Dematiaceous fungal infections: clinical and pathologic conundrums

Dematiaceous fungi are defined by pigment within their cell walls. They are increasingly recognised human pathogens, causing a wide range of clinical presentations, from localised subcutaneous infections to disseminated disease in rare cases. We report our institutional experience with diagnosis of dematiaceous fungal infections from 2005 to 2022 and highlight four instructive cases that clinically and pathologically mimicked other diseases for which the diagnosis was confirmed by fungal culture (one case) or supported by PCR with 28S rRNA and internal transcribed spacer primers (three cases). Two patients were immunocompromised and two had presumed exposure to the organism. In each highlighted case, fungal infection was not clinically suspected, and the pathologist was critical in making the diagnosis and ensuring appropriate clinical management, which was supplemented by fungal stains and novel molecular methods.

Uses and limitations of small-volume biopsies for the diagnosis of lymphoma

Although surgical biopsy remains the gold standard for the diagnosis of lymphoma, small-volume biopsies including fine-needle aspiration and core needle biopsy are increasingly being used as a first line diagnostic tool. Small-volume biopsies are safe, rapid and cost effective; however, diagnostic utility varies by lymphoma subtype. It is important for pathologists and clinicians to recognize both the strengths and limitations of such biopsies.

One procedure-one report: the Re-Imagine Cytopathology Task Force position paper on small tissue biopsy triage in anatomic pathology

INTRODUCTION

Endoscopic biopsy procedures increasingly generate multiple tissue samples from multiple sites, and frequently retrieve concurrent cytologic specimens and small core needle biopsies. There is currently lack of consensus in subspecialized practices as to whether cytopathologists or surgical pathologists should review such samples, and whether the pathology findings should be reported together or separately.

MATERIALS AND METHODS

In December 2021, the American Society of Cytopathology convened the Re-Imagine Cytopathology Task Force to examine various workflows that would facilitate unified pathology reporting of concurrently obtained biopsies and improve clinical care.

RESULTS AND CONCLUSIONS

This position paper summarizes the key points and highlights the advantages, challenges, and resources available to support the implementation of such workflows that result in "one procedure-one report".

Hodgkin Lymphoma and Its Differential Diagnosis: New Twists on an Old Challenge

Hodgkin lymphoma is a B-cell neoplasm that typically presents with localized, nodal disease. Tissues are characterized by few large neoplastic cells, usually comprising less than 10% of tissue cellularity, present in a background of abundant nonneoplastic inflammatory cells. This inflammatory microenvironment, although key to the pathogenesis, can make diagnosis a challenge because reactive conditions, lymphoproliferative diseases, and other lymphoid neoplasms may mimic Hodgkin lymphoma and vice versa. This review provides an overview of the classification of Hodgkin lymphoma, its differential diagnosis, including emerging and recently recognized entities, and strategies to resolve challenging dilemmas and avoid diagnostic pitfalls.

Neurolymphomatosis in Recrudescent Diffuse Large B-cell Lymphoma

Neurolymphomatosis is an uncommon manifestation of lymphoma, often presenting with painful polyneuropathy or polyradiculopathy and concomitant distal extremity weakness. Differentiation from other etiologies resulting in similar neuropathic symptoms such as compressive or inflammatory pathologies can be difficult and often results in delayed diagnosis. Here we describe a case of neurolymphomatosis affecting a 64-year-old man with a history of diffuse large B-cell lymphoma (DLBCL) in remission presenting with a right-sided foot drop following a gunshot wound. MRI at that time demonstrated thickening and enhancement of the cauda equina nerve roots. Over the course of the subsequent eight months, he developed left lower extremity sensory symptoms, left-sided foot drop and signs of upper motor neuron involvement, including left facial weakness, dysphonia, and dysphagia. ¹⁸F-FDG PET/CT revealed intensely avid left lumbosacral nerve roots, bilateral lower extremity and left upper extremity neurovascular bundles. Left sural nerve biopsies showed infiltration of DLBCL and confirmed neurolymphomatosis. We highlight the role of ¹⁸F-FDG PET/CT, with histological verification, for the diagnosis of an extended course of neurolymphomatosis occurring in the absence of typical painful neuropathy but with cranial and peripheral neuropathies.

Geographic Variability of Nodular Lymphocyte-Predominant Hodgkin Lymphoma

OBJECTIVES

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) differs from classic Hodgkin lymphoma (CHL) in terms of clinicopathologic features, including Epstein-Barr virus (EBV) association. CHL geographic variability is well known, with higher frequencies of mixed-cellularity subtype and EBV positivity in low/middle-income countries (LMICs), but there are few well-characterized series of NLPHL from LMICs.

METHODS

We detail clinicopathologic findings of 21 NLPHL cases received in consultation from Kenya and summarize reports of NLPHL with EBV testing published since 2000.

RESULTS

Median age of consultation cases was 36 years, and male/female ratio was 3.2. All cases involved peripheral lymph nodes and showed at least some B-cell-rich nodular immunoarchitecture, with prominent extranodular lymphocyte-predominant (LP) cells and T-cell-rich variant patterns most commonly seen. LP cells expressed pan-B-cell markers, including strong OCT2; lacked CD30 and CD15 expression in most cases; and were in a background of expanded/disrupted follicular dendritic cell meshworks and increased T-follicular helper cells. LP cells were EBV negative in 18 cases. Historical cases showed a low rate of EBV positivity with no significant difference between LMICs and high-income countries.

CONCLUSIONS

Unlike CHL, NLPHL shows few geographic differences in terms of clinicopathologic features and EBV association. These findings have implications for diagnosis, prognostication, and treatment of patients with NLPHL in LMICs.

Plasma cell myeloma: role of histopathology, immunophenotyping, and genetic testing

Myeloma is a malignant neoplasm of plasma cells with complex pathogenesis. Diagnosis and risk stratification require the integration of histology, radiology, serology, and genetic data. Bone marrow biopsies are essential for myeloma diagnosis by providing material for histologic and cytologic assessment as well as immunophenotypic and genetic studies. Flow cytometry and genetic studies are, in particular, becoming increasingly important for diagnosis, risk stratification, and assessment of treatment response. Myeloma has traditionally been characterized by recurrent cytogenetic abnormalities that can be divided into two subtypes: hyperdiploid, characterized by trisomies, and non-hyperdiploid, characterized by translocations involving chromosome 14. These abnormalities are thought to be primary events, initiating a premalignant state, which progresses to myeloma through the acquisition of secondary mutations. The emergence of next-generation sequencing has led to the discovery of numerous mutations and gene fusions that comprise the heterogenous genomic landscape of myeloma. As the underlying pathogenesis of myeloma continues to be delineated, possible therapeutic targets have also emerged. Herein, we describe the importance of histology, immunophenotype, and mutational analysis in the assessment of myeloma.

Accuracy of Pathologic Diagnosis in Patients With Lymphoma and Survival: A Prospective Analysis From Botswana

PURPOSE

With intense HIV epidemics, southern African countries have a high burden of classic Hodgkin lymphoma (CHL) and non-Hodgkin lymphoma (NHL). However, suboptimal access to pathology resources limits subtype classification. We sought to assess the diagnostic accuracy of specimens classified as lymphoma and to determine association between discordant pathologic diagnosis and overall survival.

METHODS

Seventy patients with CHL or NHL and treated at three Botswana hospitals from 2010 to 2016 were analyzed. Local pathologic assessment relied primarily on morphology. All cases underwent secondary US hematopathology review, which is considered gold standard.

RESULTS

The median follow-up was 58 months. The overall reclassification rate was 20 of 70 cases (29%). All 20 CHL cases were correctly classified in Botswana, and mixed cellularity was the most common subtype, diagnosed in 11 (55%) cases. Of 47 confirmed NHL cases, diffuse large B-cell lymphoma was the final US diagnosis in 28 cases (60%), another aggressive B-cell NHL in nine (19%), an indolent B-cell NHL in six (13%), and T-cell NHL in four (9%). Common types of diagnostic discordance included NHL subtype reclassification (11 of 20, 55%) and CHL reclassified as NHL (7 of 20, 35%). Concordant versus discordant diagnosis after secondary review was associated with improved 5-year overall survival (60.1% v 26.3%, P = .0066). Discordant diagnosis was independently associated with increased risk of death (adjusted hazard ratio 2.733; 95% CI, 1.102 to 6.775; P = .0300) even after stratifying results by CHL versus NHL.

CONCLUSION

In this single prospective cohort, discordant pathologic diagnosis was associated with a nearly three-fold increased risk of death. Limited access to relatively basic diagnostic techniques impairs treatment decisions and leads to poor patient outcomes in low-resource countries.

Epstein-Barr-virus-positive large B-cell lymphoma associated with breast implants: an analysis of eight patients suggesting a possible pathogenetic relationship

Breast implant anaplastic large cell lymphoma (ALCL) is a T-cell neoplasm arising around textured breast implants that was recognized recently as a distinct entity by the World Health Organization. Rarely, other types of lymphoma have been reported in patients with breast implants, raising the possibility of a pathogenetic relationship between breast implants and other types of lymphoma. We report eight cases of Epstein-Barr virus (EBV)-positive large B-cell lymphoma associated with breast implants. One of these cases was invasive, and the other seven neoplasms were noninvasive and showed morphologic overlap with breast implant ALCL. All eight cases expressed B-cell markers, had a non-germinal center B-cell immunophenotype, and were EBV+ with a latency type III pattern of infection. We compared the noninvasive EBV+ large B-cell lymphoma cases with a cohort of breast implant ALCL cases matched for clinical and pathologic stage. The EBV+ large B-cell lymphoma cases more frequently showed a thicker capsule, and more often were associated with calcification and prominent lymphoid aggregates outside of the capsule. The EBV+ B-cell lymphoma cells were more often arranged within necrotic fibrinoid material in a layered pattern. We believe that this case series highlights many morphologic similarities between EBV+ large B-cell lymphoma and breast implant ALCL. The data presented suggest a pathogenetic role for breast implants (as well as EBV) in the pathogenesis of EBV+ large B-cell lymphoma. We also provide some histologic findings useful for distinguishing EBV+ large B-cell lymphoma from breast implant ALCL in this clinical setting.

Pediatric Hodgkin Lymphoma, Version 3.2021

Hodgkin lymphoma (HL) is a highly curable form of cancer, and current treatment regimens are focused on improving treatment efficacy while decreasing the risk of late effects of treatment. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for pediatric HL provide recommendations on the workup, diagnostic evaluation, and treatment of classic HL, including principles of pathology, imaging, staging, systemic therapy, and radiation therapy. This portion of the NCCN Guidelines focuses on the management of pediatric classic HL in the upfront and relapsed/refractory settings.

Clinicopathologic Features of Peripheral T-Cell Lymphoma in Sub-Saharan Africa

OBJECTIVES

Peripheral T-cell lymphomas (PTCLs) are heterogeneous, clinically aggressive, and rare. Subtype distribution varies by geographic location; however, data from sub-Saharan Africa (SSA) are lacking. We sought to elucidate clinicopathologic features of PTCL in SSA.

METHODS

We reviewed PTCL consultation cases from three SSA countries. PTCL subtype was determined per 2017 World Health Organization classification. Cases with sufficient material were evaluated by polymerase chain reaction for human T-cell leukemia virus type 1 (HTLV-1) and T-cell receptor γ (TCRG) rearrangement.

RESULTS

Among 32 cases, median age was 45 years and male-to-female ratio was 1.7. Thirty (94%) of 32 cases required additional workup for subclassification. PTCL, not otherwise specified (PTCL-NOS) was the most common subtype (13/32, 41%), followed by PTCL with T-follicular helper phenotype (6/32, 19%) and systemic anaplastic large cell lymphoma (6/32, 19%). Four (16%) of 25 cases were Epstein-Barr virus positive (EBV+) (2/2 extranodal natural killer/T-cell lymphoma, 1/13 PTCL-NOS, and 1/4 angioimmunoblastic T-cell lymphoma with EBV+ immunoblasts). Two (15%) of 13 patients with PTCL-NOS were human immunodeficiency virus positive. No cases with evaluable DNA (0/15) were HTLV-1 positive, and 9 of 10 showed clonal TCRG rearrangements.

CONCLUSIONS

In comparison to Western studies, PTCLs from SSA show similar subtype distribution and male predominance but a younger age at diagnosis. Appropriate diagnosis of PTCL requires extensive ancillary testing not readily available in low-income countries, including much of SSA.

Simultaneous Identification of Cell of Origin, Translocations, and Hotspot Mutations in Diffuse Large B-Cell Lymphoma Using a Single RNA-Sequencing Assay

OBJECTIVES

Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin lymphoma with a heterogenous genetic landscape that can require multiple assays to characterize. We reviewed a 1-step RNA-based assay to determine cell of origin (COO), detect translocations, and identify mutations and to assess the role of the assay in diagnosis.

METHODS

Using a single custom Archer FusionPlex Lymphoma panel, we performed anchored multiplex polymerase chain reaction-based RNA sequencing on 41 cases of de novo DLBCL. Each case was subclassified by COO, and gene fusions and hotspot mutations were identified. The findings were then compared with COO classification by the Hans immunohistochemical algorithm and NanoString technology, cytogenetics, and fluorescence in situ hybridization results.

RESULTS

Concordant COO classification by the FusionPlex panel and NanoString was observed in 35 of 41 cases (85.3%), with NanoString and Hans concordant in 33 of 41 cases (80.5%) and FusionPlex and Hans concordant in 33 of 41 cases (80.5%). The FusionPlex assay also detected 6 of 11 BCL6 translocations (4 cryptic), 2 of 3 BCL2 translocations, and 2 of 4 MYC translocations. Mutations were detected in lymphoma-related genes in 24 of 41 cases.

CONCLUSION

This FusionPlex assay offers a single method for COO classification, mutation detection, and identification of important translocations in DLBCL. Although not replacing traditional testing, it could offer useful data when limited tissue is available.

Subtype-specific and co-occurring genetic alterations in B-cell non-Hodgkin lymphoma

B-cell non-Hodgkin's lymphoma (B-NHL) encompasses multiple clinically and phenotypically distinct subtypes of malignancy with unique molecular etiologies. Common subtypes of B-NHL such as diffuse large B-cell lymphoma (DLBCL) have been comprehensively interrogated at the genomic level. But rarer subtypes such as mantle cell lymphoma (MCL) remain sparsely characterized. Furthermore, multiple B-NHL subtypes have thus far not been comprehensively compared using the same methodology to identify conserved or subtype-specific patterns of genomic alterations. Here, we employed a large targeted hybrid-capture sequencing approach encompassing 380 genes to interrogate the genomic landscapes of 685 B-NHL tumors at high depth; including DLBCL, MCL, follicular lymphoma (FL), and Burkitt lymphoma (BL). We identified conserved hallmarks of B-NHL that were deregulated in the majority of tumor from each subtype, including the frequent genetic deregulation of the ubiquitin proteasome system (UPS). In addition, we identified subtype-specific patterns of genetic alterations, including clusters of co-occurring mutations and DNA copy number alterations. The cumulative burden of mutations within a single cluster were more discriminatory of B-NHL subtypes than individual mutations, implicating likely patterns of genetic cooperation that contribute to disease etiology. We therefore provide the first cross-sectional analysis of mutations and DNA copy number alterations across major B-NHL subtypes and a framework of co-occurring genetic alterations that deregulate genetic hallmarks and likely cooperate in lymphomagenesis.

Improving Malignancy Detection Rates in Body Fluids Submitted to the Hematology Laboratory for Nucleated Cell Count and Differential: A Quality Improvement Study

CONTEXT.—

Body fluid specimens are regularly submitted to the hematology laboratory for cell count and differential. Unless there is high clinical suspicion for malignancy, most cases lack concurrent cytology review and may not benefit from more focused examination for malignancy.

OBJECTIVE.—

To compare rates of malignancy detection before and after fluid-focused training for hematology technologists as part of a quality improvement initiative.

DESIGN.—

During an 8-week pretraining period, body fluids submitted to the cytology laboratory were correlated with concurrent hematology specimens. After slide review and training sessions for the hematology technologists, the same data were collected for a 4-week period. Discrepant cases were reviewed by hematology laboratory supervisors and pathologists.

RESULTS.—

We collected 465 pretraining and 249 posttraining body fluids with concurrent cytology and hematology evaluation. In the pretraining cohort, 48 cases (10.3%) were diagnosed as malignant by cytology; of those, 33 were detected by hematology. In the posttraining cohort, 30 cases (12.0%) were diagnosed as malignant by cytology of which 27 were detected by hematology. Of the 18 discrepant cases (all carcinomas), hematology slide review showed definite features of malignancy in 15 and no tumor cells in 3. The malignancy detection rate by the hematology laboratory significantly improved after training (68.8% versus 90.0%, P = .01).

CONCLUSIONS.—

We demonstrate the comparatively lower malignancy detection rate for body fluid specimens processed in our hematology laboratory, particularly for carcinomas. Hematology technologist education/training improved the malignancy detection rate, an important quality improvement given the large proportion of body fluids undergoing hematology evaluation without concurrent cytology reviews.

Biomarkers for Risk Stratification in Patients With Previously Untreated Follicular Lymphoma Receiving Anti-CD20-based Biological Therapy

Follicular lymphoma (FL) is an indolent B-cell neoplasm of germinal center origin. Standard treatment regimens consist of anti-CD20 therapy with or without chemotherapy. While high response rates to initial therapy are common, patients ultimately relapse or have progressive disease. Clinical risk factors such as the Follicular Lymphoma International Prognostic Index (FLIPI) have been identified, but there is a need for prognostic and predictive biomarkers. We studied markers of lymphoma cells and tumor microenvironment by immunohistochemistry in tissue samples from patients enrolled in 1 of 4 phase 2 trials of anti-CD20-based biological therapy for previously untreated grades 1 to 2 or 3A FL. Results were correlated with progression-free survival (PFS) and PFS status at 24 months. The 4 trials included 238 patients (51.1% male, median age: 55 y) with stage III, IV, or bulky stage II disease. By FLIPI, 24.6% had low-risk, 56.8% had intermediate-risk, and 18.6% had high-risk disease. The outcome differed significantly for patients treated with lenalidomide and rituximab (CALGB 50803) compared with the other 3 trials (median: PFS not reached vs. 3.0 y, hazard ratio=3.47, 95% confidence interval: 2.11-5.72); therefore, data were stratified by clinical trial (CALGB 50803 vs. all others) and adjusted for FLIPI risk group. Among 154 patients with available tissue, interfollicular BCL6 positivity, interfollicular CD10 positivity, and elevated Ki67 proliferation index ≥30% within neoplastic follicles were each associated with inferior PFS and a high risk of the early event by PFS status at 24 months. We identify promising biomarkers for FL risk stratification that warrant further validation in phase 3 trials.

CD30-positive lymphomatous (nonleukemic) variant of adult T-cell leukemia/lymphoma, HTLV-1 associated

Nonleukemic variant of HTLV-1-associated adult T-cell leukemia lymphoma (ATLL) is a rare variant, and herein, we describe a case with strong and diffuse positivity of neoplastic cells for CD30. Even though ATLL is aggressive entity with poor prognosis, in our case, there was very good clinical response achieved with brentuximab-containing regimen. Therefore, HTLV-1-associated ATLL can be included in the differential diagnostic approach of CD30-positive lymphoproliferative disorders.

Diffuse Large B-Cell Lymphoma in Kenya: MYC, BCL2, and the Cell of Origin

PURPOSE

Diffuse large B-cell lymphoma (DLBCL) is the most commonly diagnosed non-Hodgkin lymphoma in adults in Kenya. Cell of origin (COO) and double expression of MYC and BCL2 are two important prognostic factors for DLBCL. A small subset (5% to 10%) of DLBCL cases show positivity for CD5 and are associated with poor prognosis, whereas CD30 antigen, seen in up to 10% of cases, may be a useful target for therapy. We sought to determine the prevalence of MYC/BCL2 double expression, COO, and proportion of Epstein-Barr virus positivity among patients with DLBCL diagnosed at a tertiary referral laboratory in Kenya.

PATIENTS AND METHODS

All cases of DLBCL diagnosed from 2012 through 2015 in our pathology department were analyzed. Tumor tissue microarray sections were stained with CD20, CD3, CD5, CD30, BCL2, BCL6, CD10, MUM1, MYC, and Ki67, classified for COO on the basis of the Hans algorithm, and subjected to Epstein-Barr virus-encoded small RNAs in situ hybridization.

RESULTS

Among 165 DLBCL cases, the median age was 50 years, and there was no sex predilection. Only 18 (10.9%) cases showed double expression for MYC and BCL2. Germinal center B (GCB)-cell type DLBCL accounted for 67 cases (40.6%) and 97 cases (59.4%) were classified as non-GCB. The mean Ki67 proliferation index was significantly higher in the double-expressing (45%) and non-GCB groups (36%) compared with the non–double-expressing group (29%) and GCB group (26%). Sixteen cases (9.7%) were Epstein-Barr virus-encoded small RNAs positive, 12 (75%) of which were non-GCB.

CONCLUSION

DLBCL in Kenya is seen in much younger patients with the poor prognostic non–GCB-type accounting for 59.4% of cases. MYC and BCL2 double expression was seen in fewer tumors than reported in the literature and in significantly older patients.

Lymphomas of the Mediastinum and Their Differential Diagnosis

Lymphoma is the most common malignancy involving the mediastinum but can be challenging to diagnose on small biopsy specimens. This review provides a pattern-based approach to help triage small tissue samples for the diagnosis of mediastinal lymphoid proliferations, with focus on the main primary mediastinal lymphomas. The use of ancillary studies is highlighted, along with considerations to avoid misdiagnosis and scenarios to request additional tissue.

Best Practices Guideline for the Pathologic Diagnosis of Breast Implant-Associated Anaplastic Large-Cell Lymphoma

PURPOSE

To provide guidelines for the accurate pathologic diagnosis of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), the preoperative evaluation of the patient with suspected BIA-ALCL, and the pathologic evaluation of the capsulectomy specimen.

METHODS

To better inform patients and healthcare providers about BIA-ALCL, we convened to review diagnostic procedures used in the evaluation of patients with suspected BIA-ALCL. We focused on the processing of the seroma fluid/effusion surrounding the implant, the handling of capsulectomy specimens following removal of implant(s), and the preoperative evaluation of the patient with suspected BIA-ALCL. Recommendations were based on the published literature and our experience to optimize procedures to obtain an accurate diagnosis and assess for tumor invasion and the extent of the disease.

RECOMMENDATIONS

Early diagnosis of BIA-ALCL is important as the disease can progress and deaths have been reported. Because the most common presentation of BIA-ALCL is swelling of the breast with fluid collection, an accurate diagnosis requires cytologic evaluation of the effusion fluid surrounding the affected implant. The first priority is cytocentrifugation and filtration of fresh, unfixed effusion fluid to produce air-dried smears that are stained with Wright-Giemsa or other Romanowsky-type stains. Preparation of a cell block is desirable to allow for hematoxylin and eosin staining and immunohistochemical analysis of formalin-fixed, paraffin-embedded histologic sections. Cell block sections can be used for polymerase chain reaction-based investigation of T-cell receptor gene rearrangement to detect clonality. Fixation and mapping of the capsulectomy specimen to select multiple representative sections are advised to assess for microscopic tumor involvement and capsular invasion. It is appropriate to assess lymph node involvement by excisional biopsy material rather than fine needle aspiration, due to propensity for focal involvement.

Plasmablastic Lymphomas: Characterization of Tumor Microenvironment Using CD163 and PD-1 Immunohistochemistry

This study aims to characterize the tumor microenvironment of plasmablastic lymphoma (PBL) in regard to the quantities of CD163(+) tumor associated macrophages (TAM) and PD1(+) tumor infiltrating lymphocytes (TIL). This article also reviews the existing knowledge of the role of PD-1/PD-L1 pathway in the tumor microenvironment of hematopoietic neoplasms, discusses potential mechanisms to explain our findings, and outlines areas for future studies. We performed CD163 and PD1 immunohistochemical studies in 11 cases classified as plasmablastic lymphoma, and recorded the percentages of positive TAMs and TILs. Based on previous studies, cut off values of ≥30% and >5% were used to classify the cases into high TAMs and TILs, respectively. We determined that the majority of cases (8 of 11, or 73%) had high percentage of TAMs, while only a minority had high percentage of TILs (3 of 11, or 27%). Our data shows a trend towards a negative correlation between TAMs and TILs (p=0.08), and a predominance of the pattern TAM^high/TIL^low (7 of 11, or 63%) compared to other patterns. The microenvironment of plasma-blastic lymphoma tends to show high percentage of TAMs (≥30%) combined with low percentage of TILs (≤5%). Additional studies are needed to determine the clinical significance of TILs and the influence of EBV and HIV infections on numbers of TILs in PBL. As high microenvironment TAMs have been associated with high microenvironment PD-L1 in other hematopoietic malignancies, our data supports the need for future studies on the expression of PD-L1 in PBL.

A Case of Fever and Erythema Nodosum-Like Lesions Leading to a New Diagnosis of Gamma-Delta T-Cell Lymphoma Complicated by Hemophagocytic Lymphohistiocytosis

A 69-year-old Vietnamese female presented with fever and new-onset tender subcutaneous nodules on her trunk and lower extremities initially thought to be clinically consistent with erythema nodosum. A biopsy showed an atypical, predominantly lobular lymphocytic panniculitis with admixed neutrophils, karyorrhectic debris, and histiocytes with subcutaneous fat necrosis. Immunohistochemistry was consistent with gamma-delta T-cell lymphoma. The patient was initiated on a chemotherapy regimen of cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisone (CHOEP) with partial remission, and is currently undergoing evaluation for bone marrow transplant. This case highlights the ability of cutaneous gamma-delta T-cell lymphoma to mimic more common cutaneous conditions such as erythema nodosum, and stresses the importance of a broad differential for new presentation of tender subcutaneous nodules with concomitant systemic symptoms.

Machine Learning Models Improve the Diagnostic Yield of Peripheral Blood Flow Cytometry

OBJECTIVES

Peripheral blood flow cytometry (PBFC) is useful for evaluating circulating hematologic malignancies (HM) but has limited diagnostic value for screening. We used machine learning to evaluate whether clinical history and CBC/differential parameters could improve PBFC utilization.

METHODS

PBFC cases with concurrent/recent CBC/differential were split into training (n = 626) and test (n = 159) cohorts. We classified PBFC results with abnormal blast/lymphoid populations as positive and used two models to predict results.

RESULTS

Positive PBFC results were seen in 58% and 21% of training cases with and without prior HM (P < .001). % neutrophils, absolute lymphocyte count, and % blasts/other cells differed significantly between positive and negative PBFC groups (areas under the curve [AUC] > 0.7). Among test cases, a decision tree model achieved 98% sensitivity and 65% specificity (AUC = 0.906). A logistic regression model achieved 100% sensitivity and 54% specificity (AUC = 0.919).

CONCLUSIONS

We outline machine learning-based triaging strategies to decrease unnecessary utilization of PBFC by 35% to 40%.

Design and clinical validation of a point-of-care device for the diagnosis of lymphoma via contrast-enhanced microholography and machine learning

The identification of patients with aggressive cancer who require immediate therapy is a health challenge in low-income and middle-income countries. Limited pathology resources, high healthcare costs and large-case loads call for the development of advanced standalone diagnostics. Here, we report and validate an automated, low-cost point-of-care device for the molecular diagnosis of aggressive lymphomas. The device uses contrast-enhanced microholography and a deep-learning algorithm to directly analyse percutaneously obtained fine-needle aspirates. We show the feasibility and high accuracy of the device in cells, as well as the prospective validation of the results in 40 patients clinically referred for image-guided aspiration of nodal mass lesions suspicious for lymphoma. Automated analysis of human samples with the portable device should allow for the accurate classification of patients with benign and malignant adenopathy.

Impact of HIV Infection on the Clinical Presentation and Survival of Non-Hodgkin Lymphoma: A Prospective Observational Study From Botswana

PURPOSE

Botswana has a high prevalence of HIV infection. Currently, there are few data regarding the sociodemographic factors, clinical characteristics, and outcomes of non-Hodgkin lymphoma (NHL)-an AIDS-defining cancer-in the country.

PATIENTS AND METHODS

This study used a prospective cancer registry to identify patients with a new diagnosis of NHL reporting for specialty cancer care at three hospitals in Botswana between October 2010 and August 2016. Treatment patterns and clinical outcomes were analyzed.

RESULTS

One hundred four patients with a new diagnosis of NHL were enrolled in this study, 72% of whom had HIV infection. Compared with patients not infected with HIV, patients infected with HIV were younger (median age, 53.9 v 39.1 years; P = .001) and more likely to present with an aggressive subtype of NHL (65.5% v 84.0%; P = .008). All patients infected with HIV received combined antiretroviral therapy throughout the course of the study, and similar chemotherapeutic regimens were recommended for all patients, regardless of subtype or HIV status (six to eight cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone; or cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab). There was no difference in 1-year mortality among patients not infected with HIV and patients infected with HIV (unadjusted analysis, 52.9% v 37.1%; hazard ratio [HR], 0.73; P = .33; adjusted analysis, HR, 0.57; P = .14). However, when compared with a cohort of patients in the United States matched by subtype, stage, age, sex, and race, patients in Botswana fared worse (1-year mortality, 22.8% v 46.3%; HR, 1.89; P = .001).

CONCLUSION

Among patients with NHL reporting for specialty cancer care in Botswana, there is no association between HIV status and 1-year survival.

Outcomes after Allogeneic Stem Cell Transplantation in Patients with Double-Hit and Double-Expressor Lymphoma

Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are associated with resistance to frontline and salvage immunochemotherapy, as well as autologous stem cell transplantation (SCT). We hypothesized that allogeneic SCT (alloSCT) could overcome the chemoresistance associated with DEL/DHL. We retrospectively studied the impact of DEL/DHL status in a multicenter cohort of patients who underwent alloSCT for relapsed/refractory (rel/ref) aggressive B cell non-Hodgkin lymphoma (B-NHL). Seventy-eight patients transplanted at 3 centers in whom tumor tissue was available for immunohistochemistry and fluorescence in situ hybridization were enrolled; 47% had DEL and 13% had DHL. There were no significant differences in 4-year progression-free (PFS) or overall survival (OS) between patients with DEL compared with patients without DEL (PFS 30% versus 39%, P = .24; OS 31% versus 49%, P = .17) or between patients with DHL compared with patients without DHL (PFS 40% versus 34%, P = .62; OS 50% versus 38%, P = .46). The lack of association between DEL or DHL and outcome was confirmed in multivariable models, although inadequate sample size may have limited our ability to detect significant differences. In our cohort alloSCT produced durable remissions in patients with rel/ref aggressive B-NHL irrespective of DEL and DHL status, justifying its consideration in the treatment of patients with rel/ref DEL/DHL.

mTOR, VEGF, PDGFR, and c-kit signaling pathway activation in Kaposi sarcoma

Kaposi sarcoma (KS) is a locally progressive, intermediate-grade vascular neoplasm with no known cure, high recurrence rates, and potential for wide dissemination. Low efficacy and high toxicity limit current therapeutic options for advanced disease. Activation of mammalian target of rapamycin (mTOR), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and c-kit signaling pathways has been implicated in KS pathogenesis and may suggest a role for targeted inhibitors. KS cases were retrospectively retrieved (N=274), most (90%) associated with human immunodeficiency virus. Tissue microarray slides were stained with human herpes virus-8, Friend leukemia integration 1 transcription factor, CD117 (c-kit), phospho-S6 (pS6), PDGF receptor-β, VEGF, and phospho-mTOR. Both intensity and extent of staining were scored. Multiplying these scores for each core yielded total staining H-scores. Human herpes virus-8 was positive in 87% and Friend leukemia integration 1 transcription factor in 95.7% of cases. Most were also VEGF+ (97.6%), pS6+ (95.7%), CD117+ (92.5%), and PDGFRB+ (87.4%). Approximately half (55.6%) were phospho-mTOR+. There was no significant difference in staining among patients with low (<500 cells/mm³) or preserved CD4 T-cell counts. Immunohistochemistry confirms upregulation of the mTOR, PDGF, VEGF, and c-kit pathways in a large cohort of KS samples. Of proteins tested, pS6, downstream of mTOR, demonstrated the highest proportion of strong positivity (67.1%). These results support the possibility of using targeted inhibitors in KS. Overexpression was independent of CD4 count, suggesting that even patients with low counts may be targeted therapy candidates.

Diagnostic work-up of acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by a clonal expansion of undifferentiated myeloid precursors resulting in impaired hematopoiesis and bone marrow failure. In 2016, the World Health Organization (WHO) published revisions to the classification of myeloid neoplasms and acute leukemias. Similar to the 2008 classification, the updated classification incorporates clinical features, morphology, immunophenotyping, and cytogenetics, with greater emphasis on molecular genetics, to define disease entities. This brief review addresses the various components of pathologic assessment to establish a diagnosis of AML and to help risk stratify patients, with an emphasis on newer techniques used in the detection of mutations with prognostic significance, as well as assays employed in the evaluation of minimal residual disease following treatment.

Diffuse large B-cell lymphoma with concurrent high MYC and BCL2 expression shows evidence of active B-cell receptor signaling by quantitative immunofluorescence

B-cell receptor (BCR)-mediated signaling plays an important role in the pathogenesis of a subset of diffuse large B-cell lymphoma (DLBCL), and novel agents targeting this pathway are now in clinical use. We have previously identified a signature of active BCR signaling on formalin-fixed paraffin-embedded specimens using quantitative immunofluorescence, allowing for identification of patients who might benefit from anti-BCR therapies. We sought to characterize the clinicopathologic significance of active BCR signaling in DLBCL by correlating measures of signaling intensity with clinical features and various tumor cell characteristics. High MYC and concurrent high MYC and BCL2 double-expression was positively correlated with individual markers of active BCR signaling and cases with MYC/BCL2 double-expression showed overall greater BCR activation compared to cases lacking double-expression. Our findings suggest that the BCR signaling pathway may be more active in MYC/BCL2 double-expressor DLBCL and may represent a rational therapeutic target in this aggressive DLBCL subgroup.

Relapsed or Refractory Double-Expressor and Double-Hit Lymphomas Have Inferior Progression-Free Survival After Autologous Stem-Cell Transplantation

Purpose Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are subtypes of diffuse large B-cell lymphoma (DLBCL) associated with poor outcomes after standard chemoimmunotherapy. Data are limited regarding outcomes of patients with relapsed or refractory (rel/ref) DEL or DHL who undergo autologous stem-cell transplantation (ASCT). We retrospectively studied the prognostic impact of DEL and DHL status on ASCT outcomes in patients with rel/ref DLBCL. Methods Patients with chemotherapy-sensitive rel/ref DLBCL who underwent ASCT at two institutions and in whom archival tumor material was available were enrolled. Immunohistochemistry for MYC, BCL2, and BCL6 and fluorescence in situ hybridization (FISH) for MYC were performed. In cases with MYC rearrangement or copy gain, FISH for BCL2 and BCL6 was also performed. Results A total of 117 patients were included; 44% had DEL and 10% had DHL. DEL and DHL were associated with inferior progression-free survival (PFS), and DHL was associated with poorer overall survival (OS). The 4-year PFS in patients with DEL compared with those with non-DEL was 48% versus 59% ( P = .049), and the 4-year OS was 56% versus 67% ( P = .10); 4-year PFS in patients with DHL compared with those with non-DHL was 28% versus 57% ( P = .013), and 4-year OS was 25% versus 61% ( P = .002). The few patients with concurrent DEL and DHL had a poor outcome (4-year PFS, 0%). In multivariable models, DEL and DHL were independently associated with inferior PFS, whereas DHL and partial response ( v complete response) at transplant were associated with inferior OS. Conclusion DEL and DHL are both associated with inferior outcomes after ASCT in patients with rel/ref DLBCL. Although ASCT remains a potentially curative approach, these patients, particularly those with DHL, are a high-risk subset who should be targeted for investigational strategies other than standard ASCT.

Next-generation sequencing-based detection of circulating tumour DNA After allogeneic stem cell transplantation for lymphoma

Next-generation sequencing (NGS)-based circulating tumour DNA (ctDNA) detection is a promising monitoring tool for lymphoid malignancies. We evaluated whether the presence of ctDNA was associated with outcome after allogeneic haematopoietic stem cell transplantation (HSCT) in lymphoma patients. We studied 88 patients drawn from a phase 3 clinical trial of reduced-intensity conditioning HSCT in lymphoma. Conventional restaging and collection of peripheral blood samples occurred at pre-specified time points before and after HSCT and were assayed for ctDNA by sequencing of the immunoglobulin or T-cell receptor genes. Tumour clonotypes were identified in 87% of patients with adequate tumour samples. Sixteen of 19 (84%) patients with disease progression after HSCT had detectable ctDNA prior to progression at a median of 3·7 months prior to relapse/progression. Patients with detectable ctDNA 3 months after HSCT had inferior progression-free survival (PFS) (2-year PFS 58% vs. 84% in ctDNA-negative patients, P = 0·033). In multivariate models, detectable ctDNA was associated with increased risk of progression/death (Hazard ratio 3·9, P = 0·003) and increased risk of relapse/progression (Hazard ratio 10·8, P = 0·0006). Detectable ctDNA is associated with an increased risk of relapse/progression, but further validation studies are necessary to confirm these findings and determine the clinical utility of NGS-based minimal residual disease monitoring in lymphoma patients after HSCT.

The immunophenotypic spectrum of primary mediastinal large B-cell lymphoma reveals prognostic biomarkers associated with outcome

Primary mediastinal large B-cell lymphoma (PMBL) is a distinct subtype of diffuse large B-cell lymphoma (DLBCL) that shows overlap with classical Hodgkin lymphoma (CHL) and a favorable prognosis compared to mediastinal gray-zone lymphoma (MGZL). We performed immunohistochemistry on initial diagnostic specimens of 49 cases of uniformly treated PMBL to determine the frequency and clinical significance of expression of antigens commonly seen in CHL and MGZL, along with markers previously shown to be prognostic in DLBCL, not otherwise specified. The median age was 37 years with a female:male ratio of 2.3. After a median follow-up of 78 months, 24% of patients had relapsed or refractory disease and 22% had died; the 5-year PFS was 70%. Variable CD15 expression was seen in 31% of cases, but was not associated with adverse outcome. Hans cell-of-origin, proliferation index, and MYC/BCL2 coexpression were not associated with outcome, while low PDL1 (P = 0.011) and high MUM1 (P = 0.065) staining were each associated with shorter PFS. A biologic risk score (one point each for low PDL1 and high MUM1) stratified patients into three prognostic risk groups for PFS (P = 0.001) and OS (P = 0.032). On separate multivariate models, low PDL1 was independent of R-IPI risk group for PFS (HR 6.0, P = 0.023), as was a biologic risk score of 2 (HR 5.6, P = 0.011). Incorporation of the biologic risk score sub-stratified patients within R-IPI groups for both PFS (P < 0.001) and OS (P < 0.001). In summary, we characterize the immunophenotypic spectrum of PMBL and identify PDL1 and MUM1 as prognostic biomarkers for high-risk disease. Am. J. Hematol. 91:E436-E441, 2016. © 2016 Wiley Periodicals, Inc.

Holographic Assessment of Lymphoma Tissue (HALT) for Global Oncology Field Applications

Low-cost, rapid and accurate detection technologies are key requisites to cope with the growing global cancer challenges. The need is particularly pronounced in resource-limited settings where treatment opportunities are often missed due to the absence of timely diagnoses. We herein describe a Holographic Assessment of Lymphoma Tissue (HALT) system that adopts a smartphone as the basis for molecular cancer diagnostics. The system detects malignant lymphoma cells labeled with marker-specific microbeads that produce unique holographic signatures. Importantly, we optimized HALT to detect lymphomas in fine-needle aspirates from superficial lymph nodes, procedures that align with the minimally invasive biopsy needs of resource-constrained regions. We equipped the platform to directly address the practical needs of employing novel technologies for "real world" use. The HALT assay generated readouts in <1.5 h and demonstrated good agreement with standard cytology and surgical pathology.

Complete Surgical Excision Is Essential for the Management of Patients With Breast Implant-Associated Anaplastic Large-Cell Lymphoma

PURPOSE

Breast implant-associated anaplastic large-cell lymphoma (BI-ALCL) is a rare type of T-cell lymphoma that arises around breast implants. The optimal management of this disease has not been established. The goal of this study is to evaluate the efficacy of different therapies used in patients with BI-ALCL to determine an optimal treatment approach.

PATIENTS AND METHODS

In this study, we applied strict criteria to pathologic findings, assessed therapies used, and conducted a clinical follow-up of 87 patients with BI-ALCL, including 50 previously reported in the literature and 37 unreported. A Prentice, Williams, and Peterson model was used to assess the rate of events for each therapeutic intervention.

RESULTS

The median and mean follow-up times were 45 and 30 months, respectively (range, 3 to 217 months). The median overall survival (OS) time after diagnosis of BI-ALCL was 13 years, and the OS rate was 93% and 89% at 3 and 5 years, respectively. Patients with lymphoma confined by the fibrous capsule surrounding the implant had better event-free survival (EFS) and OS than did patients with lymphoma that had spread beyond the capsule (P = .03). Patients who underwent a complete surgical excision that consisted of total capsulectomy with breast implant removal had better OS (P = .022) and EFS (P = .014) than did patients who received partial capsulectomy, systemic chemotherapy, or radiation therapy.

CONCLUSION

Surgical management with complete surgical excision is essential to achieve optimal EFS in patients with BI-ALCL.

Impact of oncogene rearrangement patterns on outcomes in patients with double-hit non-Hodgkin lymphoma

BACKGROUND

Double-hit lymphomas (DHLs) are collectively defined as B-cell non-Hodgkin lymphomas harboring rearrangements of MYC as well as B-cell lymphoma 2 (BCL2) and/or B-cell lymphoma 6 (BCL6). To the authors' knowledge, the impact of specific oncogene rearrangements on outcomes of patients with DHL who are treated with immunochemotherapy has not been previously described.

METHODS

The authors identified patients whose diagnostic tissue specimens underwent metaphase karyotyping or fluorescence in situ hybridization for MYC as well as both BCL2 and BCL6 rearrangements. Cohorts were defined by the presence (+) or absence (-) of rearrangements: MYC+/BCL2+/BCL6- (BCL2-DHL), MYC+/BCL2-/BCL6+ (BCL6-DHL), and MYC+/BCL2+/BCL6+ (triple-hit lymphoma; THL).

RESULTS

A total of 117 patients were included in the current analysis (76 BCL2-DHL patients, 16 BCL6-DHL patients, and 25 THL patients). Compared with patients with BCL2-DHL, those with BCL6-DHL were more likely to be classified as having a non-germinal center cell of origin, presented with extranodal disease, and appeared to achieve higher rates of complete response despite receiving intensive induction therapy less frequently. However, patients with BCL6-DHL experienced a shorter median overall survival if achieving an initial complete response compared with patients with BCL2-DHL. Patients with THL experienced survival outcomes similar to those of patients with BCL2-DHL.

CONCLUSIONS

Recognition of the specific oncogene rearrangements may be of prognostic value and potentially guide future therapeutic strategies for patients with DHL.