Genetic and phenotypic characterisation of HIV-associated aggressive B-cell non-Hodgkin lymphomas, which do not occur specifically in this population: diagnostic and prognostic implications

The frequency of aggressive subtypes of B-cell non-Hodgkin lymphoma (B-NHL), such as high-grade B-cell lymphomas (HGBL) with MYC and BCL2 and/or BCL6 rearrangement (HGBL-DH/TH) or Burkitt-like lymphoma (BL) with 11q aberration, is not well known in the HIV setting. We aimed to characterise HIV-associated aggressive B-NHL according to the 2017 WHO criteria, and to identify genotypic and phenotypic features with prognostic impact. Seventy-five HIV-associated aggressive B-NHL were studied by immunohistochemistry (CD10, BCL2, BCL6, MUM1, MYC, and CD30), EBV-encoded RNAs (EBERs), and fluorescence in situ hybridisation (FISH) to evaluate the status of the MYC, BCL2, and BCL6 genes and chromosome 11q. The 2017 WHO classification criteria and the Hans algorithm, for the cell-of-origin classification of diffuse large B-cell lymphomas (DLBCL), were applied. In DLBCL cases, the frequencies of MYC and BCL6 rearrangements (14.9 and 27.7%, respectively) were similar to those described in HIV-negative patients, but BCL2 rearrangements were infrequent (4.3%). MYC expression was identified in 23.4% of DLBCL cases, and coexpression of MYC and BCL2 in 13.0%, which was associated with a worse prognosis. As for BL cases, the expression of MUM1 (30.4%) conferred a worse prognosis. Finally, the prevalence of HGBL-DH/TH and BL-like with 11q aberration are reported in the HIV setting. The phenotypic and genotypic characteristics of HIV-associated aggressive B-NHL are similar to those of the general population, except for the low frequency of BCL2 rearrangements in DLBCL. MYC and BCL2 coexpression in DLBCL, and MUM-1 expression in BL, have a negative prognostic impact on HIV-infected individuals.

HHV8-negative primary effusion-based large B-cell lymphoma in a patient with chronic myeloid leukemia, BCR::ABL1-positive under dasatinib treatment: Report of a new case and literature review

Dasatinib, a second-generation tyrosine kinase inhibitor (TKI), used as treatment for chronic myeloid leukemia, BCR::ABL1-positive (CML), is complicated by pleural or pericardial effusions in about one-third of patients. Besides, in exceptional instances, effusion-based neoplastic B-cell lymphoproliferations have been described. Here, we report an HHV8-negative, EBV-positive large B-cell lymphoma presenting as a pericardial effusion in a patient with CML treated with dasatinib for 23 months, without associated tumor mass or lymphadenopathies. Large tumor cells showed a B-cell phenotype (CD20+, CD79+), with evidence of EBV infection (EBER-ISH+), but HHV8 (LANA-1) negative. Monoclonal IG gene rearrangements were identified. BCL2, BCL6, and MYC genes were not rearranged. Despite the aggressive cytomorphology the patient was in complete remission after 4 cycles of R-CHOP after 8 months follow-up. Four other cases of large B-cell effusion-based lymphomas developed in the setting of dasatinib therapy for CML have been reported in the literature. The four cases were HHV8-negative and one case was EBV-positive. Three of the four patients experienced a benign clinical course, which is in contrast to HHV8-positive primary effusion lymphoma (PEL). The mechanisms of development of these effusion-based B-cell lymphoproliferations in patients receiving TKI are not completely elucidated. Acute or relapsing effusions during TKI treatment in the setting of CML should be cytologically examined to exclude clonal B-cell lymphoproliferations.

HPV-negative Penile Intraepithelial Neoplasia (PeIN) With Basaloid Features

Most human papillomavirus (HPV)-independent penile squamous cell carcinomas (PSCCs) originate from an intraepithelial precursor called differentiated penile intraepithelial neoplasia, characterized by atypia limited to the basal layer with marked superficial maturation. Previous studies in vulvar cancer, which has a similar dual etiopathogenesis, have shown that about one fifth of HPV-independent precursors are morphologically indistinguishable from high-grade squamous intraepithelial lesions (HSILs), the precursor of HPV-asssociated carcinomas. However, such lesions have not been described in PSCC. From 2000 to 2021, 55 surgical specimens of PSCC were identified. In all cases, thorough morphologic evaluation, HPV DNA detection, and p16, p53, and Ki-67 immunohistochemical (IHC) staining was performed. HPV-independent status was assigned based on both negative results for p16 IHC and HPV DNA. Thirty-six of the 55 PSCC (65%) were HPV-independent. An intraepithelial precursor was identified in 26/36 cases (72%). Five of them (19%) had basaloid features, morphologically indistinguishable from HPV-associated HSIL. The median age of the 5 patients was 74 years (range: 67 to 83 y). All 5 cases were p16 and DNA HPV-negative. Immunohistochemically, 3 cases showed an abnormal p53 pattern, and 2 showed wild-type p53 staining. The associated invasive carcinoma was basaloid in 4 cases and the usual (keratinizing) type in 1. In conclusion, a small proportion of HPV-independent PSCC may arise on adjacent intraepithelial lesions morphologically identical to HPV-associated HSIL. This unusual histologic pattern has not been previously characterized in detail in PSCC. p16 IHC is a valuable tool to identify these lesions and differentiate them from HPV-associated HSIL.

Synchronous or collision solid neoplasms and lymphomas: A systematic review of 308 case reports

BACKGROUND

The presence of a lymphoma associated with a solid synchronous neoplasm or collision neoplasm has been rarely in the literature, and a detailed characterization of these cases is lacking to date.

OBJECTIVE

To describe the main clinicopathological features of synchronous/collision tumors.

METHODS

A systematic search in PubMed, Scielo, and Virtual Health Library literature databases for cases or case series of synchronous or collision lymphoma and other solid neoplasms reported up to March 2021 was performed. Three reviewers independently screened the literature, extracted data, and assessed the quality of the included studies. The systematic review was performed following the Preferred Reporting Items for Systematic Meta-Analyses guidelines.

RESULTS

Mean age of patients was 62.9 years (52.9% men). A total of 308 cases were included (62% synchronous and 38% collision). The most frequent location of both synchronous and collision tumors was the gastrointestinal tract with the most common solid neoplasm being adenocarcinoma, and the most frequent lymphoma diffuse large B-cell lymphoma (21.7%) and mucosa-associated lymphoid tissue lymphoma (20.4%). Of the total number of mucosa-associated lymphoid tissue lymphomas and gastric adenocarcinomas, the presence of Helicobacter pylori infection was documented in 47.3% of them. Only 2% of all cases had a previous history of lymphoma. Thus, in most cases (98%), lymphoma was discovery incidentally. In addition, nodal lymphoma was associated with metastasis in 29 (9.4%) cases as collision tumor, most commonly (90%) in locoregional lymph nodes of the solid neoplasm.

CONCLUSIONS

The frequent association of some type of B-cell lymphoma and adenocarcinoma in synchronous/collision tumors of the gastrointestinal tract points to common pathogenic mechanisms in both neoplasia, particularly related to chronic inflammation in this location. In most cases, lymphoma identified in locoregional lymph nodes or distant of a carcinoma seems to represent an incidental finding during the carcinoma diagnostic/therapeutic approach. A synergy between carcinoma and lymphoma (involving inflammation and immunosuppression mechanisms) may favor tumor progression and dissemination. A better understating of the interactions lymphoma/carcinoma in the setting of synchronous/collision tumors may help to improve patient management and prognosis.

Monomorphic epitheliotropic intestinal T-cell lymphoma comprises morphologic and genomic heterogeneity impacting outcome

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare aggressive T-cell lymphoma most reported in Asia. We performed a comprehensive clinical, pathological and genomic study of 71 European MEITL patients (36 males, 35 females, median age 67 years). The majority presented with gastrointestinal involvement and had emergency surgery, and 40% had stage IV disease. The tumors were morphologically classified into two groups: typical (58%) and atypical (i.e., non-monomorphic or with necrosis, angiotropism or starry-sky pattern) (42%), sharing a homogeneous immunophenotypic profile (CD3+ [98%] CD4- [94%] CD5- [97%] CD7+ [97%] CD8+ [90%] CD56+ [86%] CD103+ [80%] cytotoxic marker+ [98%]) with more frequent expression of TCRgd (50%) than TCRab (32%). MYC expression (30% of cases) partly reflecting MYC gene locus alterations, correlated with non-monomorphic cytology. Almost all cases (97%) harbored deleterious mutation(s) and/or deletion of the SETD2 gene and 90% had defective H3K36 trimethylation. Other frequently mutated genes were STAT5B (57%), JAK3 (50%), TP53 (35%), JAK1 (12.5%), BCOR and ATM (11%). Both TP53 mutations and MYC expression correlated with atypical morphology. The median overall survival (OS) of 63 patients (43/63 only received chemotherapy after initial surgery) was 7.8 months. Multivariate analysis found a strong negative impact on outcome of MYC expression, TP53 mutation, STAT5B mutation and poor performance status while aberrant B-cell marker expression (20% of cases) correlated with better survival. In conclusion, MEITL is an aggressive disease with resistance to conventional therapy, predominantly characterized by driver gene alterations deregulating histone methylation and JAK/STAT signaling and encompasses genetic and morphologic variants associated with very high clinical risk.

EBV-positive large B-cell lymphoma with an unusual intravascular presentation and associated haemophagocytic syndrome in an HIV-positive patient: report of a case expanding the spectrum of EBV-positive immunodeficiency-associated lymphoproliferative disorders

Intravascular large B-cell lymphoma is a rare and aggressive EBV-negative large B-cell lymphoma with a dismal outcome. Here, we describe the case of a 76-year-old HIV-positive patient with an acute presentation of systemic symptoms and rapidly fatal outcome. Autopsy revealed a disseminated large B-cell lymphoma with an intravascular distribution involving the liver, lymph nodes, spleen, and bone marrow and associated to fibrin thrombi in hepatic capillary haemangiomas. The neoplastic B cells (CD79a + / − , CD20 + / − , CD30 + , MUM1 + , PD-L1 +) showed a Hodgkin and Reed-Sternberg-like morphology and were EBV-positive with a latency type II (LMP1 + , EBNA2-). Haemophagocytosis was documented in the bone marrow and lymph nodes. This case illustrates the diagnostic challenges of large B-cell lymphoma with intravascular presentation. We found only five other cases of EBV-positive large B-cell lymphoma with an intravascular presentation in the literature, three of which had an underlying immunodeficiency adding to the broad spectrum of EBV-associated lymphoma in the setting of immunosuppression.

Patterns of change in treatment, response, and outcome in patients with follicular lymphoma over the last four decades: a single-center experience

Although the introduction of immunotherapy has improved outcomes for follicular lymphoma (FL) patients, histological transformation (HT) and early relapse still confer a poor prognosis. We sought to describe the patterns of change in treatment, response, and outcome of FL patients at our institution over the last four decades. Seven hundred and twenty-seven patients (389 F/338 M; median age, 57 years) consecutively diagnosed with grade 1-3a FL between 1980 and 2017, categorized into four decades according to the time of diagnosis, constituted the study population. Clinical characteristics, treatment, response, absolute and relative survival, HT, second malignancies (SM), and causes of death were assessed. Median OS for the entire cohort was 17.6 years. From decade 1 to 4, there was an increase in the complete response rate (48 to 70%), progression-free survival (40 to 56% at 5 years), OS (77 to 86% at 5 years), and relative survival ratio (0.83 to 0.94 at 5 years), with no significant differences in the risk of HT or SM. Lymphoma remained the most common cause of death in all four decades. These findings illustrate the overall improvement in outcome for FL patients, but support the need for further research into risk stratification and management.

Reproducibility of histologic prognostic parameters for mantle cell lymphoma: cytology, Ki67, p53 and SOX11

Mantle cell lymphoma (MCL) shows a clinical aggressiveness that varies from patient to patient. Despite major advances in outcomes with current immunochemotherapy, the future development of therapies requires risk stratification to tailor therapy intensity. Within the group of reference pathologists for the ongoing trials of the European MCL Network, we performed a round robin test on a tissue microarray to evaluate the reproducibility in assessing the biomarkers of outcome in MCL. Cytological subtype, Ki67-index and expression of p53 and SOX11 were evaluated on 20 diagnostic tumour samples by eight participating labs independently. We demonstrate that the assessment of the proliferation index by counting the Ki67 positive cells as well as assessment of SOX11 and p53 expression status is reproducible between labs. For the most established prognostic biomarker, Ki67, the intra-class correlation coefficient was very good when assessed as a continuous parameter (0.87). The agreement was lower when the values were analysed in a dichotomized way applying the commonly used cutoff of 30% (kappa = 0.65, complete concordance of all labs in 13/20 (65%)). Cases with discrepant results between labs in the dichotomized analysis showed mean values close to the cutoff of 30%. Centralised scoring and digital image analysis revealed results in line with the scores from individual labs. All cases in our cohort were additionally assessed for gene expression signatures and of TP53 gene alterations. Given the good reproducibility when guidelines of assessment are applied, the biomarker studied in this inter-laboratory test presents potential candidates to be enhanced for risk-stratification in the future clinical trials.

Clinicopathological evaluation of the programmed cell death 1 (PD1)/programmed cell death-ligand 1 (PD-L1) axis in post-transplant lymphoproliferative disorders: association with Epstein-Barr virus, PD-L1 copy number alterations, and outcome

AIMS

The clinical implications of the programmed cell death 1 (PD1)/programmed cell death-ligand 1 (PD-L1) axis in patients with post-transplant lymphoproliferative disorders are largely unknown, and its association with Epstein-Barr virus (EBV) status and PD-L1 copy number alterations (CNAs) has not been thoroughly studied.

METHODS AND RESULTS

PD1/PD-L1 expression was studied in 50 adult post-transplant lymphoproliferative disorders, and the correlations with PD-L1 CNAs, EBV, clinicopathological features and outcome were evaluated. Thirty-seven (74%) cases were classified as diffuse large B-cell lymphoma (DLBCL), nine (18%) cases were classified as polymorphic, and four (8%) cases were classified as classic Hodgkin lymphoma. Thirty-four cases were EBV-positive, with 29 of 34 (85%) having latency II or III, and 15 of 34 (44%) having viral replication. PD-L1 expression in tumour cells and tumour-associated macrophages was observed in 30 (60%) and 37 (74%) cases, respectively. PD1 positivity was seen in 16 (32%) cases. PD-L1 expression was associated with EBV with latency II or III (P = 0.001) and organ rejection (P = 0.04), and, in DLBCL, with non-germinal centre type DLBCL (P < 0.001). Cases with PD-L1-positive tumour cells showed a higher number of PD-L1 CNAs than PD-L1-negative cases (P = 0.001). Patients with EBV/latency III/replication and simultaneous PD-L1 expression showed the worst overall survival (P < 0.001).

CONCLUSIONS

The PD1/PD-L1 axis is deregulated in post-transplant lymphoproliferative disorders, with frequent PD-L1 expression and PD1 negativity. PD-L1 expression is associated with EBV latency II or III and PD-L1 CNAs, and probably reflects a proinflammatory tumour microenvironment. The combined analysis of EBV status and PD-L1 expression may help to identify deeply immunosuppressed patients who can benefit from immune reconstitution approaches.