Abstract Richter transformation (RT) is defined as the transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) into high-grade lymphoma. An average of 5% of patients with CLL/SLL will have disease that undergoes RT during their clinical course. While most (75%) of these transformed cases manifest as diffuse large B-cell lymphoma, other variants occur, including a small minority (0.4%–0.7%) that progress to a classic Hodgkin lymphoma variant. Richter transformation portends a poor outcome in comparison to nontransformed CLL/SLL. Allogeneic stem cell transplantation (allo-SCT) can be offered, with a 5-year survival rate of 50% to 70%. In addition to disease relapse, transplantation carries significant risk of nonrelapse morbidity, including posttransplant lymphoproliferative disorder (PTLD). The distinction between disease progression or recurrence and PTLD can be challenging and has critical prognostic and therapeutic implications. In this report, we describe a patient whose initial CLL/SLL transformed to diffuse large B-cell lymphoma, who then received allo-SCT. Subsequent development of classic Hodgkin lymphoma proved to be a diagnostic conundrum, for which PTLD and disease progression/recurrence were both reasonable considerations. This case illustrates the diagnostic dilemma and semantic confusion faced by both pathologists and clinicians when lymphoproliferative disorders emerge within the immunologically complex interface of CLL/SLL, RT, and allo-SCT. As molecular technologies are becoming more commonplace in routine diagnostics, subpopulation clonal analysis may be useful in such cases. It may also be worth reevaluating the classification and criteria for PTLD and different subtypes of RT, especially in light of implications for prognosis and optimal therapies.

Background Jumping translocations (JTs) are rare chromosome rearrangements characterized by re-localization of one donor chromosome to multiple recipient chromosomes. Here, we describe an acute myeloid leukemia (AML) that progressed from myelodysplastic syndrome (MDS) in association with acquisition of 1q JTs. The sequence of molecular and cytogenetic changes in our patient may provide a mechanistic model for the generation of JTs in leukemia. Case presentation A 68-year-old man presented with pancytopenia. Bone marrow aspirate and biopsy showed a hypercellular marrow with multilineage dysplasia, consistent with MDS, with no increase in blasts. Karyotype and MDS fluorescence in situ hybridization (FISH) panel were normal. Repeat bone marrow aspirate and biopsy after 8 cycles of azacitidine, with persistent pancytopenia, showed no changes in morphology, and karyotype was again normal. Myeloid mutation panel showed mutations in RUNX1 , SRSF2 , ASXL1 , and TET2 . Three years after diagnosis, he developed AML with myelodysplasia-related changes. Karyotype was abnormal, with unbalanced 1q JTs to the short arms of acrocentric chromosomes 14 and 21, leading to gain of 1q. Conclusions Our patient had MDS with pathogenic mutations of the RUNX1 , SRSF2 , ASXL1 , and TET2 genes and developed 1q JTs at the time of progression from MDS to AML. Our data suggest that the formation of 1q JTs involves multiple stages and may provide a mechanistic model for the generation of JTs in leukemia.

The recent Zika virus (ZIKV) outbreak in the Americas surprised all of us because of its rapid spread and association with neurologic disorders including fetal microcephaly, brain and ocular anomalies, and Guillain–Barré syndrome. In response to this global health crisis, unprecedented and world-wide efforts are taking place to study the ZIKV-related human diseases. Much has been learned about this virus in the areas of epidemiology, genetic diversity, protein structures, and clinical manifestations, such as consequences of ZIKV infection on fetal brain development. However, progress on understanding the molecular mechanism underlying ZIKV-associated neurologic disorders remains elusive. To date, we still lack a good understanding of; (1) what virologic factors are involved in the ZIKV-associated human diseases; (2) which ZIKV protein(s) contributes to the enhanced viral pathogenicity; and (3) how do the newly adapted and pandemic ZIKV strains alter their interactions with the host cells leading to neurologic defects? The goal of this review is to explore the molecular insights into the ZIKV–host interactions with an emphasis on host cell receptor usage for viral entry, cell innate immunity to ZIKV, and the ability of ZIKV to subvert antiviral responses and to cause cytopathic effects. We hope this literature review will inspire additional molecular studies focusing on ZIKV–host Interactions.

The recent Zika virus (ZIKV) outbreak in the Americas surprised all of us because of its rapid spread and association with neurologic disorders including fetal microcephaly, brain and ocular anomalies, and Guillain⁻Barré syndrome. In response to this global health crisis, unprecedented and world-wide efforts are taking place to study the ZIKV-related human diseases. Much has been learned about this virus in the areas of epidemiology, genetic diversity, protein structures, and clinical manifestations, such as consequences of ZIKV infection on fetal brain development. However, progress on understanding the molecular mechanism underlying ZIKV-associated neurologic disorders remains elusive. To date, we still lack a good understanding of; (1) what virologic factors are involved in the ZIKV-associated human diseases; (2) which ZIKV protein(s) contributes to the enhanced viral pathogenicity; and (3) how do the newly adapted and pandemic ZIKV strains alter their interactions with the host cells leading to neurologic defects? The goal of this review is to explore the molecular insights into the ZIKV⁻host interactions with an emphasis on host cell receptor usage for viral entry, cell innate immunity to ZIKV, and the ability of ZIKV to subvert antiviral responses and to cause cytopathic effects. We hope this literature review will inspire additional molecular studies focusing on ZIKV⁻host Interactions.

A 74-YEAR-OLD WOMAN presented without symptoms to her primary care physician for an annual physical examination. She had a history of type II diabetes mellitus, hypertension, tobacco use, and dyslipidemia. A urinalysis revealed microscopic hematuria, and a screening electrocardiogram showed poor R-wave progression. Transthoracic echocardiography revealed a mobile, solid mass (approximately 1.3 cm by 1.2 cm) in her right atrium. Subcostal views demonstrated the presence of the mass in the inferior vena cava (IVC), but the mass appeared to have originated from the right atrium. The patient was referred for transesophageal echocardiography (TEE) to better define the mass, and TEE was suggestive of a right atrial myxoma. The patient subsequently was referred to a cardiothoracic surgeon for a myxoma resection.

Background: The incidence of MM is 2 to 3 fold higher in blacks than in whites; they present at a younger age and have better overall survival. The biological bases for these disparities remain unclear. Outcome of MM is linked to cytogenetic and molecular changes, both primary (hyperdiploidy and heavy chain (IgH) translocations) and secondary (rearrangements of MYC, activating mutations of NRAS, KRAS or BRAF, and deletions of 17p).