Primary testicular lymphoma

Testicular FDG Uptake on PET/CT in Patients with Lymphoma: Correlation with Age

The purpose of this observational study was to investigate whether the standard uptake value (SUV) measurement has practical utility in distinguishing secondary testicular involvement from physiologic uptake in patients with lymphoma. A Radiology Information System (RIS) search was conducted for all PET/CT studies performed from 2010-2016 on adult male patients with a diagnosis of lymphoma. Patients with clinical or pathologic diagnosis of testicular lymphoma were excluded to undergo a separate analysis. PET/CT images of 606 patients with 1087 scans, in which 2045 testes were included in the field of view, were reviewed and measurements were performed for standardized uptake values of both testicles (SUV_max) as well as of the liver (SUV_max and SUV_mean). The mean SUV_max of the testicles was 3.75 ± 0.90 (range 1.16-8.38). The mean ratio of testis SUV_max / liver SUV_mean (T/L) was 1.78 ± 0.43. Trends in SUV_max and age were significant for a negative correlation by a small magnitude of 0.066 per 10 years (P < 0.001). T/L had similar changes with significant low magnitude decrease with increasing age (0.059 per 10-year increase, P < 0.001). In our separate analysis of 3 patients with clinical or pathology proven testicular lymphoma, the average pathologic SUV_max was 13.47 (range 11.39-15.97). This study has the largest known sample size for quantifying physiologic uptake in the testes. SUV measurements to quantify F-18 Fluorodeoxyglucose (FDG) uptake on PET/CT likely have practical utility in discriminating between physiologic and pathologic uptake of FDG in cases of secondary testicular lymphoma.

[Diagnosis and treatment of rare testicular tumors using the example of malignant mesothelioma of the tunica vaginalis testis and Sertoli cell tumors]

BACKGROUND

Rare tumors of the testis not originating from germinal epithelium are a diagnostic and therapeutic challenge.

OBJECTIVES

To present current approaches in rare tumors of the testis using the examples of Sertoli cell tumor (SCT) and malignant mesothelioma of the tunica vaginal testis (MMTVT).

METHODS

A literature search in PubMed and the abstract databases of ASCO and ESMO was performed. Articles and book chapters were selected based on relevance to everyday treatment.

RESULTS

The low incidence of testicular tumors not originating from the germinal epithelium makes a standardized approach difficult. Diagnosis and treatment depend on the underlying diagnosis. While most SCT are benign, malignant subtypes require extensive resection including metastatic surgery if complete resection is possible. In MMTVT, multimodality treatment concepts are followed, according to the malignant mesotheliomas of the pleura.

CONCLUSION

Systematic registration of rare testicular tumors and comprehensive molecular pathological analysis are urgently needed to improve the understanding of tumor biology and to develop new therapeutic strategies.

Molecular classification of aggressive lymphomas-past, present, future

Aggressive large B-cell lymphomas (LBCLs) represent a frequent but clinically and molecularly heterogeneous group of tumors. Technological advances over the last decades prompted the development of different classification schemas to either sharpen diagnoses, dissect molecular heterogeneity, predict outcome, or identify rational treatment targets. Despite increased diagnostic precision and a noticeably improved molecular understanding of these lymphomas, clinical perspectives of patients largely remain unchanged. Recently, finished comprehensive genomic studies discovered genetically defined LBCL subtypes that predict outcome, provide insight into lymphomagenesis, and suggest rational therapies with the hope of generating patient-tailored treatments with increased perspective for patients in greatest need. Current and future efforts integrate multiomics studies and/or leverage single-cell technologies and will provide us with an even more fine-grained picture of LBCL biology. Here, we highlight examples of how high-throughput technologies aided in a better molecular understanding of LBCLs and provide examples of how to select rationally designed targeted treatment approaches that might personalize LBCL treatment and eventually improve patients' perspective in the near future.

Twenty-year Experience with Genitourinary Lymphoma at a Community Hospital

Introduction: Non-Hodgkin lymphoma is the seventh most common cancer in the United States. It may involve any extranodal organ, although involvement of the genitourinary (GU) tract accounts for <5% of all primary extranodal lymphomas. Published GU lymphoma literature is currently limited to small case series and case reports. The last substantial American series was published in 2009. Our objective was to characterize cases of GU lymphoma from our institution based on organ involved and to review relevant literature.Patients and Methods: After institutional review board approval, we retrospectively reviewed medical records of patients diagnosed with lymphoma involving the GU organs from 1995 through 2015. Patients with obstructive uropathy from retroperitoneal adenopathy without parenchymal involvement of a GU organ were excluded. We classified extranodal GU lymphomas as primary or secondary, based on involvement of other organs and distant lymphadenopathy.Results: Thirty-six patients had lymphoid neoplasms involving the kidney, ureters, bladder, testis, penile skin, or prostate in our health system during the study period. Of these, 15 (41.6%) were primary. Most patients initially sought consultation for GU-related symptoms, such as bladder obstruction, hematuria, testicular mass, or abdominal pain. Histological subtypes and flow cytometry findings varied broadly.Conclusion: Our series reports site-specific outcomes data and adds detail to findings from other published series. Although GU lymphomas are rare, our series confirms prior studies demonstrating presentation in urologic organs. They should be considered in the differential diagnosis in all patients, especially those with unusual findings on examination, cystoscopy, or computed tomography scan.

A case at crossroads-urological presentation, cardiac complication and haematological diagnosis: should imaging be pursued prior to orchidectomy at all costs?

This case report explores the interesting case of a 71-year-old gentleman who presented with a testicular lump following trauma. Ultrasound imaging of the testicle demonstrated malignancy and subsequently orchidectomy was listed. Due to a scheduling difficulty, this was prioritized ahead of his whole-body computed tomography scan. Intraoperatively, he developed electrocardiogram changes suggestive of a non-ST elevated myocardial infarction. Post-operative imaging demonstrated a diffuse large B-cell lymphoma encroaching the heart and greater vessels. This case report highlights the importance of preoperative imaging, even where it may prove challenging. We assess the adequacy of current guidelines within the UK on imaging for new testicular malignancies.

Radiotherapy for Non-Hodgkin Lymphomas

Radiotherapy (RT) plays a diverse and essential role in the contemporary management of non-Hodgkin lymphoma (NHL) and remains the single most powerful monotherapeutic intervention for both aggressive and indolent subtypes. Over the past decade, there have been significant advancements in radiation oncology practice, which have made modern treatments safer and more conformal. Despite this sophistication and evidence supporting a continued role for RT, numerous data suggest that utilization is on the decline. In this review, we discuss the rationale for RT in 4 commonly encountered scenarios: combined modality therapy for limited-stage aggressive NHL, consolidation therapy for advanced-stage aggressive NHL, and the changing roles of salvage RT for relapsed/refractory NHL in an era of new frontiers such as cellular therapies. We also evaluate current strategies to treat indolent histologies. We conclude with perspectives on how RT for the hematological malignancies may continue to evolve.

Different chemokine profile between systemic and testicular diffuse large B-cell lymphoma

Although treatment for diffuse large B-cell lymphoma (DLBCL) has taken some notable steps in the 2000s, there are still subgroups of patients suffering from high mortality and relapse rates. To further improve treatment outcomes, it is essential to discover new mechanisms of chemotherapy resistance and create new treatment approaches to overcome them. In the present study, we analyzed the expression of chemokines and their ligands in systemic and testicular DLBCL. From our biopsy sample set of 21 testicular and 28 systemic lymphomas, we were able to demonstrate chemokine profile differences and identify associations with clinical risk factors. High cytoplasmic CXCL13 expression had correlations with better treatment response, lower disease-related mortality, and limited stage. This study suggests that active CXCR5/CXCL13 signaling could overtake the CXCR4/CXCL12 axis, resulting in a better prognosis.

Radical inguinal orchidectomy: the gold standard for initial management of testicular cancer

Radical inguinal orchidectomy with division of the spermatic cord at the internal inguinal ring is the gold standard for diagnosis and local treatment of testicular malignancies. The technique is well established and described in detail in this paper, collating methods from various surgical textbooks and articles. We also discuss pre-operative considerations including fertility counselling and potential testicular prosthesis at time of orchidectomy, and the importance of contemplating differential diagnoses such as para-testicular sarcoma and primary testicular lymphoma (PTL) prior to performing radical orchidectomy (RO). The evidence and indications for new surgical techniques to treat local testicular malignancies are also described, including testis sparing surgery (TSS) and spermatic cord sparing orchidectomy.

Recent malignant testicular tumor trend in Japan, a country with an aging population: a large-scale study of 2012-2015 hospital-based cancer registry data

OBJECTIVE

Japan's national database of hospital-based cancer registries is estimated to cover ~67% of all new cancer cases. Using this database, we analyzed the characteristics of the recently diagnosed testicular malignancy.

METHODS

We obtained data for 6510 adult testicular malignancy patients diagnosed in 2012-2015. The distributions of patient ages, histological diagnoses and testicular germ cell tumor hospital care volumes were determined.

RESULTS

The most common histology was seminoma (60.3% of all testicular malignancies), followed by non-seminoma (24.1%) and diffuse large B-cell lymphoma (13.1%). The median and mean ages of the testicular germ cell tumor patients were high at 38 and 39.8 years, respectively. The age distribution peaked at 30-40 years, followed by 40-50 years. Approximately 18% of testicular germ cell tumor patients were ≥50 years. The ages of the diffuse large B-cell lymphoma patients peaked at 70-80 years (mean 67.7 years). When the analysis was limited to the testicular germ cell tumor patients who received first-course cancer treatment at the participating hospitals, the number of high-volume hospitals with ≥20 testicular germ cell tumor care volume was limited to 61 (10.0% of the 605 hospitals that treated ≥1 testicular germ cell tumor patient). However, when the patients who changed hospitals during treatment or relapsed after treatment completion were analyzed together, the number of high-volume hospitals increased to 104 (17.0% of 612 hospitals).

CONCLUSION

The testicular germ cell tumor patients' mean age was nearly 40 years. The proportions of older testicular germ cell tumor patients and diffuse large B-cell lymphoma patients were higher than previously thought. The reasons for this trend are unknown, but it is important to address the trend identified herein in a country with a super-aging population.

Current Clinical Applications and Future Perspectives of Immune Checkpoint Inhibitors in Non-Hodgkin Lymphoma

Cancer cells escape immune recognition by exploiting the programmed cell-death protein 1 (PD-1)/programmed cell-death 1 ligand 1 (PD-L1) immune checkpoint axis. Immune checkpoint inhibitors that target PD-1/PD-L1 unleash the properties of effector T cells that are licensed to kill cancer cells. Immune checkpoint blockade has dramatically changed the treatment landscape of many cancers. Following the cancer paradigm, preliminary results of clinical trials in lymphoma have demonstrated that immune checkpoint inhibitors induce remarkable responses in specific subtypes, most notably classical Hodgkin lymphoma and primary mediastinal B-cell lymphoma, while in other subtypes, the results vary considerably, from promising to disappointing. Lymphomas that respond to immune checkpoint inhibitors tend to exhibit tumor cells that reside in a T-cell-rich immune microenvironment and display constitutive transcriptional upregulation of genes that facilitate innate immune resistance, such as structural variations of the PD-L1 locus, collectively referred to as T-cell-inflamed lymphomas, while those lacking such characteristics are referred to as noninflamed lymphomas. This distinction is not necessarily a sine qua non of response to immune checkpoint inhibitors, but rather a framework to move the field forward with a more rational approach. In this article, we provide insights on our current understanding of the biological mechanisms of immune checkpoint evasion in specific subtypes of B-cell and T-cell non-Hodgkin lymphomas and summarize the clinical experience of using inhibitors that target immune checkpoints in these subtypes. We also discuss the phenomenon of hyperprogression in T-cell lymphomas, related to the use of such inhibitors when T cells themselves are the target cells, and consider future approaches to refine clinical trials with immune checkpoint inhibitors in non-Hodgkin lymphomas.

Rare Tumours of the Testis: Twelve Years of Experience

Rare tumours of the testis includes a wide variety of tumours. We aim to present clinical and histological characteristics of our patients with rare tumours of the testis. The medical records of 33 patients who were treated and followed-up for testicular rare tumours in our center between 2007 and 2020 were retrospectively reviewed. Of all the 243 testicular tumours, 222 cases (91.4%) were germ cell tumours and 21 cases (8.6%) were non-germ cell tumours. Thirty-three rare tumours of the testis including rare germ cell tumours and non-germ cell tumours were detected. The mean age of the patients at diagnosis was 34 years (range 18-68 years). The histological types of rare testicular tumours were as follows: teratoma 4.5% (n=11), sex-cord stromal tumours 4.5% (n=11), paratesticular tumours 3.2% (n=8), and the others [lymphoma 0.4% (n=1), mesothelioma 0.4% (n=1) and choriocarcinoma 0.4% (n=1)]. The median duration of follow-up was 32 months (range 1 to 256 months). None of the patients with non-metastatic disease stage developed recurrence after having received appropriate therapy. Metastatic disease was documented in 9 cases at the time of diagnosis (five patients with teratomas, two patients with Leydig cell tumour, one patient with choriocarcinoma and rhabdomyosarcoma). The most common subtypes of testicular rare tumours in our center was teratoma and sex-cord stromal tumours. Because of testicular rare tumours have different biological features and different clinical outcomes, the management of each tumour requires a different approach.

Primary lymphomas of the genitourinary tract: A population-based study

OBJECTIVE

We performed a population-based analysis focusing on primary extranodal lymphoma of either testis, kidney, bladder or prostate (PGUL).

METHODS

We identified all cases of localized testis, renal, bladder and prostate primary lymphomas (PL) versus primary testis, kidney, bladder and prostate cancers within the Surveillance, Epidemiology, and End Results database (1998-2015). Estimated annual proportion change methodology (EAPC), multivariable logistic regression models, cumulative incidence plots and multivariable competing risks regression models were used.

RESULTS

The rates of testis-PL, renal-PL, bladder-PL and prostate-PL were 3.04%, 0.22%, 0.18% and 0.01%, respectively. Patients with PGUL were older and more frequently Caucasian. Annual rates significantly decreased for renal-PL (EAPC: -5.6%; p=0.004) and prostate-PL (EAPC: -3.6%; p=0.03). In multivariable logistic regression models, older ager independently predicted testis-PL (odds ratio [OR]: 16.4; p<0.001) and renal-PL (OR: 3.5; p<0.001), while female gender independently predicted bladder-PL (OR: 5.5; p<0.001). In surgically treated patients, cumulative incidence plots showed significantly higher 10-year cancer-specific mortality (CSM) rates for testis-PL, renal-PL and prostate-PL versus their primary genitourinary tumors. In multivariable competing risks regression models, only testis-PL (hazard ratio [HR]: 16.7; p<0.001) and renal-PL (HR: 2.52; p<0.001) independently predicted higher CSM rates.

CONCLUSION

PGUL rates are extremely low and on the decrease in kidney and prostate but stable in testis and bladder. Relative to primary genitourinary tumors, PGUL are associated with worse CSM for testis-PL and renal-PL but not for bladder-PL and prostate-PL, even after adjustment for other-cause mortality.

Adverse prognostic impact of regulatory T-cells in testicular diffuse large B-cell lymphoma

OBJECTIVES

Testicular diffuse large B-cell lymphoma (T-DLBCL) is a rare and aggressive extranodal lymphoma. We have previously shown that high content of tumor-infiltrating lymphocytes (TILs) and PD-1 expressing TILs associate with better survival in T-DLBCL. In this study, we have further characterized distinct TIL subtypes and their proportions in association with patient demographics and survival.

METHODS

We used multiplex immunohistochemistry to characterize TIL phenotypes, including cytotoxic T-cells (CTLs; CD8⁺ , OX40⁺ , Granzyme B⁺ , Ki-67⁺ , LAG-3⁺ , TIM-3⁺ , PD-1⁺ ), CD4⁺ T-cells (CD3⁺ , CD4⁺ , TIM-3⁺ , LAG-3⁺ ), regulatory T-cells (Tregs; CD3⁺ , CD4⁺ , FoxP3⁺ ), and T helper 1 cells (Th1; CD3⁺ , CD4⁺ , T-bet⁺ ) in 79 T-DLBCLs, and correlated the findings with patient demographics and outcome.

RESULTS

We observed a substantial variation in TIL phenotypes between the patients. The most prominent CD8⁺ TILs were Ki-67⁺ and TIM-3⁺ CTLs, whereas the most prominent CD4⁺ TILs were FoxP3⁺ Tregs. Despite the overall favorable prognostic impact of high TIL content, we found a subpopulation of T-bet⁺ FoxP3⁺ Tregs that had a significant adverse impact on survival. Lower content of CTLs with activated or exhausted phenotypes correlated with aggressive clinical features.

CONCLUSIONS

Our results demonstrate significant variation in TIL phenotypes and emphasize the adverse prognostic impact of Tregs in T-DLBCL.

Metachronous extranodal natural killer/T-cell lymphoma of nasal type and primary testicular lymphoma

We report a rare case of metachronous lymphoma with two distinct cell lineages in a 75-year-old man. The patient complained about having nasal obstruction for 2 years and extranodal natural killer (NK)/T-cell lymphoma of the nasal type was diagnosed from a biopsy. The immunohistochemical staining for CD56 and in situ hybridization for Epstein-Barr virus (EBV)-encoded small RNA (EBER-ISH) were positive and the tumor cells were negative for CD20. After 13 months of concurrent chemoradiotherapy, the patient presented with swelling of the left testis. Positron emission tomography scan detected an abnormal uptake in the testis. A diffuse large B-cell lymphoma, not otherwise specified, was diagnosed from subsequent radical orchiectomy. The immunohistochemical staining revealed to be positive for CD20, BCL2, BCL6, and MYC and negative for CD10 and EBER-ISH.

Molecular Classification of Large B-Cell Non-Hodgkin Lymphoma

Large B-cell lymphomas (LBCLs) represent a frequent but clinically and morphologically heterogeneous group of tumors. Technological advances over the last 2 decades prompted the development of new classification schemas to sharpen diagnoses, dissect molecular heterogeneity, and identify rational treatment targets. Despite increased molecular understanding of these lymphomas, the clinical perspectives of patients largely remain unchanged. Recently finished comprehensive genomic studies discovered genetically defined LBCL subtypes that predict outcome, provide insight into lymphomagenesis, and suggest rational therapies with the hope of generating patient-tailored treatments with increased perspective for patients in greatest need. Here, we summarize notable examples of how high-throughput technologies aided in better molecular understanding of LBCLs and provided examples of rationally designed targeted treatments.

Low Absolute Lymphocyte Counts in the Peripheral Blood Predict Inferior Survival and Improve the International Prognostic Index in Testicular Diffuse Large B-Cell Lymphoma

Low absolute lymphocyte counts (ALC) and high absolute monocyte counts (AMC) are associated with poor survival in patients with diffuse large B-cell lymphoma (DLBCL). We studied the prognostic impact of the ALC and AMC in patients with testicular DLBCL (T-DLBCL). T-DLBCL patients were searched using Southern Finland University Hospital databases and the Danish lymphoma registry. The progression free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier and Cox proportional hazards methods. We identified 178 T-DLBCL patients, of whom 78 (44%) had a low ALC at diagnosis. The ALC did not correlate with survival in the whole cohort. However, among the patients treated with rituximab (R) containing regimen, a pre-therapeutic low ALC was associated with an increased risk of progression (HR 1.976, 95% CI 1.267–3.086, p = 0.003). Conversely, intravenous (iv) CNS directed chemotherapy translated to favorable outcome. In multivariate analyses, the advantage of an iv CNS directed chemotherapy was sustained (PFS, HR 0.364, 95% CI 0.175–0.757, p = 0.007). The benefit of R and intravenous CNS directed chemotherapy was observed only in non-lymphopenic patients. The AMC did not correlate with survival. A low ALC is an adverse prognostic factor in patients with T-DLBCL. Alternative treatment options for lymphopenic patients are needed.

Imaging of scrotal masses

Testicular cancer is responsible for approximately 0.1% of all cancer deaths in the USA, and seminoma is the most common type of testicular tumor. Ultrasonography is the primary imaging modality for accessing testicular and extratesticular lesions, while magnetic resonance imaging can be used for problem solving in lesion characterization in certain cases. CT imaging is usually performed for retroperitoneal staging of testicular cancer metastasis and follow-up after treatment. Extratesticular masses are common, yet rarely malignant. Imaging plays an important role in primary diagnosis of testicular cancer and differentiating it from common non-neoplastic findings. The purpose of this article is to review various imaging findings in testicular and extratesticular masses.

Primary testicular T-lymphoblastic lymphoma in a child: A case report

RATIONALE

Primary non-Hodgkin lymphoma (NHL) of the testes is rare, representing about 9% of testicular neoplasms and 1% to 2% of non-Hodgkin lymphomas.

PATIENT CONCERNS

A previously healthy 47-month-old boy came to our institution for 3 months unilateral testicular swelling without tenderness. After preliminary examination, inguinal orchiectomy was performed to resect the right scrotal mass. The histopathological diagnosis of high-grade lymphoma was rendered and paraffin blocks were sent for immunophenotyping.

DIAGNOSIS

The final diagnosis by histopathological combined with immunohistochemical staining revealed primary testicular T-cell lymphoblastic lymphoma (St Jude Children's Research Hospital Staging System, stage I).

INTERVENTIONS

The patient was treated with right inguinal orchidectomy followed by chemotherapy (SMCC-2011 protocol modified based on the BFM-90/95 regimen from Germany) without prophylactic radiotherapy to the contralateral testis.

OUTCOMES

After 36 months of follow-up, the patient is now disease-free without any complication.

LESSONS

T-lymphoblastic lymphoma should be considered in the differential diagnosis of testicular masses in children. Intensive chemotherapy may improve the prognosis of such patients.

Combined chemotherapy and radiotherapy improves survival in 1897 testicular Lymphoma patients from a contemporary cohort

INTRODUCTION

The standard of care (SOC) for primary testicular lymphoma (PTL) is orchiectomy, chemotherapy (CHT), and radiotherapy (RT). We hypothesized that men may not receive SOC and may have worse outcomes. To assess this, we queried the National Cancer Database (NCDB) to analyze treatment patterns and survival in PTL patients.

METHODS

The NCDB was queried (2006-2016) for men diagnosed with extranodal lymphoma with primary site testis. Patients were placed in 2 treatment groups (1) orchiectomy with chemotherapy plus radiotherapy (CHT + RT), named the SOC group; and 2) CHT + orchiectomy, or RT + orchiectomy, or orchiectomy alone, grouped as non-SOC. Propensity score matching and Kaplan-Meier analysis were used to investigate 5-year overall survival (OS).

RESULTS

Two thousand two hundred thirty-two men with PTL underwent orchiectomy. After exclusions, 891 men were included in the SOC group and 1,006 men were included in the non-SOC group. KM analysis showed 5-year OS was significantly higher in the SOC group vs. non-SOC for all stages (hazard ratio = 0.54, with 95% confidence interval 0.45 to 0.65, P < 0.0001).

CONCLUSIONS

This study represents one of the largest PTL cohort reported to date reflecting current treatments and shows men receiving standard of care treatment have significantly improved survival. Additionally, analysis reveals that most men included in the NCDB do not receive the standard of care.

TBL1XR1 mutation predicts poor outcome in primary testicular diffuse large B-cell lymphoma patients

Primary testicular lymphoma (PTL), often appearing as focal masses in the scrotum and epididymides, is the most frequent testicular tumor in aged men. Although MYD88 and CD79B mutations were the most common genetic alterations observed, the gene mutation landscape of PTL remains poorly defined. In this study, we identified 1326 mutations involving 311 genes or regions in 90 PTL patients through next-generation sequencing (NGS). PTL patients with the TBL1XR1 mutation, irrespective of treatment therapy, had an inferior overall survival (OS) than TBL1XR1 WT (wild type) patients (p = 0.045). Moreover, patients with this mutation, treated with a CHOP regimen (CTX 750 mg/m² iv, d1,8 ADM 50 mg/m² iv, d1 VCR 1.4 mg/m² iv, d1 PDN 100 mg/m² po d1–5), had a poorer OS (p = 0.019). In addition, such patients were prone to have a more intensive infiltration of tumors (p = 0.025, x² = 4.890). Thus, we speculated that patients with a TBL1XR1 mutation have poorer prognosis, partly due to greater invasion and infiltration of tumors. Our results suggest that the TBL1XR1 mutation can be used as an indicator to predict the prognosis of PTL and can be employed as a promising new target for treatment of PTL in the future.

MYD88 L265P mutation and CDKN2A loss are early mutational events in primary central nervous system diffuse large B-cell lymphomas

The genetic alterations that define primary central nervous system lymphoma (PCNSL) are incompletely elucidated, and the genomic evolution from diagnosis to relapse is poorly understood. We performed whole-exome sequencing (WES) on 36 PCNSL patients and targeted MYD88 sequencing on a validation cohort of 27 PCNSL patients. We also performed WES and phylogenetic analysis of 3 matched newly diagnosed and relapsed tumor specimens and 1 synchronous intracranial and extracranial relapse. Immunohistochemistry (IHC) for programmed death-1 ligand (PD-L1) was performed on 43 patient specimens. Combined WES and targeted sequencing identified MYD88 mutation in 67% (42 of 63) of patients, CDKN2A biallelic loss in 44% (16 of 36), and CD79b mutation in 61% (22 of 36). Copy-number analysis demonstrated frequent regions of copy loss (ie, CDKN2A), with few areas of amplification. CD79b mutations were associated with improved progression-free and overall survival. We did not identify amplification at the PD-1/PD-L1 loci. IHC for PD-L1 revealed membranous expression in 30% (13 of 43) of specimens. Phylogenetic analysis of paired primary and relapsed specimens identified MYD88 mutation and CDKN2A loss as early clonal events. PCNSL is characterized by frequent mutations within the B-cell receptor and NF-κB pathways. The lack of PD-L1 amplifications, along with membranous PD-L1 expression in 30% of our cohort, suggests that PD-1/PD-L1 inhibitors may be useful in a subset of PCNSL. WES of PCNSL provides insight into the genomic landscape and evolution of this rare lymphoma subtype and potentially informs more rational treatment decisions.

De Novo Testicular Extranodal NK/T-Cell Lymphoma: A Clinicopathologic Study of 21 Cases With Review of Additional 18 Cases in the Literature

Although the testis is not uncommonly involved during the course of disease in both nasal and non-nasal extranodal NK/T-cell lymphoma (ENKTCL), only a few cases presenting initially with a testicular mass have been previously reported. These have been documented as case reports, rather than as study series. Because of its rarity, the clinicopathologic features and the prognosis of de novo testicular ENKTCL have not been well characterized. Clinicopathologic features of 21 cases of de novo testicular ENKTCL from 3 institutions in China were retrospectively analyzed with review of an additional 18 cases from the literature. De novo testicular ENKTCL accounted for 0.72% (21/2906) of all ENKTCL during the study period. The median age of patients with de novo testicular ENKTCL was 45 years (range, 21 to 79 y). Most (90.9%) cases occurred in Asians. All patients initially presented with testicular swelling and most (91.9%) had unilateral testicular masses. The majority (73.0%) of patients presented at Ann Arbor stage I/II. Expression of CD56 was found in 92.1% (35/38) of the available cases. Interestingly, aberrant expression of CD20 was found in the tumor cells in 10.3% (4/39) of cases. The majority of patients with follow-up data (24/30, 80%) had extratesticular involvement during the follow-up period (median follow-up, 6 months; range, 0.5 to 87 mo). Preferential sites of extratesticular involvement included lymph nodes, skin, contralateral testis, bone marrow, spleen, adrenal gland, and central nervous system. Of the 30 patients with survival data, 70% (22/30) of patients died of the disease. The 2-year overall survival of patients with de novo testicular ENKTCL was 23%, and the median survival was 9.5 months. Patients that presented with B symptoms showed a trend toward inferior overall survival (P=0.095). No statistical significance was found between patients with stage I/II and stage III/IV (P=0.783). De novo testicular ENKTCL tends to disseminate early, shows extremely poor outcome, and should be recognized as a highly aggressive form of ENKTCL. A portion of cases show aberrant expression of CD20, and accurate diagnosis as well as timely and optimal treatment are very important.

Lymphomas arising in immune-privileged sites: insights into biology, diagnosis, and pathogenesis

Session 2 of the 2018 European Association of Hematopathology/Society for Hematopathology Workshop focused on lymphomas arising in immune-privileged sites: both lymphomas arising in the traditionally described "immune sanctuary" sites of the central nervous system (CNS) and testes, as well as those arising at sites of local immune privilege. Primary CNS large B cell lymphoma and primary testicular large B cell lymphoma were discussed, and the biology of these unique tumors was highlighted by several cases showing the classic mutation profile including MYD88 L265P and CD79B. The tendency of these tumors to involve both the CNS and testis was also reinforced by several cases. Four cases of low-grade B cell lymphomas (LGBCL) of the CNS were discussed. Two were classic Bing-Neel syndrome associated with LPL, and two were LGBCL with plasmacytic differentiation and amyloid deposition without systemic disease. Rare examples of systemic T and NK cell lymphomas involving the CNS were also discussed. Several cases of breast implant-associated anaplastic large cell lymphoma (BI-ALCL) were submitted showing the typical clinicopathologic features. These cases were discussed along with a case with analogous features arising in a patient with a gastric band implant, as well as large B cell lymphomas arising alongside foreign materials. Finally, large B cell lymphomas arising in effusions or localized sites of chronic inflammation (fibrin-associated diffuse large B cell lymphoma [DLBCL] and DLBCL associated with chronic inflammation) were described. The pathogenesis of all of these lymphomas is believed to be related to decreased immune surveillance, either innate to the physiology of the organ or acquired at a local site.

Prevalence And Clinical Significance Of Oncogenic CD79B And MYD88 Mutations In Primary Testicular Diffuse Large B-Cell Lymphoma: A Retrospective Study In China

Purpose

In this study, we investigated the prevalence of CD79B and MYD88 mutations and their relation to clinical characteristics in a cohort of Chinese patients with primary testicular diffuse large B cell lymphoma (PT-DLBCL).

Patients and methods

We examined the mutational status of CD79B and MYD88 by Sanger sequencing, and the gene amplification and protein expression of MYD88 in tissue samples from 30 cases of PT-DLBCL by quantitative polymerase chain reaction and immunohistochemistry, respectively. Western blotting was used to analyze phosphorylated STAT3 (p-STAT3) and phosphorylated p65 (p-p65) protein expression in cell lines harboring retroviral constructs for WT MYD88 or MYD88 mutant.

Results

Immunophenotypically, MYD88 protein staining was positive in 26/30 (86.67%) cases, and 23/30 (76.7%) cases tested positive for p65 in the nucleus. Genetically, CD79B mutation was found in 13/30 (43.3%) cases, whereas the MYD88^L265P mutation was found in 18/30 (60.0%) cases. Interestingly, CD79B and MYD88 mutations were more prevalent in the non-germinal center B cell (GCB) subtype (83.3% and 76.9%, respectively) and were relatively rare in the GCB subtype (16.7% and 23.1%, respectively). Furthermore, although MYD88 was significantly amplified in PT-DLBCL, the amplification status showed no correlation with its mutational status and protein expression. Clinicopathological comparison between the mutant and wild-type group showed that both CD79B mutation and MYD88^L265P were not significantly correlated with age, anatomical site, Ann Arbor stage, non-GCB/GCB subtype, p65 protein expression, BCL-2 protein expression, or BCL-2/c-MYC double expression (P>0.05). Survival analyses showed that high IPI and advanced stage (stage III–IV) associated with worse outcome (P<0.05). The expression of p-STAT3 and p-p65 protein was upregulated in the mutant group, indicating that MYD88 mutant activated NF-κB and JAK–STAT3 signaling.

Conclusion

Our results suggest that MYD88 and CD79B mutations are important drivers of immune-privileged site-associated DLBCL and highlight potential therapeutic targets for personalized treatment.

Primary lymphomas of the intraabdominal solid organs and the gastrointestinal tract: spectrum of imaging findings with histopathological confirmation

Unlike nodal lymphoma, primary lymphomas of the intraabdominal organs are uncommon neoplasms whose diagnosis may be challenging in certain clinical circumstances. Despite this difficulty for imaging diagnosis, there are several imaging features on ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography that may suggest the correct diagnosis. The scope of this review is to describe and illustrate the imaging features of primary lymphoma of intraabdominal organs providing clues to the diagnosis, together with their pathological correlations.

Expression of programmed cell death-ligand 1 in primary testicular diffuse large B cell lymphoma: A retrospective study

The present study evaluated programmed cell death-ligand 1 (PD-L1) expression in tumor cells and in the tumor microenvironment (TME) and its association with clinical data in primary testicular diffuse large B cell lymphoma (DLBCL). PD-L1 was determined by immunohistochemistry in 30 patients with primary testicular DLBCL and assessed for associations with clinical characteristics, progression-free survival (PFS) and overall survival (OS). The mean patient age was 62.2 years. Overall, 10 (33.3%) patients had advanced-stage (stage III/IV) disease and 14 (46.7%) patients had an International Prognostic Index (IPI) of ≥3. The median follow-up time following orchiectomy was 23.5 months. During this time, 10 (33.3%) patients experienced disease progression and 11 (36.7%) patients succumbed. PD-L1 expression in tumor cells and in the TME was detected in 20 (66.7%) and 13 (43.3%) patients, respectively. PD-L1 expression on tumor cells and in the TME was higher in those at an early stage compared with patients with an advanced stage of disease (P=0.045 and 0.017, respectively). In addition, PD-L1 expression in tumor cells was higher in patients with a low IPI compared with those with a high IPI (P=0.019). A Kaplan-Meier analysis identified no association of PD-L1 expression on tumor cells with PFS (P=0.763) or OS (P=0.531), or of PD-L1 expression in the TME with PFS (P=0.572) or OS (P=0.934). The present study demonstrated that PD-L1 expression in tumor cells and in the TME was higher in patients at an early stage of disease compared with those at an advanced stage, and that PD-L1 expression on tumor cells was higher in patients with a low IPI than in those with a high IPI. Furthermore, PD-L1 expression in tumor cells and in the TME was not associated with PFS or OS.

Two Cases of Primary Testicular Lymphoma Presenting with Direct Spread along the Spermatic Cord and Gonadal Vessels

Primary testicular lymphoma is a rare testicular neoplasm that mainly affects elderly patients, with Human Immunodeficiency Virus (HIV) being a known risk factor in the younger population. Approximately 20% of patients will have disseminated disease with extra-nodal involvement at clinical presentation. Rarely, direct spread along the spermatic cord and gonadal vessels can occur and has been described in the literature. We present two cases of this phenomenon where the primary testicular tumour has spread along the gonadal vein to its origin at the inferior vena cava.

A case of primary testicular lymphoma with continuous spread along the gonadal vein and spermatic cord

Primary testicular lymphoma (PTL) is a rare form of non-Hodgkin's lymphoma more prevalent in males aged over 60 years old. PTL has a tendency to disseminate to systemic extranodal sites, however there has been a rare continuous spread involving the gonadal vein and spermatic cord. This method of dissemination has been described in 3 previous cases, and this case report presents another such case where such spread was noted, in a patient with a previous history of seminoma. Knowledge of this method of spread may increase the index of suspicion of PTL on cross-sectional imaging.

Intravenous but not intrathecal central nervous system-directed chemotherapy improves survival in patients with testicular diffuse large B-cell lymphoma

BACKGROUND

Testicular lymphoma is a rare malignancy affecting mainly elderly men, the majority representing diffuse large B-cell lymphoma (DLBCL). Its relapse rate is higher than that of nodal DLBCL, often affecting the central nervous system (CNS) with dismal prognosis.

PATIENTS AND METHODS

We searched for patients with testicular DLBCL (T-DLBCL) involvement from the pathology databases of Southern Finland University Hospitals and the Danish Lymphoma Registry. Clinical information was collected, and outcomes between treatment modalities were evaluated. Progression-free survival (PFS), disease-specific survival (DSS) and overall survival (OS) were assessed using Kaplan-Meier and Cox proportional hazards methods.

RESULTS

We identified 235 patients; of whom, 192 were treated with curative anthracycline-based chemotherapy. Full survival data were available for 189 patients. In univariate analysis, intravenous CNS-directed chemotherapy, and irradiation or orchiectomy of the contralateral testis translated into favourable PFS, DSS and OS, particularly among the elderly patients (each p ≤ 0.023). Intrathecal chemotherapy had no impact outcome. In multivariate analyses, the advantage of intravenous CNS-directed chemotherapy (hazard ration [HR] for OS, 0.419; 95% confidence interval [CI], 0.256-0.686; p = 0.001) and prophylactic treatment of contralateral testis (HR for OS, 0.514; 95% CI, 0.338-0.782; p = 0.002) was maintained. Rituximab improved survival only among high-risk patients (International Prognostic Index≥3, p = 0.019). The cumulative risk of CNS progression was 8.4% and did not differ between treatment modalities.

CONCLUSION

The results support the use of CNS-directed chemotherapy and prophylactic treatment of the contralateral testis in patients with T-DLBCL involvement. Survival benefit appears resulting from better control of systemic disease rather than prevention of CNS progression.

Testicular cancer among US men aged 50 years and older

BACKGROUND

The incidence of testicular cancer in the United States (US) has substantially increased in recent decades. The majority of testicular cancers are germ cell tumors (TGCT), which are the most commonly occurring malignancies among men aged 15-44 years in the US. To date, few studies have focused on testicular cancer among men aged ≥ 50 years. Thus, we sought to examine detailed descriptive features, including incidence rates and age patterns, of tumors that arise in the testes among men aged ≥ 50 years.

METHODS

Data from forty-one US cancer registries were included for the years 1999-2014. Incidence rates per 100,000 person-years and their 95% confidence intervals (CI) were calculated by race/ethnicity, histology, and age at diagnosis. Estimates of annual percent change (APC) were also calculated.

RESULTS

Age-specific incidence rates of spermatocytic tumors, sex cord stromal tumors and lymphomas rose with age, while age-specific incidence rates of seminomas and nonseminomas declined. Between 1999 and 2014, the incidence of nonseminoma (APC = 3.26, 95% CI: 2.27-4.25) increased more than any other tumor type. The incidence of seminoma (APC: 1.15, 95% CI: 0.59-1.71) also increased, while rates of testicular lymphoma (APC: -0.66, 95% CI: -1.16 to -0.16), spermatocytic tumors (APC: 0.42, 95% CI: -1.42 to 2.29), and sex cord stromal tumors (APC: 0.60, 95% CI: -3.21 to 4.55) remained relatively unchanged.

CONCLUSION

Given the distinct time-trends and age-specific patterns of testicular cancer in men aged ≥50 years, additional investigation of risk factors for these tumors is warranted.

Primary testicular lymphoma: A SEER analysis of 1,169 cases

Primary testicular lymphoma (PTL) is a rare lymphoid malignancy. The present retrospective study aimed to investigate the demographic characteristics and survival of patients with PTL, as well as the associated prognostic factors, using a population-based database. All adults diagnosed with PTL in the Surveillance, Epidemiology, and End Results database were identified between 1973 and 2013. The Kaplan-Meier method was used to estimate cause-specific survival (CSS). Log-rank test or multivariate Cox regression model was used to assess the influence of demographic and clinical parameters on CSS. A total of 1,169 patients with PTL were identified from the database, and the median age was 70 years. The predominant histological subtype was diffuse large B-cell lymphoma, which affected 82.9% (970/1,169) of patients, and 68.6% (802/1,169) of patients had early stage disease (stages I–II). Patients >70 years, those diagnosed at the earlier time period, or those who had advanced-stage symptoms had the worst 5-year CSS rates; however, treatment with rituximab significantly improved the 5-year CSS. In conclusion, this retrospective study presented data from the largest cohort of patients with PTL and described the effects of rituximab on the CSS of patients with PTL.

Stage I non-Hodgkin lymphoma: no plateau in disease-specific survival ?

Stage I non-Hodgkin lymphoma (NHL) is rare; prognostic impact of different histologic subtypes and treatment modality is still unclear. We used the Surveillance, Epidemiology and End Results (SEER) database to evaluate survival outcomes among adult patients (age ≥ 18 years, N = 58,230) diagnosed with stage I NHL of various histologic subtypes between 1998 and 2014. Five-year disease-specific survival of patients with stage I diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), marginal zone lymphoma (MZL), small lymphocytic lymphoma (SLL), Burkitt lymphoma (BL), mantle cell lymphoma (MCL), and peripheral T cell lymphoma (PTCL) was 82%, 92%, 95%, 89%, 78%, 77%, and 77%, respectively. The median disease-specific survival was not reached in all histologic subtypes analyzed; however, there does not appear to be a plateau in disease-specific survival of patients with stage I NHL irrespective of subtypes. Although lymphoma was the most common cause of death (40.7%), death from other cancer (17.4%) and cardiovascular disease (13.6%) were also frequent. Chemotherapy appeared favorably associated with OS in patients with DLBCL, BL, and MCL while patients with FL, MZL, SLL, and PTCL who require chemotherapy for initial treatment showed shorter OS. Patients with stage I NHL have favorable disease-specific survival; however, no plateau was seen regardless of histologic subtypes thus suggesting that patients may need attention and follow-up even in aggressive lymphomas after 5 years of remission.

The survival and prognostic factors of primary testicular lymphoma: two-decade single-center experience

This study aims to investigate the effect of different local testicular treatments and validate common prognostic factors on primary testicular lymphoma (PTL) patients. We retrospectively reviewed the clinical records of 32 patients from 1993 to 2017 diagnosed with PTL and included 22 patients for analysis. The Kaplan-Meier method, Log-rank test, and multivariate Cox proportional hazard regression analysis were applied to evaluate progression-free survival (PFS), overall survival (OS), and determine prognosis predictors. The median follow-up time was 30 months. Median OS and PFS were 96 months and 49 months, respectively. In univariate analysis, advanced Ann Arbor stage (III/IV) (P < 0.001), B symptoms (P < 0.001), and extranodal involvement other than testis (P = 0.001) were significantly associated with shorter OS and PFS. In multivariate analysis, Ann Arbor stage was significantly associated with OS (OR = 11.58, P = 0.049), whereas B symptom was significantly associated with PFS (OR = 11.79, P= 0.049). In the 10 patients with the systemic usage of rituximab, bilateral intervention could improve median OS from 16 to 96 months (P = 0.032). The study provides preliminary evidence on bilateral intervention in testes in the rituximab era and validates common prognostic factors for Chinese PTL patients.

Functional Parameters of 18F-FDG PET/CT in Patients with Primary Testicular Diffuse Large B-Cell Lymphoma

Fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron-emission tomography/computed tomography (PET/CT), a hybrid imaging technique that simultaneously provides functional and anatomical information, has been reported to be useful in lymphoma. The present study was to evaluate the functional parameters of ¹⁸F-FDG PET/CT in patients with testicular diffuse large B-cell lymphoma (DLBCL). We retrospectively reviewed medical records of 5095 patients with lymphoma who treated at West China Hospital between March 2003 and January 2017, and selected patients with ¹⁸F-FDG PET/CT findings and subsequently biopsy confirmed the invasion of testis with DLBCL. Maximum standardized uptake values (SUV_max), peak standardized uptake values (SUV_peak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the patients were measured. We evaluated the characteristics of ¹⁸F-FDG PET/CT in this population. Six patients ranged in age from 37 to 73 years (median age, 58 years) were included in the analysis. The mean SUV_max was 11.09 and varied between 7.20 and 19.75; mean SUV_peak was 9.56 and ranged between 6.79 and 14.39. In addition, mean MTV 42% was 18.4 and varied between 1.3 and 61.6; mean MTV 2.5 was 34.7 and varied significantly between 1.6 and 141.9. With regard to TLG, mean TLG 42% was 168.906 and ranged from 7.514 to 687.004, while mean TLG 2.5 was 253.972 and ranged from 8.400 to 1127.802. In conclusion, ¹⁸F-FDG PET/CT scan is a useful tool in patients with testicular DLBCL. SUV, MTV, and TLG may vary a lot in different patients. SUV_max of testicular DLBCL lesion is relatively higher than that of normal testis. Also, we provided a set of MTV and TLG data and firstly showed their significant correlation with overall survival, which indicated a potential prognostic value of MTV and TLG. However, studies with larger population are needed to confirm these findings.

T-cell inflamed tumor microenvironment predicts favorable prognosis in primary testicular lymphoma

Primary testicular lymphoma is a rare lymphoid malignancy, most often, histologically, representing diffuse large B-cell lymphoma. The tumor microenvironment and limited immune surveillance have a major impact on diffuse large B-cell lymphoma pathogenesis and survival, but the impact on primary testicular lymphoma is unknown. Here, the purpose of the study was to characterize the tumor microenvironment in primary testicular lymphoma, and associate the findings with outcome. We profiled the expression of 730 immune response genes in 60 primary testicular lymphomas utilizing the Nanostring platform, and used multiplex immunohistochemistry to characterize the immune cell phenotypes in the tumor tissue. We identified a gene signature enriched for T-lymphocyte markers differentially expressed between the patients. Low expression of the signature predicted poor outcome independently of the International Prognostic Index (progression-free survival: HR=2.810, 95%CI: 1.228-6.431, P=0.014; overall survival: HR=3.267, 95%CI: 1.406-7.590, P=0.006). The T-lymphocyte signature was associated with outcome also in an independent diffuse large B-cell lymphoma cohort (n=96). Multiplex immunohistochemistry revealed that poor survival of primary testicular lymphoma patients correlated with low percentage of CD3⁺CD4⁺ and CD3⁺CD8⁺ tumor-infiltrating lymphocytes (P<0.001). Importantly, patients with a high T-cell inflamed tumor microenvironment had a better response to rituximab-based immunochemotherapy, as compared to other patients. Furthermore, loss of membrane-associated human-leukocyte antigen complexes was frequent and correlated with low T-cell infiltration. Our results demonstrate that a T-cell inflamed tumor microenvironment associates with favorable survival in primary testicular lymphoma. This further highlights the importance of immune escape as a mechanism of treatment failure.

The cell-of-origin classification of diffuse large B cell lymphoma in a Korean population by the Lymph2Cx assay and its correlation with immunohistochemical algorithms

Cell-of-origin (COO) classification of diffuse large B cell lymphoma (DLBCL) is increasingly important due to its prognostic significance and the development of subtype-specific therapeutics. We compared the clinical utility of the Lymph2Cx assay against four widely used immunohistochemical algorithms in 150 R-CHOP-treated DLBCL patients using archival tissue. In contrast to the predominance of germinal center B cell-like (GCB) subtype in Western populations, Lymph2Cx assay classified more than half of the Korean cases as the activated B cell-like (ABC) subtype (ABC, 83/150 [55.3%]; GCB, 51/150 [34.0%]; unclassifiable, 16/150 [10.7%]). Predominance of ABC subtype tended to be more pronounced in the nodal lymphomas than in the extranodal lymphomas. However, among the primary extranodal sites, ABC subgroups predominated in primary testicular, breast, and adrenal gland lymphomas. The classification of COO by Lymph2Cx assay did not show any significant association with clinical parameters. The overall concordance rates of the immunohistochemical algorithms with the Lymph2Cx ranged from 78.0 to 84.3%. However, 47.1-66.7% of the cases of the Lymph2Cx-defined GCB subgroup were misclassified as the non-GCB class by the IHC algorithms. The survival of Lymph2Cx-classified COO subtypes was not significantly different in the present cohort. In conclusion, ABC subtype predominated over GCB in Korean patients. There are significant discrepancies between the immunohistochemistry and Lymph2Cx classifications, especially in GCB subtype.

PD-L1+ tumor-associated macrophages and PD-1+ tumor-infiltrating lymphocytes predict survival in primary testicular lymphoma

Primary testicular lymphoma is a rare and aggressive lymphoid malignancy, most often representing diffuse large B-cell lymphoma histologically. Tumor-associated macrophages and tumor-infiltrating lymphocytes have been associated with survival in diffuse large B-cell lymphoma, but their prognostic impact in primary testicular lymphoma is unknown. Here, we aimed to identify macrophages, their immunophenotypes and association with lymphocytes, and translate the findings into survival of patients with primary testicular lymphoma. We collected clinical data and tumor tissue from 74 primary testicular lymphoma patients, and used multiplex immunohistochemistry and digital image analysis to examine macrophage markers (CD68, CD163, and c-Maf), T-cell markers (CD3, CD4, and CD8), B-cell marker (CD20), and three checkpoint molecules (PD-L1, PD-L2, and PD-1). We demonstrate that a large proportion of macrophages (median 41%, range 0.08–99%) and lymphoma cells (median 34%, range 0.1–100%) express PD-L1. The quantity of PD-L1⁺ CD68⁺ macrophages correlates positively with the amount of PD-1⁺ lymphocytes, and a high proportion of either PD-L1⁺ CD68⁺ macrophages or PD-1⁺ CD4⁺ and PD-1⁺ CD8⁺ T cells translates into favorable survival. In contrast, the number of PD-L1⁺lymphoma cells or PD-L1⁻ macrophages do not associate with outcome. In multivariate analyses with IPI, PD-L1⁺ CD68⁺ macrophage and PD-1⁺ lymphocyte contents remain as independent prognostic factors for survival. In conclusion, high PD-L1⁺ CD68⁺ macrophage and PD-1⁺ lymphocyte contents predict favorable survival in patients with primary testicular lymphoma. The findings implicate that the tumor microenvironment and PD-1 – PD-L1 pathway have a significant role in regulating treatment outcome. They also bring new insights to the targeted thera py of primary testicular lymphoma.

Utility of FDG PET/CT in the Management of Primary Testicular Lymphoma

OBJECTIVE

Primary testicular lymphoma (PTL) is a form of extra-nodal lymphoma originating from the testicles. Currently, positron emission tomography (PET) with glucose analogue ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) is the most popular and widely used modality for evaluating tumor metabolism, and PTL usually displays increased ¹⁸F-FDG uptake. Despite the rapid increase in clinical applications of FDG PET/ computed tomography (CT), its role in PTL has neither been clearly defined nor reviewed systematically. This study reviews the usefulness and limitation of FDG PET/CT in the diagnosis and treatment of PTL.

METHODS

This study included 12 patients with PTL between 2004 and 2015. We retrospectively examined PET/CT results along with patient outcome. The maximum standardized uptake value (SUV_max) was calculated.

RESULTS

The mean overall survival (OS) and disease-free survival (DFS) was 44.5 months and 35.5 months, respectively. The mean SUV_max was identified as 18.5 in recurrent/metastatic group. The 1-year and 3-year OS was 94% and 69%, while the 1-year and 2-year DFS was 93.5% and 56%, respectively.

CONCLUSION

FDG PET/CT is very helpful in both staging and evaluating treatment response. Although it is not a perfect tool in the initial diagnosis, it might aid in the differential diagnosis of challenging testicular tumors. Pre-treatment and post-treatment FDG uptake values may also have a prognostic value in patients with PTL.

MYD88 L265P Mutation in Lymphoid Malignancies

Next-generation sequencing has revealed cancer genomic landscapes, in which over 100 driver genes that, when altered by intragenic mutations, can promote oncogenesis. MYD88 is a driver gene found in hematologic B-cell malignancies. A missense mutation (L265P) changing leucine at position 265 to proline in MYD88 is found in ∼90% of Waldenström macroglobulinemia (WM) cases and in significant portions of activated B-cell diffuse large B-cell lymphomas and IgM monoclonal gammopathy of undetermined significance. Few cancers such as WM have a single amino acid substitution in one gene like MYD88 L265P that occurs in ∼90% of cases, making WM paradigmatic for study of a single causative mutation in oncogenesis. In this review, we summarize the frequency and cancer spectrum of MYD88 L265P and its downstream effects in lymphoid cancers. Malignant B cells with MYD88 L265P are likely transformed from IgM-producing B cells either in response to T-cell-independent antigens or in response to protein antigens before class switching. We also discuss therapeutic strategies that include targeting Bruton tyrosine kinase and other kinases, interfering with the assembly of MYD88 and its interacting partners, and MYD88 L265P-specific peptide-based immunotherapy. Cancer Res; 78(10); 2457-62. ©2018 AACR.