Successful treatment of paediatric refractory Hodgkin lymphoma with immunotherapy - A case report and literature review.

AIM: To describe a rare case of primary refractory Hodgkin lymphoma nodular sclerosis syncytial variant in a child and review immunotherapy in relapsed/refractory Hodgkin lymphoma. METHODS: We described the treatment course of a child with primary refractory classic Hodgkin lymphoma and discussed different options for salvage therapy, with an emphasis on immunotherapy. We searched PubMed for all published clinical trials investigating immunotherapy in classic Hodgkin lymphoma written in English until 31 June, 2023. The reference list of each identified paper was searched for additional publications. RESULTS: Our patient was salvaged with anti-programmed cell death 1 (PD-1) antibody therapy followed by high-dose chemotherapy with autologous stem cell rescue. Radiotherapy was avoided. We identified five one-armed phase II trials investigating anti-PD-1 therapy in first relapse/refractory disease in a total of 254 patients aged 9-71 years, of which one included 31 children. The complete remission rate before high-dose chemotherapy was 59%-95% overall and 67%-89% among those with refractory disease. CONCLUSION: Although it remains to be proven in randomised trials, anti-PD-1 therapy may provide higher complete response rates than traditional chemotherapy. Anti-PD-1 therapy has the potential to increase the chance of cure while decreasing the risk of late effects from chemotherapy and radiotherapy.

Clinicopathological features of syncytial variant nodular sclerosis Hodgkin lymphoma.

The syncytial variant of nodular sclerosis Hodgkin lymphoma (SV-NSHL) is uncommon, and its clinicopathological features have not been well analyzed. In this study, we collected 142 cases of SV-NSHL. There were 76 (53.5%) males and 66 (46.5%) females with a median age of 28 years (range, 12-78); 59.9% were younger than 30 years. Patients usually presented with a mediastinal mass (97.6%) and often with bulky (35.7%) and advanced stage disease (3 or 4) (39.7%). Follow-up showed that 61.1% of patients developed relapse after standard therapy. Morphologically, the neoplasms were composed of sheets or large clusters of pleomorphic neoplastic cells with a cohesive appearance that were frequently associated with necrosis. Neutrophils and eosinophils were frequent in the background, whereas small lymphocytes were decreased. Immunohistochemical analysis showed that the following markers were frequently positive: CD30 (100%), MUM1/IRF4 (96%), PAX5 (95%), PD-L1 (91%), and CD15 (80%). CD45 was negative in all cases. Epstein-Barr virus-encoded small RNA (EBER) was detected in 19% of cases. In this cohort, age above 30 years (P = .0430), presence of B-type symptoms (P = .0394), elevated serum lactate dehydrogenase level (P = .0004), and disease relapse (P = .0108) were associated with a poorer overall survival. In contrast, patients with EBER-positive neoplasms had a better survival (P = .0418). Compared with a control group of non-SV-NSHL patients, patients with SV-NSHL were associated with a poorer overall survival (P = .011). These data suggest that SV morphology is associated with a poorer prognosis in patients treated with traditional standard-of-care therapy for classic Hodgkin lymphoma.

Syncytial variant of nodular sclerosis Hodgkin lymphoma: an under-emphasized variant.

Syncytial variant nodular sclerosis Hodgkin lymphoma (HL) is a variant that was described over 40 years ago but has received relatively little attention in the literature. Earlier studies emphasized the predominance of Hodgkin (also known as lacunar) and Reed-Sternberg (HRS) cells in this variant. Here we emphasize that the HRS cells in syncytial variant nodular sclerosis HL have a cohesive appearance, form confluent sheets, and have an immunophenotype typical of classic HL. Cases of syncytial variant nodular sclerosis HL are also commonly associated with necrosis and granulocytes in the background. Patients with syncytial variant nodular sclerosis HL tend to be young adults who present with lymphadenopathy (most often cervical) and/or a mediastinal mass. The few studies of syncytial variant nodular sclerosis HL available in the literature have suggested that this variant is associated with a higher frequency of B-type symptoms and advanced-stage disease, and one study has suggested that patients have a shorter progression-free survival than patients with typical nodular sclerosis HL. However, currently patients with syncytial variant nodular sclerosis HL are treated similarly to patients with typical nodular sclerosis HL. The large number of neoplastic cells in syncytial variant nodular sclerosis HL cases presents a diagnostic challenge, and the differential diagnosis includes non-Hodgkin lymphomas, other types of classic HL, gray zone lymphoma, thymoma and metastatic neoplasms to the mediastinum including germ cell tumors, carcinomas, and melanoma.

Syncytial variant of classic Hodgkin lymphoma: Four cases diagnosed with the aid of CD274/programmed cell death ligand 1 immunohistochemistry.

Although several reports have highlighted neoplastic PD-L1 (nPD-L1) expression in classic Hodgkin lymphoma (CHL), some have addressed associations between its expression and detailed histopathologic features. Here we describe four cases of syncytial variant of CHL (SV-CHL), with and without Epstein-Barr virus (EBV) association, and highlight the diagnostic utility of PD-L1 (clone SP142) immunohistochemistry. The patients were a 61-year-old male, 45-year-old male, 85-year-old female, and 89-year-old female. All presented with cervical or axillary lymphadenopathy, which on biopsy had the established histopathologic features of SV-CHL with a biphasic pattern of cohesive sheets of large tumor cells and typically scattered distribution of Hodgkin and Reed-Stenberg (HRS) cells. These tumor cells showed identical immunophenotypic findings for CD15, CD30, Fascin, PAX5, OCT2, BOB1 and EBV harboring, regardless of location. The exception was absent or decreased expression of nPD-L1 from tumor cells in the confluent sheets, contrasting with HRS cell positivity in typical areas of CHL. These findings offer the first suggestion of possible downregulation of nPD-L1 expression in association with the histopathologic progression of CHL. The results may be relevant for recognizing 'confluent' sheets in the diagnostic workup for SV-CHL.

Syncytial variant of nodular sclerosing Hodgkin lymphoma in children: A prognostic factor?

Nodular sclerosing Hodgkin lymphoma (HL) has an excellent prognosis in children. The syncytial variant (SV) of HL in adults represents a clinic pathologic entity with a worse outcome. We report the clinical features and the course of the disease of three children with refractory HL. The three patients with SV were analyzed in a retrospective multi-institutional study conducted in Israel in 51 children diagnosed with refractory or recurrent HL between 1997 and 2014. All the three children developed multiple recurrences soon after diagnosis. All three received at least three different chemotherapy combinations with autologous bone marrow transplantation for two patients, allogenic bone marrow transplantation in one, and immunotherapy in one. One patient died of disease, one is in complete response of the disease but developed a second metastatic malignancy, and one is alive without disease. This retrospective study shows that SV histology may be a prognostic factor for poor outcome in children diagnosed with HL.

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.