Implementation and Evaluation of Virtual Laboratory Tours for Laboratory Diagnosis of Hematologic Disease.

OBJECTIVES: There is often limited time allocated to teaching laboratory medicine to medical students. Without adequate time and context, it can be difficult for students to learn appropriate uses and limitations of laboratory tests. Introducing students to the laboratories and test methods may help them learn these concepts, but physical laboratory tours are difficult to organize for large groups, especially during the coronavirus disease 2019 pandemic. METHODS: We created virtual laboratory tours consisting of short video clips and voiceover PowerPoint slides to teach students about the laboratory tests used to diagnose hematologic malignancies. We assessed the impact on student performance on laboratory medicine-themed quiz questions and surveyed the students to determine their attitudes about the activity. RESULTS: In total, 129 first-year medical students participated in the study. The average score on the preactivity quiz was 59.8%, and the average score on the postactivity quiz was 92.2%. Students were more confident in their ability to answer quiz questions after completing the activity. Postactivity survey data indicated that the students enjoyed the activity and felt it was an effective way to learn the material. CONCLUSIONS: Virtual laboratory tours show promise as a method of incorporating more laboratory medicine content into medical school curricula.

A Case of Cyclic Neutropenia and Associated Amyloidosis.

Cyclic neutropenia has been rarely associated with chronic inflammation and development of reactive AA amyloidosis. We report a family with cyclic neutropenia with associated renal and thyroid amyloid. A 12-year-old female presented with thyromegaly, recurrent aphthous ulcers, severe neutropenia, and renal failure. Renal and thyroid biopsies revealed abundant amyloid deposition. Presence of a heterozygous ELANE c.358 A>T gene mutation p.I120F variant with autosomal dominant inheritance confirmed the diagnosis of cyclic neutropenia. The patient's father also had neutropenia and amyloidosis with renal failure. We started filgrastim to attenuate neutropenia and thereby reduce chronic inflammation and minimize further amyloid deposition.

IDH1 mutated acute myeloid leukemia in a child with metaphyseal chondromatosis with D-2-hydroxyglutaric aciduria.

D-2-hydroxyglutaric aciduria (D-2-HGA) is a rare metabolic disorder characterized by developmental delay, hypotonia, and bi-allelic mutations in D-2-hydroxyglutarate dehydrogenase (D2HGDH) or a single gain-of-function mutation in isocitrate dehydrogenase 2 (IDH2). Metaphyseal chondromatosis with D-2-hydroxyglutaric aciduria (MC-HGA) is a type of D-2-HGA that has been previously reported in ten patients (OMIM 614875), three of whom had somatic mosaicism for R132 variants in isocitrate dehydrogenase 1 (IDH1). We describe a 3-year-old boy with MC-HGA who subsequently developed acute myeloid leukemia (AML) and was found to have an IDH1 R132C mutation in a leukemic bone marrow sample. Further testing revealed presence of somatic mosaicism for IDH1 R132C variant, suggesting an association of IDH1 in inducing myeloid leukemogenesis.

Chronic myeloid leukemia manifested as myeloid sarcoma: Review of literature and case report.

In this report, we present the case of a 50-year-old woman presenting with an intraparenchymal myeloid sarcoma manifesting as weakness. She has a history of chronic myeloid leukemia (CML) treated with imatinib not taken consistently with a relapse to blast crisis, and then an isolated relapse as a myeloid sarcoma manifesting as facial and extremity weakness. An MRI of the brain showed an enhancing, well-circumscribed mass within the frontal lobe with edema extending to the motor strip. Based on tumor size, focality, location, growth rate, and patient's symptoms, surgeons determined that the patient should undergo surgical resection. Postoperatively, the patient had full resolution of her acute neurological symptoms without post-operative complications. Post-operative MRI showed minimal enhancement suggesting post-surgical changes vs minimal residual tumor. The patient was scheduled to undergo whole brain radiotherapy with supplemental direct radiation to the site of resection. This is the first report of safe and complete resection of an intraparenchymal myeloid sarcoma. It is meant to inform neurosurgeons that brain tumors can be potentially CML-related; additionally, we review CML's manifestations in the central nervous system and how neurosurgeons can consider optimal management given as there are no guidelines on how to treat CML-related CNS disease.

Kikuchi-Fujimoto Disease: An Atypical Presentation of a Rare Disease.

Kikuchi-Fujimoto disease (KFD), or necrotizing histiocytic lymphadenitis, is a rare cause of lymphadenopathy and fever. Although the clinical course is usually benign, KFD is often mistaken for malignancy or infection. Recognition of typical and atypical cases of KFD is necessary to avoid unnecessary interventions. Here we report an atypical presentation of KFD with diffuse lymphadenopathy and leukocytosis associated with high levels of circulating Epstein-Barr viral DNA.

Simultaneous B and T cell acute lymphoblastic leukemias in zebrafish driven by transgenic MYC: implications for oncogenesis and lymphopoiesis.

Precursor-B cell acute lymphoblastic leukemia (pre-B ALL) is the most common pediatric cancer, but there are no useful zebrafish pre-B ALL models. We describe the first highly- penetrant zebrafish pre-B ALL, driven by human MYC. Leukemias express B lymphoblast-specific genes and are distinct from T cell ALL (T-ALL)-which these fish also develop. Zebrafish pre-B ALL shares in vivo features and expression profiles with human pre-B ALL, and these profiles differ from zebrafish T-ALL or normal B and T cells. These animals also exhibit aberrant lymphocyte development. As the only robust zebrafish pre-B ALL model and only example where T-ALL also develops, this model can reveal differences between MYC-driven pre-B vs. T-ALL and be exploited to discover novel pre-B ALL therapies.

Molecular and cellular genetics of non-Hodgkin lymphoma: Diagnostic and prognostic implications.

Non-Hodgkin lymphoma (NHL) is a diverse collection of malignant neoplasms with lymphoid-cell origin which includes all the malignant lymphomas that are not classified as Hodgkin lymphoma. NHL is one of the most common types of cancer diagnosed in men and women in the developed world. In the United States of America, the past few decades have seen a significant rise in the incidence of NHL and it accounts for about 4% of all cancers now. The overall survival of NHL has improved drastically over the past ten years. This can be attributed to better understanding of pathogenesis, refined classification, enhanced supportive care, and data from collaborative clinical trials. The prognosis of a newly diagnosed NHL patient depends, among other factors, on the specific subtype of lymphoma, stage of the disease, and age of the patient. Advances in the fields of molecular biology and innovations in cytogenetic techniques have led to the discovery of several oncogenic pathways involved in lymphomagenesis, which in turn has amplified the diagnostic and therapeutic approaches available for NHL. Our comprehension of the genetic features that determine the character of NHL, and ultimately guide the therapy, has undergone significant shift and it is essential that scientists as well as clinicians stay in tune with this rapidly evolving knowledge. In this review we have summarized the current concepts about cellular and molecular genetics of the common subtypes of NHL and their clinical implications.

Drug-Induced Hypersensitivity Syndrome: A Clinical, Radiologic, and Histologic Mimic of Lymphoma.

Drug-induced hypersensitivity syndrome (DIHS; also known as drug reaction with eosinophilia and systemic symptoms, or DRESS) is a rare, potentially life-threatening condition that typically presents 2-8 weeks after drug exposure with fever, rash, organ dysfunction, and lymphadenopathy. Here, we describe the case of an 18-year-old African American female who presented with cervical lymphadenopathy, fevers, and a macular rash. A PET scan showed diffuse hypermetabolic lymphadenopathy suggestive of lymphoma, with involvement of the spleen and kidneys. The clinical history, imaging, and biopsy findings initially raised concern for a malignant process, with a differential diagnosis including classic Hodgkin's lymphoma and T-cell lymphoma. However, the morphologic and immunophenotypic features were not entirely typical for those diagnoses. The patient was ultimately diagnosed with DIHS after it was learned that she recently had been treated with minocycline, a medication previously implicated in causing DIHS.

Evidence of Alternative Modes of B Cell Activation Involving Acquired Fab Regions of N-Glycosylation in Antibody-Secreting Cells Infiltrating the Labial Salivary Glands of Patients With Sjögren's Syndrome.

OBJECTIVE: To better understand the role of B cells, the potential mechanisms responsible for their aberrant activation, and the production of autoantibodies in the pathogenesis of Sjögren's syndrome (SS), this study explored patterns of selection pressure and sites of N-glycosylation acquired by somatic mutation (acN-glyc) in the IgG variable (V) regions of antibody-secreting cells (ASCs) isolated from the minor salivary glands of patients with SS and non-SS control patients with sicca symptoms. METHODS: A novel method to produce and characterize recombinant monoclonal antibodies (mAb) from single cell-sorted ASC infiltrates was applied to concurrently probe expressed genes (all heavy- and light-chain isotypes as well as any other gene of interest not related to immunoglobulin) in the labial salivary glands of patients with SS and non-SS controls. V regions were amplified by reverse transcription-polymerase chain reaction, sequenced, and analyzed for the incidence of N-glycosylation and selection pressure. For specificity testing, the amplified regions were expressed as either the native mAb or mutant mAb lacking the acN-glyc motif. Protein modeling was used to demonstrate how even an acN-glyc site outside of the complementarity-determining region could participate in, or inhibit, antigen binding. RESULTS: V-region sequence analyses revealed clonal expansions and evidence of secondary light-chain editing and allelic inclusion, of which neither of the latter two have previously been reported in patients with SS. Increased frequencies of acN-glyc were found in the sequences from patients with SS, and these acN-glyc regions were associated with an increased number of replacement mutations and lowered selection pressure. A clonal set of polyreactive mAb with differential framework region 1 acN-glyc motifs was also identified, and removal of the acN-glyc could nearly abolish binding to autoantigens. CONCLUSION: These findings support the notion of an alternative mechanism for the selection and proliferation of some autoreactive B cells, involving V-region N-glycosylation, in patients with SS.

Imaging of subclinical haemopoiesis after stem-cell transplantation in patients with haematological malignancies: a prospective pilot study.

BACKGROUND: Haemopoietic stem-cell transplantation (HSCT) eradicates host haemopoiesis before venous infusion of haemopoietic stem cells (HSCs). The pathway to cellular recovery has been difficult to study in human beings because of risks associated with interventions during aplasia. We investigated whether 18F-fluorothymidine (18F-FLT) imaging was safe during allogenic HSCT and allowed visualisation of early cellular proliferation and detection of patterns of cellular engraftment after HSCT. METHODS: Eligible patients were aged 18-55 years, had high-risk haematological malignancies. All patients underwent myeloablation followed by HSCT. The imaging primary endpoint was detection of early subclinical engraftment after HSCT with 18F-FLT PET or CT. Imaging was done 1 day before and 5 or 9, and 28 days, and 1 year after HSCT. This study is registered with ClinicalTrials.gov, number NCT01338987. FINDINGS: Between April 1, 2014, and Dec 31, 2015, 23 patients were enrolled and assessable for toxic effects after completing accrual. 18F-FLT was not associated with any adverse events or delayed engraftment. 18F-FLT imaging objectively identified subclinical bone-marrow recovery within 5 days of HSC infusion, which was up to 20 days before engraftment became clinically evident. Quantitatively, 18F-FLT intensity differed significantly between myeloablative infusion before HSCT and subclinical HSC recovery (p=0·00031). 18F-FLT biodistribution over time revealed a previously unknown path of cellular recovery of haemopoiesis in vivo that mirrored fetal ontogeny. INTERPRETATION: 18F-FLT allowed quantification and tracking of subclinical bone-marrow repopulation in human beings and revealed new insights into the biology of HSC recovery after HSCT. FUNDING: National Institutes of Health, Ben's Run/Ben's Gift, Albert and Elizabeth Tucker Foundation, Mex Frates Leukemia Fund, Jones Family fund, and Oklahoma Center for Adult Stem Cell Research.

Non-seminomatous mediastinal germ cell tumor and acute megakaryoblastic leukemia.

The association between mediastinal germ cell tumors (MGCT) and acute megakaryoblastic (M7) leukemia has been known for many years. We hereby present this review to better characterize the coexistence of these entities as well as the salient features, the treatment options, and the overall prognosis. A search of PUBMED, Medline, and EMBASE databases via OVID engine for primary articles and case reports under keywords "germ cell tumors" and "acute myeloid leukemia" revealed a total of 26 cases in English that reported MGCT and M7 leukemia. The median age at diagnosis of MGCT was 24 (13-36) years. All cases were stage III. All cases of MGCT were of non-seminomatous origin and one case was unclassified. MGCT occurred prior to the diagnosis of leukemia in 46% of cases and concomitantly in 31% of cases. M7 leukemia was never reported prior to the appearance of MGCT. Complex cytogenetics and hyperdiploidy were the most commonly reported cytogenetic abnormalities. In the 23 cases where the treatment regimen was available, platinum-based chemotherapy directed towards management of the germ cell tumors was used initially in 21 cases and leukemia-directed treatment was used initially in 2 cases only. The median time from diagnosis of MGCT to development of M7 leukemia was 5 (2.25-39) months. Median time to death from the initial diagnosis of MGCT was 6 (0.5-60) months. Patients with a history of MGCT are at higher risk of developing M7 leukemia. They need long-term follow-up with a particular attention to the development of hematological malignancies. The overall prognosis remains poor.

A Case of p63 Positive Diffuse Large B Cell Lymphoma of the Bladder.

Diffuse large B cell lymphoma (DLBCL), currently the most common type of non-Hodgkin lymphoma (NHL), is an aggressive B cell neoplasm that typically presents in older adults as a rapidly enlarging mass. The enlarging mass typically represents a lymph node, although extranodal disease can occur in a significant percentage (40%) of cases. The most common extranodal sites of involvement include the gastrointestinal tract and skin; primary bladder lymphoma represents only 0.2% of extranodal non-Hodgkin lymphomas. We report a case of diffuse large B cell lymphoma occurring in the bladder of an 83-year-old gentleman with an initial presentation of hematuria. This neoplasm displayed large, atypical cells with vesicular chromatin and prominent nucleoli that involved the bladder mucosa with invasion into muscularis propria, prostate, and urethra. Positive staining for p63 initially raised suspicion for poorly differentiated urothelial carcinoma; however, lack of staining for pancytokeratin and positive staining for LCA, CD20, CD79a, and PAX-5 confirmed the diagnosis of diffuse large B cell lymphoma. Though it does not occur in all cases, p63 can be positive in a significant percentage of cases of DLBCL; therefore, a diagnosis of lymphoma remains an important entity on the differential diagnosis of aggressive and particularly poorly differentiated neoplasms.