Feasibility of fine needle aspiration for diagnosis of b-cell lymphoma of the thyroid: a case series and review of the literature.

BACKGROUND: Primary thyroid lymphoma (PTL) is a rare cancer accounting for approximately 5% of thyroid malignancies. Historically, incisional biopsy has been the gold standard for definitive diagnosis of PTL, however, the use of cell block as an adjunct to fine needle aspiration (FNA) provides a high sensitivity and specificity for diagnosis and classification. METHODS: Three patients presented with a symptomatic enlarging thyroid mass. Patient 1 underwent incisional biopsy under general anesthesia, Patient 2 underwent core needle biopsy to avoid high risk intubation, and Patient 3 underwent fine needle aspiration alone with the use of cell block. RESULTS: All patients were diagnosed with a fully classified non-Hodgkin's lymphoma using immunohistochemistry, flow cytometry, and fluorescence in situ hybridization (FISH) analysis. CONCLUSIONS: FNA for diagnosis of some subtypes of PTL is feasible and preferred in cases that are particularly high risk for general anesthesia. This minimally invasive technique is safe and cost effective as it avoids expenses associated with operative intervention.

Assessing the role of ultrasound for the evaluation of adult neck masses.

Objectives: The American Academy of Otolaryngology clinical practice guidelines recommend cross-sectional imaging or fine needle aspiration for any neck mass in an adult that persists beyond 2 weeks that is not convincingly related to a bacterial infection. We aimed to assess the role of ultrasound in the evaluation and management of neck masses. Methods: A retrospective chart review was performed of adult patients evaluated in the Otolaryngology clinic at a single institution from December 2014 to December 2015 for a visible or palpable neck mass persistent beyond 2 weeks who had an ultrasound exam as part of their initial workup. Patients with a history of head and neck malignancy or those presenting wtih primary salivary or thyroid gland lesions were excluded. Sonographic features, demographics, imaging, and biopsy results were recorded. Results: Of the 56 patients who met inclusion criteria, 36 (64.3%) received FNA or biopsy, of which 18 (50%) demonstrated malignant pathology. Twenty patients (35.7%) demonstrated benign features on ultrasound and did not undergo tissue sampling. Two of these 20 patients underwent subsequent cross-sectional imaging. Eight of these 20 patients were followed with serial ultrasound with an average of 3 exams over 14.7 months. The remaining 12 patients had spontaneous resolution of their adenopathy. None of these 20 patients was subsequently diagnosed with malignancy. Conclusion: In this study, approximately one third of patients presenting with a visible or palpable neck mass were able to safely avoid cross-sectional imaging and/or tissue sampling when ultrasound demonstrated features consistent with benign pathology. Our results suggest that ultrasound can play a useful role in the initial evaluation and management of adults presenting with a neck mass. Level of Evidence: IV.

Localized modulation of DNA supercoiling, triggered by the Shigella anti-silencer VirB, is sufficient to relieve H-NS-mediated silencing.

In Bacteria, nucleoid structuring proteins govern nucleoid dynamics and regulate transcription. In Shigella spp., at ≤30°C, the histone-like nucleoid structuring protein (H-NS) transcriptionally silences many genes on the large virulence plasmid. Upon a switch to 37°C, VirB, a DNA binding protein and key transcriptional regulator of Shigella virulence, is produced. VirB functions to counter H-NS-mediated silencing in a process called transcriptional anti-silencing. Here, we show that VirB mediates a loss of negative DNA supercoils from our plasmid-borne, VirB-regulated PicsP-lacZ reporter in vivo. The changes are not caused by a VirB-dependent increase in transcription, nor do they require the presence of H-NS. Instead, the VirB-dependent change in DNA supercoiling requires the interaction of VirB with its DNA binding site, a critical first step in VirB-dependent gene regulation. Using two complementary approaches, we show that VirB:DNA interactions in vitro introduce positive supercoils in plasmid DNA. Subsequently, by exploiting transcription-coupled DNA supercoiling, we reveal that a localized loss of negative supercoils is sufficient to alleviate H-NS-mediated transcriptional silencing independently of VirB. Together, our findings provide novel insight into VirB, a central regulator of Shigella virulence and, more broadly, a molecular mechanism that offsets H-NS-dependent silencing of transcription in bacteria.

Localized modulation of DNA supercoiling, triggered by the Shigella anti-silencer VirB, is sufficient to relieve H-NS-mediated silencing.

In Bacteria, nucleoid structuring proteins govern nucleoid dynamics and regulate transcription. In Shigella spp ., at ≤ 30 °C, the histone-like nucleoid structuring protein (H-NS) transcriptionally silences many genes on the large virulence plasmid. Upon a switch to 37 °C, VirB, a DNA binding protein and key transcriptional regulator of Shigella virulence, is produced. VirB functions to counter H-NS-mediated silencing in a process called transcriptional anti-silencing. Here, we show that VirB mediates a loss of negative DNA supercoils from our plasmid-borne, VirB-regulated PicsP-lacZ reporter, in vivo . The changes are not caused by a VirB-dependent increase in transcription, nor do they require the presence of H-NS. Instead, the VirB-dependent change in DNA supercoiling requires the interaction of VirB with its DNA binding site, a critical first step in VirB-dependent gene regulation. Using two complementary approaches, we show that VirB:DNA interactions in vitro introduce positive supercoils in plasmid DNA. Subsequently, by exploiting transcription-coupled DNA supercoiling, we reveal that a localized loss of negative supercoils is sufficient to alleviate H-NS-mediated transcriptional silencing, independently of VirB. Together, our findings provide novel insight into VirB, a central regulator of Shigella virulence and more broadly, a molecular mechanism that offsets H-NS-dependent silencing of transcription in bacteria.

Evaluating the Rising Incidence of Thyroid Cancer and Thyroid Nodule Detection Modes: A Multinational, Multi-institutional Analysis.

Importance: There is epidemiologic evidence that the increasing incidence of thyroid cancer is associated with subclinical disease detection. Evidence for a true increase in thyroid cancer incidence has also been identified. However, a true increase in disease would likely be heralded by an increased incidence of thyroid-referable symptoms in patients presenting with disease. Objectives: To evaluate whether modes of detection (MODs) used to identify thyroid nodules for surgical removal have changed compared with historic data and to determine if MODs vary by geographic location. Design, Setting, and Participants: This was a retrospective analysis of pathology and medical records of 1328 patients who underwent thyroid-directed surgery in 16 centers in 4 countries: 4 centers in Canada, 1 in Denmark, 1 in South Africa, and 12 in the US. The participants were the first 100 patients (or the largest number available) at each center who had thyroid surgery in 2019. The MOD of the thyroid finding that required surgery was classified using an updated version of a previously validated tool as endocrine condition, symptomatic thyroid, surveillance, or without thyroid-referable symptoms (asymptomatic). If asymptomatic, the MOD was further classified as clinician screening examination, patient-requested screening, radiologic serendipity, or diagnostic cascade. Main Outcomes and Measures: The MOD of thyroid nodules that were surgically removed, by geographic variation; and the proportion and size of thyroid cancers discovered in patients without thyroid-referable symptoms compared with symptomatic detection. Data analyses were performed from April 2021 to February 2022. Results: Of the 1328 patients (mean [SD] age, 52 [15] years; 993 [75%] women; race/ethnicity data were not collected) who underwent thyroid surgery that met inclusion criteria, 34% (448) of the surgeries were for patients with thyroid-related symptoms, 41% (542) for thyroid findings discovered without thyroid-referable symptoms, 14% (184) for endocrine conditions, and 12% (154) for nodules with original MOD unknown (under surveillance). Cancer was detected in 613 (46%) patients; of these, 30% (183 patients) were symptomatic and 51% (310 patients) had no thyroid-referable symptoms. The mean (SD) size of the cancers identified in the symptomatic group was 3.2 (2.1) cm (median [range] cm, 2.6 [0.2-10.5]; 95% CI, 2.91-3.52) and in the asymptomatic group, 2.1 (1.4) cm (median [range] cm, 1.7 [0.05-8.8]; 95% CI, 1.92-2.23). The MOD patterns were significantly different among all participating countries. Conclusions and Relevance: This retrospective analysis found that most thyroid cancers were discovered in patients who had no thyroid-referable symptoms; on average, these cancers were smaller than symptomatic thyroid cancers. Still, some asymptomatic cancers were large, consistent with historic data. The substantial difference in MOD patterns among the 4 countries suggests extensive variations in practice.

Metastatic Malignant Paraganglioma Presenting as a Neck Mass Treated with Radiolabeled Somatostatin Analog.

Paragangliomas are rare neuroendocrine tumors that arise from chromaffin-containing tissue. Surgical resection and/or radiation are used for locoregional disease, and reduction of tumor burden with systemic therapy is reserved for metastatic disease. Iobenguane I-131, somatostatin analog (octreotide), and Sunitinib are noncytotoxic options for treatment, while cyclophosphamide, vincristine, and dacarbazine (CVD) and temozolomide are often used as initial chemotherapy options as studies have shown that they offer some tumor response. However, there are no randomized clinical trials demonstrating prolonged survival with the use of chemotherapeutics in metastatic cases. Investigation of alternative therapies that provide survival benefit is thus necessary. We present a case of a 69-year-old female with metastatic malignant paraganglioma presenting as a left parapharyngeal neck mass, which metastasized after surgery, requiring radiation therapy for bony metastasis who was treated with a radioisotope somatostatin analog for disease progression.

A case of secretory carcinoma of the submandibular gland with unusual immunohistochemical staining.

Mammaglobin negative secretory carcinoma may be overlooked. It is important to assess the possibility of diagnosis when histology is suggestive and immunohistochemical staining for S-100 is positive even when staining for mammaglobin is negative.

Closing the Gap Between Mammalian and Invertebrate Peripheral Nerve Injury: Protocol for a Novel Nerve Repair.

BACKGROUND: Outcomes after peripheral nerve injuries are poor despite current nerve repair techniques. Currently, there is no conclusive evidence that mammalian axons are capable of spontaneous fusion after transection. Notably, certain invertebrate species are able to auto-fuse after transection. Although mammalian axonal auto-fusion has not been observed experimentally, no mammalian study to date has demonstrated regenerating axolemmal membranes contacting intact distal segment axolemmal membranes to determine whether mammalian peripheral nerve axons have the intrinsic mechanisms necessary to auto-fuse after transection. OBJECTIVE: This study aims to assess fusion competence between regenerating axons and intact distal segment axons by enhancing axon regeneration, delaying Wallerian degeneration, limiting the immune response, and preventing myelin obstruction. METHODS: This study will use a rat sciatic nerve model to evaluate the effects of a novel peripheral nerve repair protocol on behavioral, electrophysiologic, and morphologic parameters. This protocol consists of a variety of preoperative, intraoperative, and postoperative interventions. Fusion will be assessed with electrophysiological conduction of action potentials across the repaired transection site. Axon-axon contact will be assessed with transmission electron microscopy. Behavioral recovery will be analyzed with the sciatic functional index. A total of 36 rats will be used for this study. The experimental group will use 24 rats and the negative control group will use 12 rats. For both the experimental and negative control groups, there will be both a behavior group and another group that will undergo electrophysiological and morphological analysis. The primary end point will be the presence or absence of action potentials across the lesion site. Secondary end points will include behavioral recovery with the sciatic functional index and morphological analysis of axon-axon contact between regenerating axons and intact distal segment axons. RESULTS: The author is in the process of grant funding and institutional review board approval as of March 2020. The final follow-up will be completed by December 2021. CONCLUSIONS: In this study, the efficacy of the proposed novel peripheral nerve repair protocol will be evaluated using behavioral and electrophysiologic parameters. The author believes this study will provide information regarding whether spontaneous axon fusion is possible in mammals under the proper conditions. This information could potentially be translated to clinical trials if successful to improve outcomes after peripheral nerve injury. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/18706.

Curated multiple sequence alignment for the Adenomatous Polyposis Coli (APC) gene and accuracy of in silico pathogenicity predictions.

Computational algorithms are often used to assess pathogenicity of Variants of Uncertain Significance (VUS) that are found in disease-associated genes. Most computational methods include analysis of protein multiple sequence alignments (PMSA), assessing interspecies variation. Careful validation of PMSA-based methods has been done for relatively few genes, partially because creation of curated PMSAs is labor-intensive. We assessed how PMSA-based computational tools predict the effects of the missense changes in the APC gene, in which pathogenic variants cause Familial Adenomatous Polyposis. Most Pathogenic or Likely Pathogenic APC variants are protein-truncating changes. However, public databases now contain thousands of variants reported as missense. We created a curated APC PMSA that contained >3 substitutions/site, which is large enough for statistically robust in silico analysis. The creation of the PMSA was not easily automated, requiring significant querying and computational analysis of protein and genome sequences. Of 1924 missense APC variants in the NCBI ClinVar database, 1800 (93.5%) are reported as VUS. All but two missense variants listed as P/LP occur at canonical splice or Exonic Splice Enhancer sites. Pathogenicity predictions by five computational tools (Align-GVGD, SIFT, PolyPhen2, MAPP, REVEL) differed widely in their predictions of Pathogenic/Likely Pathogenic (range 17.5-75.0%) and Benign/Likely Benign (range 25.0-82.5%) for APC missense variants in ClinVar. When applied to 21 missense variants reported in ClinVar and securely classified as Benign, the five methods ranged in accuracy from 76.2-100%. Computational PMSA-based methods can be an excellent classifier for variants of some hereditary cancer genes. However, there may be characteristics of the APC gene and protein that confound the results of in silico algorithms. A systematic study of these features could greatly improve the automation of alignment-based techniques and the use of predictive algorithms in hereditary cancer genes.

Myelodysplastic Syndrome with Transfusion Dependence Treated with Venetoclax.

Myelodysplastic syndromes are characterized by ineffective hematopoiesis in one or more lineages of the bone marrow. They are a group of heterogeneous clonal stem cell malignancies with a high risk to progress to acute myeloid leukemia. Currently, there are no curative FDA-approved medications for myelodysplastic syndromes. Hematopoietic cell transplantation is potentially the only curative option; however, treatment is often unavailable due to age and comorbidities. Hypomethylating agents, azacitidine and decitabine, and the immunomodulatory agent, lenalidomide, are the only FDA approved medications for the treatment of MDS, all of which are noncurative. Venetoclax, an inhibitor of the antiapoptotic protein BCL-2 used to treat chronic lymphocytic leukemia, is currently being evaluated in clinical trials as a monotherapy in high-risk myelodysplastic syndromes/acute myeloid leukemia. We present a patient with transfusion-dependent myelodysplastic syndromes refractory to the current standard of care treatment not a candidate for hematopoietic cell transplantation who responded well to monotherapy treatment with venetoclax and has since remained transfusion-independent.

Opioid-Related Sleep-Disordered Breathing: An Update for Clinicians.

Opioids are an effective treatment for patients with intractable pain. Long-term administration of opioids for pain relief is being delivered by an increasing number of medical providers in the United States including primary care physicians and nonspecialists. One common complication of chronic opioid use is sleep-disordered breathing which can result in various morbidities as well as an increase in all-cause mortality. It is important for providers to understand the relationship between opioids and sleep-disordered breathing as well as methods to improve diagnosis and strategies for treatment. This review aims to update clinicians on the mechanism, diagnosis, and treatment of opioid-related sleep-disordered breathing in order to improve the quality of care for patients with chronic pain.

Pulmonary Haemosiderosis Secondary to Hereditary Haemochromatosis; a Case Report.

Introduction: Hereditary haemochromatosis (HH) is an autosomal recessive disease of increased intestinal absorption of iron, leading to accumulation in tissues which may progress to organ damage, most commonly in the liver. Iron deposition in the liver can lead to cirrhosis and hepatocellular carcinoma. Other common manifestations of haemochromatosis include diabetes, bronzing of the skin, arthropathy and cardiomyopathy. Here, we describe a case of pulmonary haemosiderosis secondary to HH. Case Description: A 49-year-old male with no medical history or family history of iron overload presented with fatigue, shortness of breath and chest pain after a recent finding of elevated ferritin. The patient was found to have biallelic C282Y mutations of the human homeostatic iron regulator protein (HFE) protein and after further workup with laboratory tests and imaging was diagnosed with HH with secondary pulmonary haemosiderosis. The patient is receiving twice weekly phlebotomies and has had an overall improvement in his symptoms. Practical Implications: The presentation of haemochromatosis can vary widely depending on the severity of iron overload and the presence of conditions that predispose organ dysfunction. Pulmonary haemosiderosis is a very rare manifestation of HH. This report illustrates the various manifestations of this disease and provides insight into this rare presentation to improve the diagnosis of this disease.

Investigating the DNA-Binding Site for VirB, a Key Transcriptional Regulator of Shigella Virulence Genes, Using an In Vivo Binding Tool.

The transcriptional anti-silencing and DNA-binding protein, VirB, is essential for the virulence of Shigella species and, yet, sequences required for VirB-DNA binding are poorly understood. While a 7-8 bp VirB-binding site has been proposed, it was derived from studies at a single VirB-dependent promoter, icsB. Our previous in vivo studies at a different VirB-dependent promoter, icsP, found that the proposed VirB-binding site was insufficient for regulation. Instead, the required site was found to be organized as a near-perfect inverted repeat separated by a single nucleotide spacer. Thus, the proposed 7-8 bp VirB-binding site needed to be re-evaluated. Here, we engineer and validate a molecular tool to capture protein-DNA binding interactions in vivo. Our data show that a sequence organized as a near-perfect inverted repeat is required for VirB-DNA binding interactions in vivo at both the icsB and icsP promoters. Furthermore, the previously proposed VirB-binding site and multiple sites found as a result of its description (i.e., sites located at the virB, virF, spa15, and virA promoters) are not sufficient for VirB to bind in vivo using this tool. The implications of these findings are discussed.

Insights into transcriptional silencing and anti-silencing in Shigella flexneri: a detailed molecular analysis of the icsP virulence locus.

Transcriptional silencing and anti-silencing mechanisms modulate bacterial physiology and virulence in many human pathogens. In Shigella species, many virulence plasmid genes are silenced by the histone-like nucleoid structuring protein H-NS and anti-silenced by the virulence gene regulator VirB. Despite the key role that these regulatory proteins play in Shigella virulence, their mechanisms of transcriptional control remain poorly understood. Here, we characterize the regulatory elements and their relative spacing requirements needed for the transcriptional silencing and anti-silencing of icsP, a locus that requires remotely located regulatory elements for both types of transcriptional control. Our findings highlight the flexibility of the regulatory elements' positions with respect to each other, and yet, a molecular roadblock docked between the VirB binding site and the upstream H-NS binding region abolishes transcriptional anti-silencing by VirB, providing insight into transcriptional anti-silencing. Our study also raises the need to re-evaluate the currently proposed VirB binding site. Models of transcriptional silencing and anti-silencing at this genetic locus are presented, and the implications for understanding these regulatory mechanisms in bacteria are discussed.