De novo pure erythroid leukemia: refining the clinicopathologic and cytogenetic characteristics of a rare entity.

Per the revised fourth edition World Health Organization classification of acute myeloid leukemia, pure erythroid leukemia is now the sole type of acute erythroid leukemia. The diagnosis of this rare entity is often challenging and the cytologic overlap with non-neoplastic (eg, megaloblastic anemia) and neoplastic entities (eg, other types of acute leukemia and non-hematopoietic malignancies) warrants a significant degree of clinical, laboratory, immunophenotypic, and genetic investigation. Given the limited number of reports of this rare and diagnostically challenging entity, we report detailed clinicopathologic characteristics from 15 patients, the largest series thus far, of primary de novo pure erythroid leukemia to provide further diagnostic insights into this entity and reveal strategies for making the diagnosis. We found that de novo pure erythroid leukemia is a disease of adults (median age 68 years), exhibits a striking male predominance, is universally associated with an abnormal karyotype and has an exceedingly poor overall median survival of 1.4 months. Given the general inability of immunophenotypic markers to discriminate neoplastic from non-neoplastic erythroid proliferations, key features identified in this study to help establish the diagnosis of pure erythroid leukemia and exclude mimickers include circulating pronormoblasts, clear-cut dysplasia in erythroid, granulocytic, and/or megakaryocytic lineage, utilization of a broad immunophenotypic panel, TP53 immunohistochemical positivity, and identification of a complex, often highly complex, karyotype. Given the gravity of a diagnosis of de novo pure erythroid leukemia, it should be rendered with utmost confidence.

Implementation of and Systems-Level Barriers to Guideline-Driven Germline Genetic Evaluation in the Care of Patients With Myelodysplastic Syndrome and Acute Myeloid Leukemia.

PURPOSE: Knowledge of an inherited predisposition to myelodysplastic syndrome (MDS) and AML has important clinical implications for treatment decisions, surveillance, and care of at-risk relatives. National Comprehensive Cancer Network (NCCN) guidelines recently incorporated recommendations for germline genetic evaluation of patients with MDS/AML on the basis of personal and family history features, but the practicality of implementing these recommendations has not been studied. METHODS: A hereditary hematology quality improvement (QI) committee was formed to implement these guidelines in a prospective cohort of patients diagnosed with MDS/AML. Referral for germline genetic testing was recommended for patients meeting NCCN guideline criteria. Referral patterns and genetic evaluation outcomes were compared with a historical cohort of patients with MDS/AML. Barriers to evaluation were identified. RESULTS: Of the 90 patients with MDS/AML evaluated by the QI committee, 59 (66%) met criteria for germline evaluation. Implementation of the QI committee led to more referrals for germline evaluation in accordance with NCCN guidelines (31% v 14%, P = .03). However, the majority of those meeting criteria were never referred due to high medical acuity or being deceased or in hospice at the time of QI committee recommendations. Despite this, two (17%) of the 12 patients undergoing genetic testing were diagnosed with a hereditary myeloid malignancy syndrome. CONCLUSION: Current NCCN guidelines resulted in two thirds of patients with MDS/AML meeting criteria for germline evaluation. A hereditary hematology-focused QI committee aided initial implementation and modestly improved NCCN guideline adherence. However, the high morbidity and mortality and prolonged inpatient stays associated with MDS/AML challenged traditional outpatient genetic counseling models. Further improvements in guideline adherence require innovating new models of genetic counseling and testing for this patient population.

Neighborhood disadvantage, insurance status, and molecular profiling of patients with acute myeloid leukemia.

Next-generation sequencing (NGS) is important for prognostication and determining eligibility for targeted therapies in acute myeloid leukemia (AML). The use of NGS has increased in clinical practice, but variability in testing patterns still exist. The purpose of this study was to assess trends in molecular genetic sequencing in AML based on insurance status and area deprivation index (ADI), a validated metric of neighborhood disadvantage. Patient demographics, clinical characteristics, cytogenetic and molecular data, and treatment patterns were collected retrospectively for 275 patients diagnosed with AML at a single institution. No significant differences in practice patterns and patient outcomes based on ADI rank were observed. In contrast, patients with Medicare or underinsured status were less likely to have genetic sequencing performed, were treated with less intensive regimens, and had inferior overall survival compared to those with Medicaid or private insurance. On univariate analysis, molecular genetic sequencing was associated with improved overall survival, suggesting that NGS data allows for better risk stratification and more informed therapeutic decision-making. These data highlight the current barriers to molecular genetic sequencing, demonstrate the positive benefits of NGS on clinical outcomes, and support universal coverage of NGS for all patients with AML.

Needle in a haystack or elephant in the room? Identifying germline predisposition syndromes in the setting of a new myeloid malignancy diagnosis.

Myeloid malignancies associated with germline predisposition syndromes account for up to 10% of myeloid neoplasms. They are classified into three categories by the proposed 5th Edition of the World Health Organization Classification of Hematolymphoid Tumors: (1) neoplasms with germline predisposition without a pre-existing platelet disorder or organ dysfunction, (2) neoplasms with germline predisposition and pre-existing platelet disorder, or (3) neoplasms with germline predisposition and potential organ dysfunction. Recognizing these entities is critical because patients and affected family members benefit from interfacing with hematologists who specialize in these disorders and can facilitate tailored treatment strategies. However, identification of these syndromes in routine pathology practice is often challenging, as characteristic findings associated with these diagnoses at baseline are frequently absent, nonspecific, or impossible to evaluate in the setting of a myeloid malignancy. Here we review the formally classified germline predisposition syndromes associated with myeloid malignancies and summarize practical recommendations for pathologists evaluating a new myeloid malignancy diagnosis. Our intent is to empower clinicians to better screen for germline disorders in this common clinical setting. Recognizing when to suspect a germline predisposition syndrome, pursue additional ancillary testing, and ultimately recommend referral to a cancer predisposition clinic or hematology specialist, will ensure optimal patient care and expedite research to improve outcomes for these individuals.

Immunohistochemistry for LEF1 and SOX11 adds diagnostic specificity in small B-cell lymphomas.

Lymphocyte enhancer-binding factor 1 (LEF1) and SRY-Box 11 (SOX11) are highly sensitive and specific for chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and mantle cell lymphoma (MCL) including the cyclin D1-negative subtype, respectively. We assessed the utility of these markers in a large cohort of small B-cell lymphomas (SBCLs) on varied sample types. Immunohistochemistry (IHC) was performed for LEF1 and SOX11 on 354 SBCLs (129 CLL/SLLs, 33 MCLs, 142 marginal zone lymphomas [MZLs]-nodal MZL [NMZL]: 40, extranodal MZL [ENMZL]: 28, splenic MZL [SMZL]: 74 cases-and 50 lymphoplasmacytic lymphomas [LPLs]/Waldenstrom macroglobulinemias [WMs]). Ninety-eight percent of CLL/SLLs were LEF1 positive. SOX11 showed good sensitivity (82%) and excellent specificity for MCL (99%), with only 2 of 142 MZLs (both SMZLs) showing SOX11 expression. The low sensitivity for SOX11 was on account of inclusion of 4 non-nodal cases. All 50 LPL/WMs were negative for both LEF1 and SOX11. The expression of SOX11 and LEF1 was not always mutually exclusive, as 2 confirmed MCLs expressed both markers. LEF1 and SOX11 have excellent utility as diagnostic markers especially for atypical CD5-positive SBCLs.

Clinical utility and real-world application of molecular genetic sequencing in the management of patients with acute myeloid leukemia and myelodysplastic syndromes.

Recurrently mutated genes in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) have proven useful in risk stratification and clinical decision-making. Sequencing technologies that detect these genetic mutations are now widely available, though there is variability in the use of such data among hematologists. Molecular genetic sequencing trends were assessed in 470 patients presenting to a single institution with AML or MDS to determine how molecular data impacts clinical management of patients with myeloid malignancies. Patients with AML were more likely to have molecular genetic sequencing performed compared to patients with MDS, and clinicians were more likely to reference molecular data in decision-making for patients with AML. Furthermore, the presence of molecular data was associated with an increased odd of bone marrow transplantation (BMT). This study demonstrates the real-world application of molecular data in the management of myeloid malignancies and also highlights disparities in the use of such data based on diagnosis.

A Case of Isolated Myeloid Sarcoma Associated With Germline EGFR T790M Variant: The Importance of Recognizing Potential Germline Variants on Somatic Tumor Sequencing Panels.

Isolated myeloid sarcoma is an uncommon subtype of acute myeloid leukemia associated with variable prognosis. We present the case of a previously healthy 30-year-old man presenting with chest pain and weight loss who was found to have a large mediastinal mass. Biopsy of the mass was consistent with isolated myeloid sarcoma. A somatic tumor sequencing panel revealed an EGFR T790M variant, which was later confirmed to be of germline origin. Germline EGFR T790M variants are associated with a hereditary predisposition to lung cancer, though myeloid malignancies have not yet been described. To our knowledge, this is the first reported case of myeloid sarcoma in a patient with an underlying germline EGFR T790M mutation. As somatic tumor sequencing panels become more commonplace, it is important to recognize potential germline variants in order to facilitate appropriate referral for genetic counseling, perform confirmatory genetic testing, and to develop a personalized treatment and surveillance plan for patients and their families.

Pink pigtail in a skin biopsy: What is your diagnosis?

Sarcoptes scabiei is an obligate ectoparasite, which burrows into the stratum granulosum of the epidermis and lays its eggs. The resultant host inflammatory response leads to intensely pruritic papules. CASE SYNOPSIS: A 63-year-old man undergoing treatment for immunoproliferative disease was suspected of having a pruritic drug eruption. Subsequent skin biopsy revealed an intracorneal burrow containing three pink, refractile pigtail-like structures, believed to be empty eggshells of S. scabiei. CONCLUSION: Traditionally, the presence of adult mites or eggs in skin scrapings or a skin biopsy is required for a definitive diagnosis of scabies. However, our case and similar cases suggest that the diagnosis of scabies can also be made on the basis of pink pigtail-like structures, remnants of eggshells, within the intracorneal burrow.

Gastrointestinal cancers: current biomarkers in esophageal and gastric adenocarcinoma.

Esophageal and gastric adenocarcinomas are frequently diagnosed at an advanced stage and have a dismal prognosis. Even in patients with potentially curative cancer, nearly 50% will develop recurrent disease despite aggressive treatments. A number of biomarkers currently guide treatment decisions for patients with esophageal and gastric adenocarcinoma and include human epidermal growth factor receptor 2 (HER2) amplification, mismatch repair deficiency/microsatellite instability (dMMR/MSI-H) and program death-ligand 1 (PD-L1) expression. This review will focus on the function, testing and FDA-approved targeted therapies for HER2, dMMR/MSI-H and PD-L1. In addition, a number of novel targets in esophageal and gastric cancer are being studied in clinical trials. Neurotrophic-tropomyosin receptor kinase (NTRK), claudin-18 (CLDN18)/Rho GTPase activating protein 26 (ARHGAP26) gene fusion, fibroblast growth factor receptor (FGFR), lymphocyte-activation gene 3 (LAG3) and T cell immunoglobulin and mucin-domain containing-3 (TIM3) will be briefly reviewed. Despite several biomarkers used in the selection of treatment therapies, treatment outcomes remain poor. Future research efforts will focus on the identification of new biomarkers, moving existing biomarkers into earlier lines of therapy, and evaluating new combinations of existing biomarkers and therapies.

Targeted Next-Generation Sequencing in Myelodysplastic Syndrome and Chronic Myelomonocytic Leukemia Aids Diagnosis in Challenging Cases and Identifies Frequent Spliceosome Mutations in Transformed Acute Myeloid Leukemia.

OBJECTIVES: Optimal integration of next-generation sequencing (NGS) into clinical practice in hematologic malignancies remains unclear. We evaluate the utility of NGS in myeloid malignancies. METHODS: A 42-gene panel was used to sequence 109 cases of myelodysplastic syndrome (MDS, n = 38), chronic myelomonocytic leukemia (CMML, n = 14), myeloproliferative neoplasm (MPN, n = 24), and MDS and/or MPN transformed to acute myeloid leukemia (AML, n = 33). RESULTS: At least one pathogenic mutation was identified in 74% of cases of MDS, 100% of CMMLs, and 96% of MPNs. In contrast, only 47% of cases of MDS (18/38) and 7% (1/14) of CMMLs exhibited abnormal cytogenetics. In diagnostically difficult cases of MDS or CMML with normal cytogenetics, NGS identified a pathogenic mutation and was critical in establishing the correct diagnosis. Spliceosomal genes and epigenetic modifiers were frequently mutated. Spliceosome mutations were also frequently detected in AML arising from MDS, CMML, or MPN (39%) compared with the reported rate in de novo AML (7%-14%). CONCLUSIONS: In difficult cases of MDS or MPN, NGS facilitates diagnosis by detection of gene mutations to confirm clonality, and AMLs evolving from MDS or MPN carry frequent mutations in spliceosomal genes.

How to submit a nail specimen.

The scarcity of specific submission protocols for nail unit biopsies presents many challenges for appropriate specimen processing. Many nail biopsies are received fragmented or without orientation, often resulting in less-than-ideal tissue embedding and poor histologic sections, which are difficult to interpret. Methods are described for proper nail matrix/bed biopsy and plate submission that incorporate aspects of previous submission protocols and include inking the biopsy specimen along with submitting the tissue on a drawing of the nail. Also described is a technique for maintaining adherence of nail plate to glass slides, a chronic challenge in the laboratory.

Assessing copy number alterations in targeted, amplicon-based next-generation sequencing data.

Changes in gene copy number are important in the setting of precision medicine. Recent studies have established that copy number alterations (CNAs) can be detected in sequencing libraries prepared by hybridization-capture, but there has been comparatively little attention given to CNA assessment in amplicon-based libraries prepared by PCR. In this study, we developed an algorithm for detecting CNAs in amplicon-based sequencing data. CNAs determined from the algorithm mirrored those from a hybridization-capture library. In addition, analysis of 14 pairs of matched normal and breast carcinoma tissues revealed that sequence data pooled from normal samples could be substituted for a matched normal tissue without affecting the detection of clinically relevant CNAs (>|2| copies). Comparison of CNAs identified by array comparative genomic hybridization and amplicon-based libraries across 10 breast carcinoma samples showed an excellent correlation. The CNA algorithm also compared favorably with fluorescence in situ hybridization, with agreement in 33 of 38 assessments across four different genes. Factors that influenced the detection of CNAs included the number of amplicons per gene, the average read depth, and, most important, the proportion of tumor within the sample. Our results show that CNAs can be identified in amplicon-based targeted sequencing data, and that their detection can be optimized by ensuring adequate tumor content and read coverage.