement by systemic disease is more common (10% to 25%). Primary mediastinal disease is defined as involvement by a lymphoproliferative disorder of mediastinal lymph nodes, the thymus, and/or extranodal mediastinal organs without evidence of systemic disease at presentation. In this review, the clinical, radiologic, histopathologic, immunohistochemical, and genetic features of some of the most characteristic mediastinal lymphoproliferative disorders are presented. The entities discussed here include: classic Hodgkin lymphoma with emphasis on nodular sclerosis and mixed cellularity types, and non-Hodgkin lymphomas, including primary mediastinal (thymic) large B-cell lymphoma, mediastinal gray zone lymphoma, mediastinal diffuse large B-cell lymphoma, thymic marginal zone lymphoma, mediastinal plasmacytoma, T-lymphoblastic lymphoma, and anaplastic large cell lymphoma. Although not a malignant process, hyaline vascular Castleman disease is also discussed here as this disorder commonly involves the mediastinum. Despite multiple advances in hematopathology in recent decades, the day-to-day diagnosis of these lesions still requires a morphologic approach and a proper selection of immunohistochemical markers. For this reason, it is crucial for general pathologists to be familiar with these entities and their particular clinicoradiologic presentation.

Histology of pediatric classic Hodgkin lymphoma: From diagnosis to prognostic stratification

AIMS

Classic Hodgkin lymphoma (cHL) is a common malignancy of the pediatric age. Although clinical-radiological features are routinely used for disease risk stratification, the role of tumor histology has yet to be defined. This study aimed to characterize the clinical-pathological features of a large cohort of pediatric cHL specifically investigating the relevance of tumor histology for the prognostic stratification of patients.

METHODS AND RESULTS

The study considered 96 clinically annotated cases of pediatric cHL treated according to the AIEOP-LH2004 protocol. The following histological parameters were considered: (i) cHL variant; (ii) grade of nodular sclerosis (NS); (iii) staining for Bcl2 and p53, and expression of B-cell (BCA) and T-cell antigens (TCA) by Hodgkin/Reed-Sternberg cells. The study population consisted of 51 males and 45 females (median age: 13.6 years) with five-year overall and progression-free survival of 94% and 81%, respectively. Most cases featured NS morphology (96%) with a prevalence of NS1 over NS2 grades. Two NS2 variants were recognized (sarcomatous/syncytial and fibrohistiocytic). A consistent subset of cases disclosed positivity for BCA (34%), TCA (26%), p53 (13%), and Bcl2 (19%). Clinical-pathological correlations showed a more aggressive clinical course for NS2 over NS1 cases. The NS2 fibrohistiocytic variant was associated with the worst outcome. No other histological features correlated with prognosis.

CONCLUSIONS

Pediatric cHL is a clinically and histologically heterogeneous neoplasm. The majority of cases disclose NS morphology and aberrant phenotypes are frequently encountered. In the pediatric population, NS grading and NS2 subtyping bear significant prognostic impact.

Clinicopathologic consensus study of gray zone lymphoma with features intermediate between DLBCL and classical HL

Gray zone lymphoma (GZL) is described as sharing features with classical Hodgkin lymphoma (cHL) and diffuse large B-cell lymphoma (DLBCL). However, there remains complexity in establishing diagnosis, delineating prognosis, and determining optimum therapy. Sixty-eight cases diagnosed as GZL across 15 North American academic centers were evaluated by central pathology review to achieve consensus. Of these, only 26 (38%) were confirmed as GZL. Morphology was critical to GZL consensus diagnosis (eg, tumor cell richness); immunohistochemistry showed universal B-cell derivation, frequent CD30 expression, and rare Epstein-Barr virus (EBV) positivity (CD20⁺, 83%; PAX5⁺, 100%; BCL6⁺, 20%; MUM1⁺, 100%; CD30⁺, 92%; EBV⁺, 4%). Forty-two cases were reclassified: nodular sclerosis (NS) cHL, n = 27 (including n = 10 NS grade 2); lymphocyte predominant HL, n = 4; DLBCL, n = 4; EBV⁺ DLBCL, n = 3; primary mediastinal large BCL n = 2; lymphocyte-rich cHL and BCL-not otherwise specified, n = 1 each. GZL consensus-confirmed vs reclassified cases, respectively, more often had mediastinal disease (69% vs 41%; P = .038) and less likely more than 1 extranodal site (0% vs 25%; P = .019). With a 44-month median follow-up, 3-year progression-free survival (PFS) and overall survival for patients with confirmed GZL were 39% and 95%, respectively, vs 58% and 85%, respectively, for reclassified cases (P = .19 and P = .15, respectively). Interestingly, NS grade 2 reclassified patients had similar PFS as GZL consensus-confirmed cases. For prognostication of GZL cases, hypoalbuminemia was a negative factor (3-year PFS, 12% vs 64%; P = .01), whereas frontline cyclophosphamide, doxorubicin, vincristine, and prednisone ± rituximab (CHOP±R) was associated with improved 3-year PFS (70% vs 20%; P = .03); both factors remained significant on multivariate analysis. Altogether, accurate diagnosis of GZL remains challenging, and improved therapeutic strategies are needed.

Nomograms for predicting the overall and cancer-specific survival of patients with classical Hodgkin lymphoma: a SEER-based study

The aim of this study was to establish nomograms, based on significant clinicopathologic parameters, for predicting the overall survival (OS) and the cancer-specific survival (CSS) of patients with classical Hodgkin lymphoma (CHL). The data of 43,330 CHL patients, diagnosed between 1983 and 2014, were obtainedfrom the database of the Surveillance, Epidemiology, and End Results (SEER) program. These patients were randomly divided into training (n = 30,339) and validation (n = 12,991) cohorts. The Kaplan-Meier method and Cox proportional hazards regression model were used to evaluate the prognostic effects of multiple clinicopathologic parameters on survival. Significant prognostic factors were combined to build nomograms. The predictive performance of nomograms was evaluated using the index of concordance (C-index) and calibration curves. In the training cohort, on univariate and multivariate analyses, age at diagnosis, gender, race, Ann Arbor stage, and histological type significantly correlated with the survival outcomes. These characteristics were used to establish nomograms. The nomograms showed good accuracy in predicting 1-, 5-, and 10-year OS and CSS, with a C-index of 0.794 (95% confidence interval [CI], 0.789-0.799) for OS and 0.760 (95% CI, 0.753-0.767) for CSS. In the validation cohort, the C-index for nomogram-based predictions was 0.787 (95% CI, 0.779-0.795) for OS and 0.769 (95% CI, 0.758-0.780) for CSS. All calibration curves revealed excellent consistency between predicted and actual survival. In summary, novel nomograms were established and validated to predict OS and CSS for patients with CHL. These new prognostic models could aid in improved prediction of survival outcomes leading to reasonable treatment recommendations.

Differences in outcome of patients with syncytial variant Hodgkin lymphoma compared with typical nodular sclerosis Hodgkin lymphoma

BACKGROUND

Nodular sclerosis Hodgkin lymphoma (NS-HL) is the most common subtype of HL and usually has a good prognosis. A variant of NS, the syncytial variant (SV) has well-established histopathologic features but little is known about its clinical behavior. Small case series have suggested that SV patients present with advanced disease and have a comparatively aggressive course. The objective of this study was to determine the clinical characteristics and outcome of SV patients.

METHODS

A total of 167 adult patients with NS-HL including 43 patients with SV and 124 patients with typical NS (t-NS) were included in our analysis following institutional review board (IRB) approval. The Kaplan-Meier method was used to calculate the progression-free survival (PFS) and overall survival (OS). Log-rank test was used to determine the differences in survival.

RESULTS

Of the 167 patients, 43 were confirmed as SV based on morphology and immunophenotype. Doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) was the most frequent induction regimen administered in 91% of all patients. The rate of complete response (CR) in the SV group was 74% versus 87% in the t-NS group (p = 0.05). At 49 months follow up, the PFS was 17 months in the SV group and not reached in the t-NS group [p < 0.0001; hazard ratio (HR) = 3.695; 95% confidence interval (CI) = 3.0, 11.07]. The median OS was not reached in both groups (p = 0.32).

CONCLUSIONS

Our results show that SV histology represents a poor risk group with lower CR rate and shorter PFS and this should be considered in the risk stratification of classical HL patients.

Primary Mediastinal Classical Hodgkin Lymphoma

Primary mediastinal Classical Hodgkin lymphoma (CHL) is rare. Nodular sclerosis CHL (NS-CHL) is the most common subtype involving the anterior mediastinum and/or mediastinal lymph nodes. Primary thymic CHL is exceedingly rare. The disease typically affects young women and is asymptomatic in 30% to 50% of patients. Common symptoms include fatigue, chest pain, dyspnea and cough, but vary depending on the location and size of the tumor. B-symptoms develop in 30% of cases. By imaging, primary mediastinal CHL presents as mediastinal widening/mediastinal mass that does not invade adjacent organs but may compress vital structures as bulky disease. Histopathology is the gold standard for diagnosis. Primary mediastinal NS-CHL consists of nodules of polymorphous inflammatory cells surrounded by broad fibrous bands extending from a thickened lymph node capsule. The cellular nodules contain variable numbers of large Hodgkin/Reed-Sternberg cells, required for diagnosis. Primary thymic CHL may exhibit prominent cystic changes. The histopathologic recognition of NS-CHL can be challenging in cases with prominent fibrosis, scant cellularity, artifactual cell distortion, or an exuberant granulomatous reaction. The differential diagnosis includes primary mediastinal non-HLs, mediastinal germ cell tumors, thymoma, and metastatic carcinoma or melanoma to the mediastinum. Distinction from primary mediastinal non-HLs is crucial for adequate therapeutic decisions. Approximately 95% of patients with primary mediastinal CHL will be alive and free of disease at 10 years after treatment with short courses of combined chemoradiotherapy. In this review, we discuss the history, classification, epidemiology, clinicoradiologic features, histopathology, immunohistochemistry, differential diagnosis, and treatment of primary mediastinal CHL.

Prognostic factors in hodgkin lymphoma

Hodgkin lymphoma (HL) is among the neoplastic diseases that has the best long-term outcome after cytotoxic treatment. Cure rates approach 80–90%; however, 15–20% of patients will be resistant to therapy (primary refractory) or relapse after treatment. Prognostic factors should help to stratify treatment according to the risk profile and identify patients at risk for failure. Significance of prognostic factors partly depends on the efficacy of the treatments administered, since new effective therapies can variably counterbalance the adverse effects of some unfavorable clinical determinants. As a consequence, some prognostic factors thought to be important in the past may become meaningless when modern successful therapies are used. Therefore, the value of prognostic factors has to be updated periodically, and then adapted to new emerging biomarkers. Besides the prognostic role of PET imaging, tissue and circulating biomarkers, as the number of tumor-infiltrating macrophages, cytokine and chemokine levels and profiling of circulating nucleic acids (DNA and microRNAs) have shown promise.

The ratio of the absolute lymphocyte count to the absolute monocyte count is associated with prognosis in Hodgkin's lymphoma: correlation with tumor-associated macrophages

BACKGROUND

Although most patients with classical Hodgkin's lymphoma (cHL) have a long survival duration, the current risk stratification is imperfect. A recent study suggested a prognostic role for the peripheral blood absolute lymphocyte count/absolute monocyte count (ALC/AMC) ratio at diagnosis in cHL. It is intriguing to investigate the significance of the ALC/AMC ratio in relation to tumor-associated macrophages (TAMs), yet another prognostic factor for cHL.

METHODS

We examined the prognostic impact of the ALC, AMC, and ALC/AMC ratio in 312 cHL patients (median age, 37 years) using receiver operating characteristic curve analysis for optimal cutoff values, and compared these with TAM content.

RESULTS

The median follow-up was 65 months (range, 0.1-245 months). On univariate analysis, a low ALC/AMC ratio (<2.9) was correlated with a poorer overall survival (OS) outcome. A subgroup analysis of patients with limited-stage disease showed that the ALC/AMC ratio was significantly correlated with the OS time. Multivariate analysis showed the ALC/AMC ratio to be an independent prognostic factor for OS outcome. A Spearman correlation test of TAM content showed a negative correlation with the ALC/AMC ratio and a positive correlation with the peripheral blood macrophage percentage.

CONCLUSIONS

This study suggests that the ALC/AMC ratio may be a simple, inexpensive, and independent prognostic factor for OS outcome in patients with cHL and may have a role in the stratification of cHL patients in addition to the International Prognostic Score and TAM content.

CD68 and CD163 as prognostic factors for Korean patients with Hodgkin lymphoma

BACKGROUND

Limited progress had been made in prognostic stratification of patients with Hodgkin lymphoma (HL) until recent studies suggested that the number of CD68-expressing macrophages is prognostic in classical HL. However, its significance in Asian patients with HL has not been explored yet perhaps because of its low incidence in Asia.

METHODS

In this work, we performed immunohistochemical analysis of CD163, as well as CD68, in 144 Korean patients with HL treated between November 1990 and December 2009 in a single center. The relative percentages of CD68+ and CD163+ cells with respect to the overall cellularity (CD68 index and CD163 index, respectively) were correlated with clinical outcomes.

RESULTS

Both high CD68 and CD163 indices (>20%) were associated with a rise in treatment-related deaths and poorer event-free survival (P = 0.009 and P = 0.0023, respectively), disease-specific survival (P = 0.011 and P = 0.001), and overall survival (P = 0.023 and P = 0.001). In particular, a high CD163 index was related to lower complete response (CR) rate (P = 0.022) and shorter duration of CR (P = 0.030).

CONCLUSIONS

High index of either CD68 or CD163 (>20%) is significantly correlated with poor prognosis in Korean patients with HL. CD163, a specific marker of macrophages, seems to be another prognostic factor for classical HL.

Pathobiology of hodgkin lymphoma

Despite its well-known histological and clinical features, Hodgkin's lymphoma (HL) has recently been the object of intense research activity, leading to a better understanding of its phenotype, molecular characteristics, histogenesis, and possible mechanisms of lymphomagenesis. There is complete consensus on the B-cell derivation of the tumor in most cases, and on the relevance of Epstein-Barr virus infection and defective cytokinesis in at least a proportion of patients. The REAL/WHO classification recognizes a basic distinction between lymphocyte predominance HL (LP-HL) and classic HL (cHL), reflecting the differences in clinical presentation and behavior, morphology, phenotype, and molecular features. cHL has been classified into four subtypes: lymphocyte rich, nodular sclerosing, with mixed cellularity, and lymphocyte depleted. The borders between cHL and anaplastic large-cell lymphoma have become sharper, whereas those between LP-HL and T-cell-rich B-cell lymphoma remain ill defined. Treatments adjusted to the pathobiological characteristics of the tumor in at-risk patients have been proposed and are on the way to being applied.

Does bulky disease at diagnosis influence outcome in childhood Hodgkin's disease and require higher radiation doses? Results from the German-Austrian Pediatric Multicenter Trial DAL-HD-90

PURPOSE

The identification of risk factors is required for risk-adapted treatment strategies in the treatment of Hodgkin's disease. To assess the influence of bulky disease at diagnosis as compared with other risk factors on event-free survival (EFS) in pediatric Hodgkin's disease such as stage, B-symptoms, number of involved lymph node regions, histology, and remission status after chemotherapy, we analyzed the outcome of 552 patients treated with a risk-adapted treatment strategy consisting of OPPA(OEPA)/COPP (vincristine, procarbazine, etoposide, prednisone, adriamycin, cyclophosphamide) and involved-field radiotherapy.

METHODS AND MATERIALS

Between 1990 and 1995, 578 patients with primary Hodgkin's disease (HD) were enrolled in the German/Austrian Pediatric Hodgkin's Disease Study Group (DAL) Multicenter Study (HD-90). Patients were stratified into three treatment groups (TGs) for early, intermediate, and advanced stage. All patients received induction chemotherapy (CT) with two cycles of OEPA for boys and two cycles of OPPA for girls. Patients in TG2 and TG3 received another two or four cycles, respectively, of COPP. Chemotherapy was followed by involved-field radiotherapy. The radiation field, which was prescribed by the study center, was treated with a dose of 25 Gy/25 Gy/20 Gy (TG1/TG2/TG3), and in case of insufficient remission with a local boost of 5 Gy to 10 Gy. The following prognostic factors were analyzed with regard to their impact on EFS: bulky disease, mediastinal tumor, number of involved lymph node regions, histology, treatment group, B-symptoms, sex, age, and remission status after chemotherapy.

RESULTS

Significant univariate predictive factors for the EES were: nodular sclerosis type 2 (NS2) histology (relative risk [RR] 3.43; p = 0.0002), presence of B-symptoms (RR 2.70; p = 0.0014), number of involved regions (1.55; p = 0.019), and treatment groups (RR 1.33; p = 0.017). There was a higher risk (RR 1.92; p = 0.040) for patients with bulky compared with nonbulky disease (5-year EFS 89.6%/94.6%). In the multiple regression model, only NS2 and B-symptoms remained strong predictive factors. The remission status after chemotherapy did not correlate with EFS (p = 0.66).

CONCLUSION

Treatment strategies in Hodgkin's disease have an impact on different risk factors. In the risk-adapted treatment strategy of the HD-90 study, tumor burden indicated as bulky disease or as number of involved lymph nodes loses its importance, whereas NS2 histology and B-symptoms have a major impact on treatment outcome. Bulky disease at diagnosis might require higher radiation doses only in case of insufficient remission.

Nodular sclerosing Hodgkin disease: new grading predicts prognosis in intermediate and advanced stages

The prognostic value of histologic classification and single histomorphologic parameters in Hodgkin disease has been widely debated in the literature. Whereas several former studies identified single parameters to be of clinical relevance, some recent reports have doubted the prognostic value of histology using modern treatment. Grading of the largest histologic category of Hodgkin disease, nodular sclerosis (NS), has been controversially discussed concerning clinical relevance. In this study, 965 cases of NS were reviewed to assess 9 histomorphologic parameters. The histologic results were correlated with laboratory and clinical findings and with overall survival and disease-free survival. Based on these results, a new grading of the NS category was established. The new grading, based on the 3 criteria eosinophilia, lymphocyte depletion, and atypia of the Hodgkin/Reed-Sternberg cells, was a significant indicator of prognosis in intermediate and advanced stages. Patients investigated in this study represent an outstanding collection because all of them were enrolled in the prospective multicenter clinical trial of the German Hodgkin Lymphoma Study Group. All of them had been staged uniformly according to the Ann Arbor system and had received stage-adapted modern treatment according to multimodality protocols. A subtle analysis of histology could represent a possible way to identify patients with a significantly better or worse prognosis. This new grading should help to avoid overtreatment to reduce severe therapy-related side effects such as acute toxicity and chronic sequelae such as cardiopulmonary complications and secondary neoplasias.

Hodgkin's lymphoma: the pathologist's viewpoint

Despite its well known histological and clinical features, Hodgkin's lymphoma (HL) has recently been the object of intense research activity, leading to a better understanding of its phenotype, molecular characteristics, histogenesis, and possible mechanisms of lymphomagenesis. There is complete consensus on the B cell derivation of the tumour in most cases, and on the relevance of Epstein-Barr virus infection and defective cytokinesis in at least a proportion of patients. The REAL/WHO classification recognises a basic distinction between lymphocyte predominance HL (LP-HL) and classic HL (CHL), reflecting the differences in clinical presentation and behaviour, morphology, phenotype, and molecular features. CHL has been classified into four subtypes: lymphocyte rich, nodular sclerosing, with mixed cellularity, and lymphocyte depleted. The borders between CHL and anaplastic large cell lymphoma have become sharper, whereas those between LP-HL and T cell rich B cell lymphoma remain ill defined. Treatments adjusted to the pathobiological characteristics of the tumour in at risk patients have been proposed and are on the way to being applied.

Hodgkin's lymphoma of T-cell type: clonal association with a CD30+ cutaneous lymphoma

The derivation of Reed-Sternberg cells in Hodgkin's lymphoma has been a subject of great interest. In most cases, Reed-Sternberg cells seem to be derived from germinal center B cells. In few sporadic cases, a T-cell origin has been shown. This article supports the concept of a T-cell derivation for rare cases of Hodgkin's lymphoma and provides evidence of a novel mechanism of pathogenesis from chronic inflammation in the skin.

The correlation of Epstein-Barr virus expression and lymphocyte subsets with the clinical presentation of nodular sclerosing Hodgkin disease

BACKGROUND

The pathogenesis of nodular sclerosing Hodgkin disease (HD) has been correlated with Epstein-Barr virus (EBV). The phenotype of lymphocytes in HD and its relations to clinical presentation and to EBV expression have not been characterized fully. Grade II HD is a more aggressive form of the disease. The authors studied cases of HD by flow cytometry (FCM) in an attempt to analyze the phenotype of lymphocytes in the involved lymph nodes and to characterize the phenotype of these lymphocytes in relation to EBV expression, tumor grade, and clinical presentation. MATERIALS AND METHODS The authors prospectively studied lymph nodes from 48 patients with the diagnosis of HD by FCM for T (CD3, CD4, and CD8) and B (CD19) lymphocytes. Ratios of helper to suppressor (CD4 to CD8) and ratios of T to B (CD3 to CD19) lymphocytes were calculated. In situ hybridization for EBV also was performed. The tumors were graded. Clinical data related to age and stage of the disease were retrospectively analyzed.

RESULTS

There were 30 male and 18 female patients with an age range of 7 to 77 years (median, 17 yrs). EBV expression was seen in 24 (50%) cases. Eleven (23%) cases were classified as Grade II disease. All Grade II cases showed EBV expression, whereas only 13 (39%) cases of Grade I disease were positive (P = 0.03). EBV-positive cases had a median CD4 to CD8 ratio of 1.62, whereas EBV-negative cases had a ratio of 3.86 (P = 0.01). Grade I cases had a median CD4 to CD8 ratio of 4.58, whereas Grade II cases had a ratio of 1.62 (P = 0.007). EBV-positive cases had a median T-lymphocyte to B-lymphocyte ratio of 2.72, whereas EBV-negative cases had a ratio of 3.17 (P = 0.77). Grade I cases had a median T-lymphocyte to B-lymphocyte ratio of 3.51, whereas Grade II cases had a ratio of 1.71 (P = 0.001). A higher percentage of children was seen in the EBV-positive cases than in the negative ones (58% vs. 29%). Cases with low (< 1.5) CD4 to CD8 ratios showed more incidence of high-stage disease (Stages III and IV) than patients with higher ratios (81% vs. 51%). High-stage disease also was seen more frequently in patients with low (< 3) T- to B-lymphocyte ratios (71% vs. 50%).

CONCLUSION

The authors found that the local immune response in HD may vary from one case to another. The findings also suggest that EBV may play a role in the pathogenesis of the disease in relation to T- and B-lymphocyte response. A more profound immune suppression and decrease in overall T and helper lymphocytes may be seen in aggressive EBV-positive variants of the disease. These changes may impact the initial presentation of the disease and perhaps its overall biologic behavior.

Thymic Hodgkin's disease--a histological and immunohistochemical study of three cases

Thymic Hodgkin's disease (HD) shows some peculiar histological features different from nodal disease which are a result of the interaction with the specific thymic microenvironment. We describe the histological and immunohistochemical findings in three cases presenting as a primary thymic neoplasm both clinically and radiologically. Histological hallmarks were the prominent formation of epithelium-lined cysts, inflammatory changes, a marked proliferation of thymic epithelium in association with Hodgkin- and Reed-Sternberg (RS) cells and the occurrence of the nodular sclerosing subtype in all cases. The immunophenotype of the neoplastic cells was that of classical HD. They expressed CD30, CD15 and lacked CD45. In two cases CD20 expression was observed. All cases were negative for the latent membrane protein (LMP) of the Epstein-Barr virus (EBV). The accompanying inflammatory infiltrate was rich in mature T-cells, but also showed a significant number of B-cells with frequent formation of follicles and proliferation of follicular dendritic cells. Thymic HD develops in a microenvironment with features of thymic medulla as defined by the morphology and pattern of the proliferating epithelial cells and the mature immunophenotype of the admixed thymocytes. These findings, especially the CD20 positivity in Hodgkin and RS-cells, may point to the possible origin of thymic HD from medullary B-cells.

Prognostic factors affecting disease-free survival in patients with Hodgkin's disease stages IA and IIA treated initially with radiotherapy alone in a single centre during 1973 to 1992

One hundred forty-nine patients with either stage IA (90 patients) or stage IIA (59 patients) Hodgkin's disease (HD) received radiotherapy alone as their first line treatment. Only stage of the nine factors selected for Cox multivariate analysis was of prognostic significance. Patients with grade 1 nodular sclerosing HD did not have a significantly better disease-free survival than those with grade 2 disease.

Prognostic value of follicular dendritic cells in nodular sclerosing Hodgkin's disease

AIMS

In nodular sclerosing Hodgkin's disease (NSHD), the prognostic relevance of the histopathological grading in two subtypes NSI (low-grade) and NSII (high-grade) remains controversial. Analysis of follicular dendritic cells (FDC) may provide new prognostic parameters.

METHODS AND RESULTS

Tumours from 59 patients with NSHD were studied. Mean follow-up time was 8 years. Forty-one cases were classified as NSI and 18 as NSII. FDC were immunostained with the paraffin-resistant monoclonal antibodies CD21 and CNA.42. We distinguished three patterns in the neoplastic tissue: FDC1, the presence of well-defined follicle-like structures (n = 20); FDC2, the presence of largely destroyed FDC networks (n = 25); and FDC3, no or a few isolated FDC (n = 14). The three groups differed clearly regarding the frequency of relapse and the survival. The longest survival was seen in the FDC1 group, the shortest in the FDC3 group, the FDC2 group being intermediate (P = 0.0025). FDC status was a discriminating prognostic factor for all patients, and within various age and stage categories. Combining the FDC status and the NSI-NSII grading defined the best survival group as FDC1-NSI.

CONCLUSIONS

Assessment of FDC pattern, associated with histological subtyping, brings valuable data for predicting survival and outcome in NSHD.

Human herpesvirus type 7 in Hodgkin's disease

Several lines of evidence have pointed to the involvement of a viral agent in the pathogenesis of Hodgkin's disease (HD). Therefore we investigated the presence of human herpesvirus type 7 (HHV-7) in 53 cases of HD by polymerase chain reaction (PCR), DNA in situ hybridization (ISH) and immunohistochemistry. HHV-7 DNA was frequently detected (68% of the cases) in HD biopsies by PCR independently of the histological type, whereas only 32% (P<0.05) of positive cases were found in 19 reactive lymph nodes. However, by applying the quantitative PCR technique, the majority of the samples showed a low level of viral load. Moreover, ISH for HHV-7 DNA was positive in a low number of small T lymphocytes and consistently negative in Hodgkin and Reed-Sternberg (HRS) cells, which appeared negative for HHV-7 also at immunohistochemistry. These results indicate that the high frequency of HHV-7 infection in HD: (i) is probably non-productive, (ii) mainly involves small lymphocytes belonging to the T-lineage, and (iii) is probably due to the recruitment of non-malignant reactive cells in HD tissue.

Mistaken diagnoses of Hodgkin's disease

This article reviews the frequency of and general types of diagnostic errors in Hodgkin's disease (HD) over the past several decades, discusses the most common diagnostic errors in the four histologic subtypes of HD today, and describes some of the clinical and pathologic features that may aid in avoiding a mistaken diagnosis of HD.

Pathophysiology of Hodgkin's disease: functional and molecular aspects

Hodgkin's disease (HD) is characterized by the presence of the typical, clonal malignant Hodgkin and Reed-Sternberg (H-RS) cells in a hyperplastic background of normal reactive lymphocytes, plasma cells, histiocytes, neutrophils, eosinophils and stromal cells. The neoplastic nature of HD is based on aggressive clinical progression, presence of the proliferating and atypical H-RS cells, aneuploidy and cellular clonality. Immunophenotypical studies have demonstrated frequent expression of lymphoid "activation markers' including CD15, CD25, CD30, CD40, CD54, CD70, CD71, CD80, CD86 and MHC class II and less frequent expression of T- or B-cell-associated antigens by the neoplastic H-RS cells. The clonality of H-RS cells is demonstrated by clonal EBV integration, clonal cytogenetic abnormalities including p53 mutations and clonal immunoglobulin rearrangements in some HD cases. There is involvement of diverse molecules with oncogenic potential, including presence of viruses (Epstein-Barr virus and human herpes virus-6) and/or oncogenes/tumour suppressor genes (bcl-2/bcl-x, p53/MDM-2, c-myc, c-fms, N-ras, lck). The histopathological presentation and characteristic clinical features of HD correlate with an unbalanced production of multiple cytokines and define HD as a tumour of cytokine-producing cells. The proportion of malignant H-RS cells to reactive cellular components and fibrosis is dependent on the production of particular cytokines and allows subtyping of HD cases. The combined use of immunohistochemical, biochemical and molecular techniques has thus allowed recognition that HD represents more than one clinico-pathological entity with different types of H-RS cells. The defined mechanism for the biological nature, origin and oncogenesis of H-RS cells remains not fully understood, but is susceptible to further analysis using modern technology.

Hodgkin's disease: the next decade

Although treatment of Hodgkin's disease has been extensively studied in the past, fewer clinical studies are being reported, despite the fact that the optimal therapy for each stage has not yet been established. The pathologic subtypes have not been officially changed for years, although lymphocyte-predominant disease may be unrelated to the other subtypes, lymphocyte depleted histology may really be a T-cell large-cell lymphoma, mixed cellularity represents a spectrum of disease, and some cases remain unclassifiable. Staging has also still not been completely standardized, mainly because of reliance on the lymphangiogram and the staging laparotomy, which are being less commonly performed for treatment planning. Investigators still question the value of the gallium scan, magnetic resonance imaging, and abdominal ultrasound for treatment planning, and the role of these tests in the era of managed care is not defined. Finally, because treatment for the disease is so effective, the merit of each treatment plan may eventually be weighed in terms of emotional, social, and financial costs to the patient. For patients with early-stage (I-II) disease, only limited toxicity is acceptable; for patients with bulky stage II or stage III disease, combined modality therapy must be considered standard therapy, but investigators must find ways to lessen toxicity of radiotherapy and intensive chemotherapy. Finally, for patients with stage IV disease, ongoing studies of patients at high risk of relapse may reveal which will benefit from bone marrow or peripheral stem-cell transplantation as initial therapy.

Histopathologic grading of nodular sclerosis Hodgkin's disease. Lack of prognostic significance in 254 surgically staged patients

BACKGROUND

The cellular composition of nodular sclerosis Hodgkin's disease (NS-HD) varies greatly from patient to patient. It is unclear whether subclassifying NS-HD based on cellular composition has prognostic value, because reported studies examining this issue have shown conflicting results.

METHODS

The initial pathology slides of 254 surgically staged patients with NS-HD treated at the Joint Center for Radiation Therapy were reviewed and subclassified according to British National Lymphoma Investigation criteria. The median follow-up time was 123 months.

RESULTS

A total of 211 patients were classified NS I histology (83%), and 43 patients were classified NS II (17%). There were no differences in the distribution of NS I/NS II patients by age, number of sites of disease, B symptoms, or extent of mediastinal disease. Patients with NS II disease were more likely to be male (P = 0.001), and to have pathologic Stage I-II disease (P = 0.07). The 15-year actuarial rates of disease-free survival were 77 and 80% for NS I and NS II patients, respectively (P = not significant). The 15-year overall survival rates were 87 and 93% for NS I and NS II, respectively (P = not significant). No differences were seen between NS I and NS II patients for overall or disease free survival when analyzed separately by pathologic stage or by initial treatment. Similarly, no differences between NS I and NS II patients were seen in the large subgroup of 155 pathologic stage IA-IIA patients treated with radiation therapy alone. When other histologic parameters were analyzed separately, no differences were seen in the frequency of relapse between the groups based on extent of necrosis, atypia, fibrosis, variant atypia, variant syncytia, eosinophilia, or number of mitoses.

CONCLUSIONS

The histologic subclassification of Hodgkin's disease had no prognostic significance in this group of surgically staged, uniformly treated patients.