The Shunt of It.

Pulmonary arteriovenous malformations (PAVMs) are rare and most often identified in patients with hereditary hemorrhagic telangiectasia (HHT). We describe a patient with severe hypoxemia and orthodeoxia with imaging findings consistent with PAVMs. Resected lung pathologic findings confirmed the presence of numerous microscopic vascular abnormalities within the right lower lobe that was consistent with diffuse pulmonary arteriovenous shunts. Family history was negative for HHT but was positive for pulmonary arterial hypertension (PAH) in two second-degree relatives. A vascular malformation gene panel was negative for genes that commonly are associated with HHT but identified a pathogenic variant in the gene encoding bone morphogenetic protein receptor-2 (BMPR2 p.Cys123∗). Pathogenic variants in BMPR2 are a well-known cause of hereditary PAH; there have been several reports to date of patients with PAVMs and PAH. However, this is the first patient to be reported with a pathogenic variant in BMPR2 to have PAVMs in isolation.

Mechanics of lung cancer: A finite element model shows strain amplification during early tumorigenesis.

Early lung cancer lesions develop within a unique microenvironment that undergoes constant cyclic stretch from respiration. While tumor stiffening is an established driver of tumor progression, the contribution of stress and strain to lung cancer is unknown. We developed tissue scale finite element models of lung tissue to test how early lesions alter respiration-induced strain. We found that an early tumor, represented as alveolar filling, amplified the strain experienced in the adjacent alveolar walls. Tumor stiffening further increased the amplitude of the strain in the adjacent alveolar walls and extended the strain amplification deeper into the normal lung. In contrast, the strain experienced in the tumor proper was less than the applied strain, although regions of amplification appeared at the tumor edge. Measurements of the alveolar wall thickness in clinical and mouse model samples of lung adenocarcinoma (LUAD) showed wall thickening adjacent to the tumors, consistent with cellular response to strain. Modeling alveolar wall thickening by encircling the tumor with thickened walls moved the strain amplification radially outward, to the next adjacent alveolus. Simulating iterative thickening in response to amplified strain produced tracks of thickened walls. We observed such tracks in early-stage clinical samples. The tracks were populated with invading tumor cells, suggesting that strain amplification in very early lung lesions could guide pro-invasive remodeling of the tumor microenvironment. The simulation results and tumor measurements suggest that cells at the edge of a lung tumor and in surrounding alveolar walls experience increased strain during respiration that could promote tumor progression.

Macrophage HIF-1α Is an Independent Prognostic Indicator in Kidney Cancer.

PURPOSE: Clear cell renal cell carcinoma (ccRCC) is frequently associated with inactivation of the von Hippel-Lindau tumor suppressor, resulting in activation of HIF-1α and HIF-2α. The current paradigm, established using mechanistic cell-based studies, supports a tumor promoting role for HIF-2α, and a tumor suppressor role for HIF-1α. However, few studies have comprehensively examined the clinical relevance of this paradigm. Furthermore, the hypoxia-associated factor (HAF), which regulates the HIFs, has not been comprehensively evaluated in ccRCC. EXPERIMENTAL DESIGN: To assess the involvement of HAF/HIFs in ccRCC, we analyzed their relationship to tumor grade/stage/outcome using tissue from 380 patients, and validated these associations using tissue from 72 additional patients and a further 57 patients treated with antiangiogenic therapy for associations with response. Further characterization was performed using single-cell mRNA sequencing (scRNA-seq), RNA-in situ hybridization (RNA-ISH), and IHC. RESULTS: HIF-1α was primarily expressed in tumor-associated macrophages (TAMs), whereas HIF-2α and HAF were expressed primarily in tumor cells. TAM-associated HIF-1α was significantly associated with high tumor grade and increased metastasis and was independently associated with decreased overall survival. Furthermore, elevated TAM HIF-1α was significantly associated with resistance to antiangiogenic therapy. In contrast, high HAF or HIF-2α were associated with low grade, decreased metastasis, and increased overall survival. scRNA-seq, RNA-ISH, and Western blotting confirmed the expression of HIF-1α in M2-polarized CD163-expressing TAMs. CONCLUSIONS: These findings highlight a potential role of TAM HIF-1α in ccRCC progression and support the reevaluation of HIF-1α as a therapeutic target and marker of disease progression.

Structural variation and its potential impact on genome instability: Novel discoveries in the EGFR landscape by long-read sequencing.

Structural variation (SV) is typically defined as variation within the human genome that exceeds 50 base pairs (bp). SV may be copy number neutral or it may involve duplications, deletions, and complex rearrangements. Recent studies have shown SV to be associated with many human diseases. However, studies of SV have been challenging due to technological constraints. With the advent of third generation (long-read) sequencing technology, exploration of longer stretches of DNA not easily examined previously has been made possible. In the present study, we utilized third generation (long-read) sequencing techniques to examine SV in the EGFR landscape of four haplotypes derived from two human samples. We analyzed the EGFR gene and its landscape (+/- 500,000 base pairs) using this approach and were able to identify a region of non-coding DNA with over 90% similarity to the most common activating EGFR mutation in non-small cell lung cancer. Based on previously published Alu-element genome instability algorithms, we propose a molecular mechanism to explain how this non-coding region of DNA may be interacting with and impacting the stability of the EGFR gene and potentially generating this cancer-driver gene. By these techniques, we were also able to identify previously hidden structural variation in the four haplotypes and in the human reference genome (hg38). We applied previously published algorithms to compare the relative stabilities of these five different EGFR gene landscape haplotypes to estimate their relative potentials to generate the EGFR exon 19, 15 bp canonical deletion. To our knowledge, the present study is the first to use the differences in genomic architecture between targeted cancer-linked phased haplotypes to estimate their relative potentials to form a common cancer-linked driver mutation.

Cribriform-Morular Variant of Papillary Thyroid Carcinoma With Poorly Differentiated Features: A Case Report With Immunohistochemical and Molecular Genetic Analysis.

Cribriform-morular variant of papillary thyroid carcinoma (CMVPTC) is usually an inherited malignancy and may be a presenting indicator of familial adenomatous polyposis syndrome although it may occasionally be sporadic. Known CMVPTC mutations include adenomatous polyposis coli ( APC) and ß-catenin ( CTNNB1) genes. Despite its malignant classification, CMVPTC is considered to be a well-differentiated thyroid tumor with a generally good behavior. In contrast, poorly differentiated thyroid carcinoma is an aggressive tumor. We report a case of CMVPTC with poorly differentiated features in a young female without phenotypic features of familial adenomatous polyposis but with known germline alterations of the APC gene. High throughput sequencing showed germline chromosome 5q deletion encompassing the APC gene in all components with additional unique genetic alterations in the somatic components. A single nucleotide substitution (c.1548+1G>A, NM_000038.5) located one base pair downstream of exon 12 of the APC gene was identified in the CMVPTC component, and a pathogenic frameshift deletion in exon 14 of APC (c.3642del, p.Ser1214Argfs*51, NM_000038.5) was identified in the poorly differentiated thyroid carcinoma component. No other cancer-associated genes were identified by our techniques. Our case represents a rare phenomenon of poorly differentiated features in association with CMVPTC. To our knowledge, ours is the only such report of poorly differentiated features arising in association with an inherited CMVPTC.

Multifocal cavernous hemangioma of the jugular foramen: a rare skull base vascular malformation.

Jugular foramen cavernous hemangiomas are extremely rare vascular malformations, and, to the best of the authors' knowledge, their occurrence as multifocal lesions involving both intra- and extracranial compartments has never been reported before. Here, the authors describe the case of a 60-year-old woman with a complex multifocal jugular foramen cavernous hemangioma. The patient presented with signs and symptoms concerning for jugular foramen syndrome, as well as a right neck mass. Surgical extirpation of the lesion was achieved by a multidisciplinary team via a right infratemporal fossa approach (Fisch type A) with concurrent high neck dissection and a closure buttressed with an autologous fat graft and a temporoparietal fascial flap. Although rare, cavernous hemangiomas should be included in the differential diagnosis of jugular foramen masses.

Pulmonary Mycobacterial Spindle Cell Pseudotumor: A Report of 3 Cases Including a Practical Approach to Histopathologic Recognition of This Unusual Entity.

Mycobacterial spindle cell pseudotumor (MSP) is a rare benign spindle cell lesion containing acid-fact mycobacteria. These lesions are most commonly identified in the lymph nodes, skin, spleen, or bone marrow of immunocompromised patients and only rarely involve the lungs. We report 3 cases of pulmonary MSP, which include 2 patients who are known to be HIV-positive. The histopathological diagnosis of MSP in the lung lends itself to many challenges due to its rare incidence and its spindled tumor-like appearance. The differential diagnosis is broad and includes both benign and malignant entities. We highlight the importance of the clinical context in which these lesions typically present and the morphologic spectrum of features seen, and we offer a practical approach to the workup of pulmonary mycobacterial pseudotumor. Appropriate recognition of this entity should lead to an accurate diagnosis of a treatable benign condition despite the clinical presentation often favoring malignancy.

An atypical presentation of cardiac tamponade and periorbital swelling in a patient with eosinophilic granulomatosis with polyangiitis: a case report.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis is a rare, necrotizing systemic vasculitis associated with asthma and hypereosinophilia. Its cause and pathophysiology are still being elucidated. CASE PRESENTATION: We report a case of eosinophilic granulomatosis with polyangiitis in a 50-year-old Caucasian woman who presented with chest pain, dyspnea at rest, fever, and periorbital swelling. She was found to have significant hypereosinophilia and cardiac tamponade physiology. A biopsy confirmed extensive infiltration of both lungs and pericardium by eosinophils. She did not have any anti-neutrophil cytoplasmic antibodies. CONCLUSIONS: Eosinophilic granulomatosis with polyangiitis diagnosis does not require the presence of anti-neutrophil cytoplasmic antibodies. Anti-neutrophil cytoplasmic antibody-positive and anti-neutrophil cytoplasmic antibody-negative eosinophilic granulomatosis with polyangiitis may present with different clinical phenotypes, perhaps suggesting two distinct disease etiologies and distinct pathophysiology.

Targeted Intraceptor Nanoparticle for Neovascular Macular Degeneration: Preclinical Dose Optimization and Toxicology Assessment.

Neovascular age-related macular degeneration (AMD) is treated with anti-VEGF intravitreal injections, which can cause geographic atrophy, infection, and retinal fibrosis. To minimize these toxicities, we developed a nanoparticle delivery system for recombinant Flt23k intraceptor plasmid (RGD.Flt23k.NP) to suppress VEGF intracellularly within choroidal neovascular (CNV) lesions in a laser-induced CNV mouse model through intravenous administration. In the current study, we examined the efficacy and safety of RGD.Flt23k.NP in mice. The effect of various doses was determined using fluorescein angiography and optical coherence tomography to evaluate CNV leakage and volume. Efficacy was determined by the rate of inhibition of CNV volume at 2 weeks post-treatment. RGD.Flt23k.NP had peak efficacy at a dose range of 30-60 µg pFlt23k/mouse. Using the lower dose (30 µg pFlt23k/mouse), RGD.Flt23k.NP safety was determined both in single-dose groups and in repeat-dose (three times) groups by measuring body weight, organ weight, hemoglobin levels, complement C3 levels, and histological changes in vital organs. Neither toxicity nor inflammation from RGD.Flt23k.NP was detected. No side effect was detected on visual function. Thus, systemic RGD.Flt23k.NP may be an alternative to standard intravitreal anti-VEGF therapy for the treatment of neovascular AMD.

Pulmonary arterial hypertension in primary amyloidosis.

Amyloidosis involves extravascular deposition of fibrillar proteins within tissues and organs. Primary light chain amyloidosis represents the most common form of systemic amyloidosis involving deposition of monoclonal immunoglobulin light chains. Although pulmonary amyloid deposition is common in primary amyloidosis, clinically significant pulmonary amyloidosis is uncommon, and elevated pulmonary artery pressures are rarely observed in the absence of other underlying etiologies for pulmonary hypertension, such as elevated filling pressures secondary to cardiac amyloid. In this case report, we present a patient with primary light chain amyloidosis and pulmonary arterial hypertension in the setting of pulmonary vascular and right ventricular myocardial amyloid deposition.

Serum osteopontin and tissue inhibitor of metalloproteinase 1 as diagnostic and prognostic biomarkers for pancreatic adenocarcinoma.

OBJECTIVES: Pancreatic ductal adenocarcinoma (PDAC) has a dismal 5-year survival rate of 5%. There is an urgent need for early detection while the tumors are small and surgically resectable. We assessed serum osteopontin (OPN) and tissue inhibitor of metalloproteinase 1 (TIMP-1) as possible diagnostic and prognostic biomarkers in a novel cohort of patients with pancreatic cancer. METHODS: Osteopontin and TIMP-1 levels were determined in sera from 86 patients with PDAC, 86 healthy control subjects, and 48 patients with chronic pancreatitis. Regression models were used to relate OPN and TIMP-1 to sex, age, stage, class, and treatment. Survival analyses were performed using univariate and multivariate Cox models. RESULTS: The serum levels of both OPN and TIMP-1 distinguished PDAC from chronic pancreatitis (P ≤ 0.0001) and healthy control subjects (P < 0.0001). The serum levels of both OPN and TIMP-1 also distinguished early-stage resectable PDAC cases from chronic pancreatitis (P < 0.04) and healthy control subjects (P < 0.01). High serum levels of OPN were significantly correlated with reduced patient survival. CONCLUSIONS: Serum OPN and TIMP-1 have use as diagnostic biomarkers in PDAC. Our data suggest a potential benefit of using OPN, TIMP-1, and CA 19-9 in a panel to improve diagnostic accuracy in PDAC.

Solitary peripheral pulmonary papilloma evaluation on frozen section: a potential pitfall for the pathologist.

Endobronchial papilloma is a rare entity that is in the differential for solitary pulmonary nodule. It almost always follows a benign course, with only rare malignant transformation being reported in the squamous variant. No malignant transformation of the glandular variant has been reported to the best of our knowledge, and therefore endobronchial papilloma must be distinguished from more aggressive neoplasms. This distinction is particularly important when one encounters this neoplasm in a peripheral location at frozen section. We report a case of a 65-year-old female with an incidentally discovered solitary peripheral pulmonary nodule identified during a commercial whole-body screening computed tomography (CT) scan. Interval scans revealed a concerning doubling time, and she presented to the surgical service for removal of the mass. Intraoperative frozen section evaluation revealed histologic characteristics favoring a benign neoplasm. Permanent histologic section revealed a glandular papilloma. Over 7 years of follow-up revealed a benign clinical course.

KIT mutations in ocular melanoma: frequency and anatomic distribution.

KIT mutations are known to occur in ~15% of chronic sun damaged cutaneous, mucosal, and acral melanomas. Melanomas with demonstrated activating mutations in KIT or platelet-derived growth factor receptor A (PDGFRA) may benefit from treatment with tyrosine kinase inhibitors. Currently, the limited data regarding KIT mutational status in ocular melanoma suggest that activating mutations are extremely rare. PDGFRA mutational status in ocular melanoma has not been determined. Seventy-five ocular melanomas (53 choroidal, 6 iris, 11 ciliary body, and 5 conjuctival) were selected from the files of the Department of Ophthalmology. High-resolution melting curve analysis and sequencing were performed to detect mutations in KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18. Results of mutational analysis were correlated with anatomical site and KIT (CD117) immunohistochemistry. Eight of 75 (11%) ocular melanomas contained mutations in either the KIT or PDGFRA gene. Five of 53 (9%) choroidal melanomas were associated with mutations (KIT exon 11=3; KIT exon 17=1; PDGFRA intron 18=1). Two of six (33%) iris melanomas and a single (9%) ciliary body melanoma harbored KIT exon 11 mutations. No mutations were identified in conjunctival melanomas. The distribution of KIT and PDGFRA mutations by ocular melanoma anatomical site did not reach statistical significance (P=0.393) CD117 positivity was not predictive of KIT mutational status as only 6 of 58 (10%) CD177-positive tumors harbored KIT mutations. In addition, a KIT exon 17 mutation was identified in one CD117-negative tumor. KIT and PDGFRA mutations do occur in ocular melanomas at a frequency (11%) that is similar to acral and mucosal melanomas. Limited correlation of CD117 positivity with mutational status suggests that all ocular melanomas should undergo mutational analysis to determine if imatinib therapy is appropriate.

Serum platelet factor 4 is an independent predictor of survival and venous thromboembolism in patients with pancreatic adenocarcinoma.

BACKGROUND: Improved diagnostic, predictive, and prognostic biomarkers for pancreatic ductal adenocarcinoma (PDAC) are urgently needed. Platelet factor 4 (PF4) has been proposed as a diagnostic biomarker for PDAC. We assessed the diagnostic and prognostic potential of serum PF4 levels in PDAC patients. METHODS: Serum PF4 levels were determined by enzyme-linked immunosorbent assay in an initial cohort of 62 PDAC patients, 62 healthy control subjects, and 34 chronic pancreatitis patients. A second validation set consisted of 71 PDAC patients. Linear regression models were used to relate PF4 to class, gender, age, stage, platelet count, and diagnosis. Survival analyses were done using univariate and multivariate Cox models. RESULTS: In the initial cohort, serum PF4 levels distinguished PDAC from chronic pancreatitis patients (P = 0.011), but not from healthy control subjects (P = 0.624). In PDAC patients, high serum PF4 level significantly predicted decreased survival independent of all covariates examined (P < 0.01). The prognostic relationship of serum PF4 levels remained significant in the validation set. Venous thromboembolism (VTE) occurred in 20% of the 133 PDAC patients. The VTE risk was higher in subjects with elevated PF4 levels (P = 0.009). CONCLUSIONS: Serum PF4 is shown for the first time to be prognostic for survival in PDAC patients. High PF4 is associated with an increased risk for the development of VTE. IMPACT: Serum PF4 levels may be useful for patient stratification and for directing treatment options in patients with pancreatic cancer including anticoagulation prophylaxis. The relationship between high PF4 levels and poorer outcomes requires further study.

Comparison of esomeprazole to aerosolized, swallowed fluticasone for eosinophilic esophagitis.

BACKGROUND: Both gastroesophageal reflux disease and allergy/atopy have been implicated in the pathogenesis of eosinophilic esophagitis (EoE). There are no prospective studies comparing treatment of EoE with acid suppression versus topical corticosteroids. OBJECTIVE: To determine the outcome of adult eosinophilic esophagitis patients treated with esomeprazole versus topical fluticasone. DESIGN: Prospective randomized controlled trial. SETTING: Academic medical center. PARTICIPANTS: Adults (18-80) diagnosed with EoE by symptoms of dysphagia and esophageal biopsies with >or=15 eosinophils/hpf. INTERVENTIONS: Subjects were randomized to esomeprazole (40 mg by mouth every morning) or aerosolized, swallowed fluticasone (440 mcg by mouth twice a day) for 8 weeks. MAIN OUTCOME MEASUREMENTS: Improvement in dysphagia (8-point scale), esophageal eosinophil infiltration before and after treatment, prevalence of GERD measured by validated questionnaire and baseline pH study. RESULTS: About 56% (14/25) had acid reflux by pH study. There was no difference between treatment groups in improvement in dysphagia scores [3/12 (25%) of the esomeprazole group versus 6/12 (50%) in the fluticasone group, P = 0.40]. Eosinophil infiltration decreased with treatment in both groups, and there was no difference in the amount of decrease between groups (P = 0.70). LIMITATIONS: Small sample size, unexpectedly high drop-out rate. CONCLUSIONS: Gastroesophageal reflux disease is common in adult eosinophilic esophagitis patients. Dysphagia improves and esophageal eosinophilic infiltration decreases with either treatment. There was no difference in degree of improvement in dysphagia or eosinophil infiltration in patients treated with either topical fluticasone or oral esomeprazole. GERD may be important in the pathogenesis of adult EoE.

Notch and Kras reprogram pancreatic acinar cells to ductal intraepithelial neoplasia.

Efforts to model pancreatic cancer in mice have focused on mimicking genetic changes found in the human disease, particularly the activating KRAS mutations that occur in pancreatic tumors and their putative precursors, pancreatic intraepithelial neoplasia (PanIN). Although activated mouse Kras mutations induce PanIN lesions similar to those of human, only a small minority of cells that express mutant Kras go on to form PanINs. The basis for this selective response is unknown, and it is similarly unknown what cell types in the mature pancreas actually contribute to PanINs. One clue comes from the fact that PanINs, unlike most cells in the adult pancreas, exhibit active Notch signaling. We hypothesize that Notch, which inhibits differentiation in the embryonic pancreas, contributes to PanIN formation by abrogating the normal differentiation program of tumor-initiating cells. Through conditional expression in the mouse pancreas, we find dramatic synergy between activated Notch and Kras in inducing PanIN formation. Furthermore, we find that Kras activation in mature acinar cells induces PanIN lesions identical to those seen upon ubiquitous Kras activation, and that Notch promotes both initiation and dysplastic progression of these acinar-derived PanINs, albeit short of invasive adenocarcinoma. At the cellular level, Notch/Kras coactivation promotes rapid reprogramming of acinar cells to a duct-like phenotype, providing an explanation for how a characteristically ductal tumor can arise from nonductal acinar cells.

Collecting duct carcinoma arising in association with BK nephropathy post-transplantation in a pediatric patient. A case report with immunohistochemical and in situ hybridization study.

The development of malignancy in a renal transplant graft is an uncommon phenomenon. A renal neoplasm developing in the adult donor kidney of a pediatric transplant recipient has only rarely been reported. We report a case of collecting duct carcinoma arising in association with BK virus nephropathy in an adult living-related donor renal allograft to a pediatric recipient. Our case is the second report of neoplasia occurring in association with BK virus nephropathy post-transplantation, suggesting that BK virus may play a role in oncogenesis. It has been proposed that the T-Ag protein encoded by the polyomavirus family of viruses disrupts chromosomal integrity, creating oncogenes, and inactivating tumor suppressor genes. In our study, immunohistochemical staining with antibody directed against BK virus large T antigen showed nuclear staining within urothelium, tubular epithelium, tubular intraepithelial neoplasia, and invasive carcinoma. In situ hybridization did not identify BK virus DNA within neoplastic cells. T-Ag protein expression has been shown to be tumor-specific in bladder, gastric, and colorectal cancers. The finding of T-Ag protein expression in both intraepithelial and invasive neoplastic tissues in our case raises the possibility of BK virus as a causative agent in oncogenesis.

Anti-inflammatory effects of PPAR-gamma agonists directly correlate with PPAR-gamma expression during acute pancreatitis.

Peroxisome proliferator-activated receptors (PPARs) are ligand-inducible transcription factors that regulate cellular energy and lipid metabolism. PPAR-gamma agonists also have potent anti-inflammatory properties through down-regulation of early inflammatory response genes. The role of PPAR-gamma in acute pancreatitis has not been adequately examined. In this study, we determined the effect of PPAR-gamma agonists on the severity of pancreatitis and sought to correlate PPAR-gamma expression in pancreatic acinar cells and the severity of acute pancreatitis in vivo. Acute pancreatitis was induced in mice by hyperstimulation with the cholecystokinin analog, cerulein. PPAR-gamma agonists were administered by intraperitoneal injection 15-30 minutes before induction of pancreatitis (pretreatment) or at various times after induction of pancreatitis (treatment). Pancreata and serum were harvested over the course of 24 hours. Serum amylase activity and glucose levels were measured. Pancreata were used for histological evaluation as well as protein and mRNA analysis. Pretreatment of mice with the PPAR-gamma agonists 15-deoxy-Delta12, 14-prostaglandin J(2), or troglitazone significantly reduced the severity of pancreatitis in a dose-dependent manner. This reduction was indicated by reduced serum amylase activity and histological damage (leukocyte infiltration, vacuolization, and necrosis). Although cerulein decreased PPAR-gamma expression in the pancreas, pretreatment with agonists maintained PPAR-gamma expression early in acute pancreatitis. The expression of PPAR-gamma inversely correlated with pancreatitis severity and expression of the proinflammatory cytokines, interleukin-6, and tumor necrosis factor-alpha. Treatment with troglitazone after the induction of pancreatitis reduced serum amylase activity. The results suggest that PPAR-gamma plays a direct role in the inflammatory cascade during the early events of acute pancreatitis. Our data are the first to demonstrate that PPAR-gamma agonists represent a promising therapeutic strategy for acute pancreatitis.