Genomic diversity of Salmonella enterica isolated from raw chicken at retail establishments in Mexico.

The genomic diversity of circulating non-typhoidal Salmonella in raw chicken was investigated in three states of central Mexico. A total of 192 S. enterica strains from chicken meat samples collected at supermarkets, fresh markets, and butcher shops were analyzed by whole-genome sequencing. The serovar distribution, occurrence of genes encoding for antimicrobial resistance, metal resistance, biocide resistance, plasmids and virulence factors, and clonal relatedness based on single nucleotide polymorphism (SNP) analysis were investigated. Serovars Infantis, Schwarzengrund and Enteritidis predominated among twenty identified. The distribution of serovars and proportion of AMR genes was different according to the state, year, season, and retail establishment (p < 0.001). Genes encoding metals resistance were identified in all the strains. A total of 145 virulence genes were identified and strains were classified into 32 virulotypes; serovars Infantis, Typhimurium, and Enteritidis showed the highest number of virulence genes. The strains matched 34 SNP clusters in the NCBI Pathogen Detection server and 59 %, which corresponded to Infantis, Schwarzengrund, Saintpaul, and Enteritidis, were associated with five major clusters and matched with chicken, environmental and clinical isolates from at least three countries. These results provide useful information to understand the epidemiology of Salmonella, conduct microbial risk assessment, and design risk-based control measures.

The Role of Medication, Mental Illness, and Social Isolation on the Development of the Fetus in the Context of the COVID-19 Pandemic.

As we enter the COVID-19 post-pandemic period, uncertainty surrounds the impact of the varied effects of medications, mental illness, and social isolation on children born during the pandemic. Medications like selective serotonin reuptake inhibitors (SSRIs) and benzodiazepines during pregnancy, coupled with pandemic-induced social isolation, may contribute to anxiety, depression, and behavioral issues in the offspring. Supporting evidence shows SSRIs' influence on brain development, while third-trimester benzodiazepine use may lead to neonatal withdrawal syndrome. Social isolation during the pandemic has also been linked to increased maternal depression and anxiety. This editorial emphasizes the need for increased surveillance in educational settings and early behavioral assessments by pediatricians. Further research is required to understand the long-term effects of maternal SSRIs. This knowledge can aid in timely interventions to protect the well-being of children born during COVID-19.

Genomic analysis of the MLST population structure and antimicrobial resistance genes associated with Salmonella enterica in Mexico.

Salmonella enterica is one of the most commonly reported foodborne pathogens by public health agencies worldwide. In this study, the multilocus sequence typing (MLST) population structure and frequency of antimicrobial resistance (AMR) genes were evaluated in S. enterica strains from Mexico (n = 2561). The most common sources of isolation were food (44.28%), environment (27.41%), animal-related (24.83%), and human (3.48%). The most prevalent serovars were Newport (8.51%), Oranienburg (7.03%), Anatum (5.78%), Typhimurium (5.12%), and Infantis (4.57%). As determined by the 7-gene MLST scheme, the most frequent sequence types were ST23, ST64, and ST32. The core genome MLST scheme identified 132 HC2000 and 195 HC900 hierarchical clusters, with the HC2000_2 cluster being the most prevalent in Mexico (n = 256). A total of 78 different AMR genes belonging to 13 antimicrobial classes were detected in 638 genomic assemblies of S. enterica. The most frequent class was aminoglycosides (31.76%), followed by tetracyclines (12.53%) and sulfonamides (11.91%). These results can help public health agencies in Mexico prioritize their efforts and resources to increase the genomic sequencing of circulating Salmonella strains. Additionally, they provide valuable information for local and global public health efforts to reduce the impact of foodborne diseases and AMR.

COVID-19 and Placental Infection: Are Fetal Survivors at Risk of Long-Term Cardiovascular Complications?

As we enter the fourth year of the coronavirus disease 2019 (COVID-19) pandemic, it has become obvious that adult survivors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are susceptible to numerous complications in various organ systems. SARS-CoV-2 placental infection is an unanticipated complication of COVID-19 during pregnancy. We hypothesize that fetal survivors of SARS-CoV-2 placentitis are susceptible to long-term cardiovascular complications.

Postinfantile Giant Cell Hepatitis Secondary to Rheumatoid Arthritis.

Postinfantile giant cell hepatitis (PIGCH), also known as syncytial giant cell hepatitis, continues to be a poorly defined and rare disease presentation in the adult population. Although a common finding in neonates, there is limited literature on the disease process, causes, and treatment success of PIGCH in adults. A strong association between autoimmune disorders and PIGCH, considerably so in the case of autoimmune hepatitis, has been established. However, there have been limited to no reports of PIGCH secondary to rheumatoid arthritis. Our clinical case aims to bring forth a vignette of PIGCH to spotlight this ill-defined disease in the adult population and highlight some of the proposed causes, treatments, and laboratory markers.

Risk ranking of food categories associated with Salmonella enterica contamination in the central region of Mexico.

To prevent and control foodborne diseases, there is a fundamental need to identify the foods that are most likely to cause illness. The goal of this study was to rank 25 commonly consumed food products associated with Salmonella enterica contamination in the Central Region of Mexico. A multicriteria decision analysis (MCDA) framework was developed to obtain an S. enterica risk score for each food product based on four criteria: probability of exposure to S. enterica through domestic food consumption (Se); S. enterica growth potential during home storage (Sg); per capita consumption (Pcc); and food attribution of S. enterica outbreak (So). Risk scores were calculated by the equation Se*W1 +Sg*W2 +Pcc*W3 +So*W4 , where each criterion was assigned a normalized value (1-5) and the relative weights (W) were defined by 22 experts' opinion. Se had the largest effect on the risk score being the criterion with the highest weight (35%; IC95% 20%-60%), followed by So (24%; 5%-50%), Sg (23%; 10%-40%), and Pcc (18%; 10%-35%). The results identified chicken (4.4 ± 0.6), pork (4.2 ± 0.6), and beef (4.2 ± 0.5) as the highest risk foods, followed by seed fruits (3.6 ± 0.5), tropical fruits (3.4 ± 0.4), and dried fruits and nuts (3.4 ± 0.5), while the food products with the lowest risk were yogurt (2.1 ± 0.3), chorizo (2.1 ± 0.4), and cream (2.0 ± 0.3). Approaches with expert-based weighting and equal weighting showed good correlation (R2  = 0.96) and did not show significant differences among the ranking order in the top 20 tier. This study can help risk managers select interventions and develop targeted surveillance programs against S. enterica in high-risk food products.

Genotypic and phenotypic quantitative microbial risk assessment model of human salmonellosis related to the consumption of chicken meat in the central region of Mexico.

Chicken meat is often associated withSalmonella entericacontamination worldwide. This study proposes a risk assessment model for human salmonellosis linked to the domestic consumption of chicken meat in the central region of Mexico, incorporating genotypic and phenotypic data. SixS. entericagroups were used, considering the presence of specific virulence genes and multidrug resistance (MDR). Sixteen exposure scenarios were established considering retail point (RP1 = fresh market/butcher shop; RP2 = mini-super/supermarket), transportation, home storage, cooking, and cross-contamination. The model predicted a mean annual salmonellosis cases of 66,754 due to chicken consumption (CI95% 10775-231606). The mean probability of illness (Pill) among the exposure scenarios ranged from 2.5 × 10-9 to 3.7 × 10-6, 7.7 × 10-8 to 1.1 × 10-4, and 6.7 × 10-4 to 7.8 × 10-2 for low, moderate, and high virulence groups. Exposure scenarios with the highest Pill were not responsible for most cases due to their low frequency of occurrence. The high virulence/ MDR group was responsible for most cases (66.5 %), despite the low S. enterica prevalence (RP1 0.5 % and RP2 5.0 %). The years lost due to disability (YLD) value for MDR was 2.6 × higher than for non-MDR. Spearman rank showed that the inputs with higher influence on the variability of salmonellosis depended on the type of exposure scenario. For example, the cooking temperature and time had the most significant influence in the scenarios where S. enterica can survive after cooking. Including the microbial genotypic and phenotypic characteristics in risk assessment modeling highlights the importance of focusing on high-virulent and MDR strains, which are not the most frequent but represent the highest public health risk.

Comparative Study between Two Simple Synthesis Methods for Obtaining Green Gold Nanoparticles Decorating Silica Particles with Antibacterial Activity.

The SiO2 particles system is one of the most common ways to protect colloidal metal systems, such as gold nanoparticles, from aggregation and activity loss due to their high chemical stability and low reactivity. In this study, silica green gold nanoparticles (AuNPs synthesized with mullein extract) were fabricated using two different sol-gel methods. The nanoparticles were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Transformed Infrared (FTIR), and the antibacterial activity against pathogens (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica). Synthesis-1 nanoparticles had a kidney-shaped form and uniform distribution, while synthesis-2 nanoparticles had a spherical and non-uniform form. Characterization showed that temperature is an important factor in the distribution of AuNPs in silica; a decrease allowed the formation of Janus-type, and an increase showed a higher concentration of gold in energy-dispersive spectroscopy (EDS) analysis. Overall, similar bands of the two synthesis silica nanoparticles were observed in FTIR, while XRD spectra showed differences in the preferential growth in AuNPs depending on the synthesis. Higher antibacterial activity was observed against S. aureus, which was followed by L. monocytogenes. No differences were observed in the antibacterial activity between the two different sol-gel methods.

Homozygous UNC13A Variant in an Infant With Congenital Encephalopathy and Severe Neuromuscular Phenotype: A Case Report With Detailed Central Nervous System Neuropathologic Findings.

Uncoordinated 13 (UNC13A) affects movement in Caenorhabditis elegans (C. elegans). It is responsible for docking, priming, and stabilizing synaptic vesicle fusion complexes in the neuronal synapse and neuromuscular junction (NMJ). It also plays an important role in central nervous system development. We report the detailed clinical history and central nervous system neuropathologic findings in an infantile case with homozygous UNC13A loss of function variant, in order to advance the understanding of this critically important synaptic vesicle protein. This is the first detailed central nervous system neuropathologic report of this rare case of homozygous UNC13A loss.

Placental Tissue Destruction and Insufficiency From COVID-19 Causes Stillbirth and Neonatal Death From Hypoxic-Ischemic Injury.

CONTEXT.­: Perinatal death is an increasingly important problem as the coronavirus disease 2019 (COVID-19) pandemic continues, but the mechanism of death has been unclear. OBJECTIVE.­: To evaluate the role of the placenta in causing stillbirth and neonatal death following maternal infection with COVID-19 and confirmed placental positivity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). DESIGN.­: Case-based retrospective clinicopathologic analysis by a multinational group of 44 perinatal specialists from 12 countries of placental and autopsy pathology findings from 64 stillborns and 4 neonatal deaths having placentas testing positive for SARS-CoV-2 following delivery to mothers with COVID-19. RESULTS.­: Of the 3 findings constituting SARS-CoV-2 placentitis, all 68 placentas had increased fibrin deposition and villous trophoblast necrosis and 66 had chronic histiocytic intervillositis. Sixty-three placentas had massive perivillous fibrin deposition. Severe destructive placental disease from SARS-CoV-2 placentitis averaged 77.7% tissue involvement. Other findings included multiple intervillous thrombi (37%; 25 of 68) and chronic villitis (32%; 22 of 68). The majority (19; 63%) of the 30 autopsies revealed no significant fetal abnormalities except for intrauterine hypoxia and asphyxia. Among all 68 cases, SARS-CoV-2 was detected from a body specimen in 16 of 28 cases tested, most frequently from nasopharyngeal swabs. Four autopsied stillborns had SARS-CoV-2 identified in internal organs. CONCLUSIONS.­: The pathology abnormalities composing SARS-CoV-2 placentitis cause widespread and severe placental destruction resulting in placental malperfusion and insufficiency. In these cases, intrauterine and perinatal death likely results directly from placental insufficiency and fetal hypoxic-ischemic injury. There was no evidence that SARS-CoV-2 involvement of the fetus had a role in causing these deaths.

Intracranial mesenchymal tumors with FET-CREB fusion are composed of at least two epigenetic subgroups distinct from meningioma and extracranial sarcomas.

'Intracranial mesenchymal tumor, FET-CREB fusion-positive' occurs primarily in children and young adults and has previously been termed intracranial angiomatoid fibrous histiocytoma (AFH) or intracranial myxoid mesenchymal tumor (IMMT). Here we performed genome-wide DNA methylation array profiling of 20 primary intracranial mesenchymal tumors with FET-CREB fusion to further study their ontology. These tumors resolved into two distinct epigenetic subgroups that were both divergent from all other analyzed intracranial neoplasms and soft tissue sarcomas, including meningioma, clear cell sarcoma of soft tissue (CCS), and AFH of extracranial soft tissue. The first subgroup (Group A, 16 tumors) clustered nearest to but independent of solitary fibrous tumor and AFH of extracranial soft tissue, whereas the second epigenetic subgroup (Group B, 4 tumors) clustered nearest to but independent of CCS and also lacked expression of melanocytic markers (HMB45, Melan A, or MITF) characteristic of CCS. Group A tumors most often occurred in adolescence or early adulthood, arose throughout the neuroaxis, and contained mostly EWSR1-ATF1 and EWSR1-CREB1 fusions. Group B tumors arose most often in early childhood, were located along the cerebral convexities or spinal cord, and demonstrated an enrichment for tumors with CREM as the fusion partner (either EWSR1-CREM or FUS-CREM). Group A tumors more often demonstrated stellate/spindle cell morphology and hemangioma-like vasculature, whereas Group B tumors more often demonstrated round cell or epithelioid/rhabdoid morphology without hemangioma-like vasculature, although robust comparison of these clinical and histologic features requires future study. Patients with Group B tumors had inferior progression-free survival relative to Group A tumors (median 4.5 vs. 49 months, p = 0.001). Together, these findings confirm that intracranial AFH-like neoplasms and IMMT represent histologic variants of a single tumor type ('intracranial mesenchymal tumor, FET-CREB fusion-positive') that is distinct from meningioma and extracranial sarcomas. Additionally, epigenomic evaluation may provide important prognostic subtyping for this unique tumor entity.

Detection, quantification, and characterization of Salmonella enterica in mango, tomato, and raw chicken purchased in the central region of Mexico.

To estimate human exposure to Salmonella enterica, it is essential to understand the pathogen distribution and characteristics. Prevalence and concentration of S. enterica were determined in mango, tomato, and raw chicken samples purchased in three states (Aguascalientes, Querétaro, and Guadalajara) located in the central region of Mexico during two seasons. In addition, S. enterica isolates were characterized by absence/presence of 13 virulence genes (chromosomal, prophage, and plasmid) and resistance to 14 antibiotics. A total of 300 samples of mango, 272 of tomato, and 354 of raw chicken were analyzed. The mean of the prevalence (24.9%) and concentration (-0.61 Log MPN/g) of S. enterica in chicken was higher than in mango (1.3%, -1.7 Log MPN/g) and tomato (1.1%, -1.7 Log MPN). Among S. enterica isolates (284), there were 7 different virulotypes, belonging 68.7% of isolates to V2; there was high variability in the presence of mobile genetic elements. The occurrence of specific mobile elements ranged from 81.4% to 11.3% among isolates. Among the isolates, 91.5% were resistant to at least one antibiotic with ampicillin being the most frequent; 54.9% of isolates were multidrug resistant. Data from this study can be used for quantitative microbial risk assessment of S. enterica related to mango, tomato, and raw chicken consumption in the central region of Mexico. PRACTICAL APPLICATION: Data on the prevalence and concentration of Salmonella enterica obtained in this study can be used to estimate the exposure assessment for the consumption of mango, tomato, and chicken in the central region of Mexico. In addition, the characteristics of the S. enterica isolates could be used to select representative strains for future studies to evaluate the intraspecies variability.

N-Glycanase 1 Deficiency Is a Rare Cause of Pediatric Neurodegeneration With Neuronal Inclusions and Liver Steatosis.

Pediatric neurodegeneration is extremely rare and devastating to the families involved. We describe a rare case of pediatric neurodegeneration in a child with N-glycanase 1 (NGLY1) deficiency. This child had an autosomal recessive mutation in NGLY1, the gene coding for the enzyme NGLY1 that was found with exome sequencing. NGLY1 catalyzes protein deglycosylation by cleaving the -aspartyl glycosylamine bond of N-linked glycoproteins and is thereby a component of the endoplasmic reticulum-associated degradation pathway. This child passed away at five years of age after a prolonged clinical course with myoclonic epilepsy, choreoathetosis-like movements, lacrimal duct problems, and severe developmental delay. This autopsy case report shows images of the neuronal inclusions and liver steatosis found in this patient with NGLY1 deficiency and offers a detailed clinical history.

SARS-CoV-2 Placental Infection in an Unvaccinated Mother Resulting in Fetal Demise.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnancy may have devastating complications including fetal demise. Here, we describe a case of SARS-CoV-2 infection in a second-trimester pregnancy. The placenta demonstrated the presence of SARS-CoV-2 viral RNA along with intervillositis and perivillous fibrin deposition. SARS-CoV-2 directly infects the trophoblastic cells of the placenta through the angiotensin-converting enzyme 2 receptor. This case report details the clinical history of a SARS-CoV-2-infected pregnancy with fetal demise. In addition, we show the images of the placental pathology and SARS-CoV-2 RNA in situ studies.

Intracranial mesenchymal tumor with FET-CREB fusion-A unifying diagnosis for the spectrum of intracranial myxoid mesenchymal tumors and angiomatoid fibrous histiocytoma-like neoplasms.

Intracranial mesenchymal tumors with FET-CREB fusions are a recently described group of neoplasms in children and young adults characterized by fusion of a FET family gene (usually EWSR1, but rarely FUS) to a CREB family transcription factor (ATF1, CREB1, or CREM), and have been variously termed intracranial angiomatoid fibrous histiocytoma or intracranial myxoid mesenchymal tumor. The clinical outcomes, histologic features, and genomic landscape are not well defined. Here, we studied 20 patients with intracranial mesenchymal tumors proven to harbor FET-CREB fusion by next-generation sequencing (NGS). The 16 female and four male patients had a median age of 14 years (range 4-70). Tumors were uniformly extra-axial or intraventricular and located at the cerebral convexities (n = 7), falx (2), lateral ventricles (4), tentorium (2), cerebellopontine angle (4), and spinal cord (1). NGS demonstrated that eight tumors harbored EWSR1-ATF1 fusion, seven had EWSR1-CREB1, four had EWSR1-CREM, and one had FUS-CREM. Tumors were uniformly well circumscribed and typically contrast enhancing with solid and cystic growth. Tumors with EWSR1-CREB1 fusions more often featured stellate/spindle cell morphology, mucin-rich stroma, and hemangioma-like vasculature compared to tumors with EWSR1-ATF1 fusions that most often featured sheets of epithelioid cells with mucin-poor collagenous stroma. These tumors demonstrated polyphenotypic immunoprofiles with frequent positivity for desmin, EMA, CD99, MUC4, and synaptophysin, but absence of SSTR2A, myogenin, and HMB45 expression. There was a propensity for local recurrence with a median progression-free survival of 12 months and a median overall survival of greater than 60 months, with three patients succumbing to disease (all with EWSR1-ATF1 fusions). In combination with prior case series, this study provides further insight into intracranial mesenchymal tumors with FET-CREB fusion, which represent a distinct group of CNS tumors encompassing both intracranial myxoid mesenchymal tumor and angiomatoid fibrous histiocytoma-like neoplasms.

Salmonella enterica in Mexico 2000-2017: Epidemiology, Antimicrobial Resistance, and Prevalence in Food.

In Mexico, information of Salmonella enterica cases linked to food consumption is scarce. The objective of this article was to assess how S. enterica affect public health in Mexico. To conduct this study, data on the epidemiology of nontyphoidal S. enterica (NTS), Salmonella Typhi, and Salmonella Paratyphi A collected from 2000 to 2017 through the National Epidemiological Surveillance System of Mexico (Sistema Nacional de Vigilancia Epidemiológica de Mexico [SINAVE]) were used. Geographical distribution, season, age groups, and gender were variables considered to analyze S. enterica incidence. An estimation of cases caused by S. enterica in Mexico was calculated while considering data underestimation and the proportion of foodborne diseases. Information of the prevalence of the pathogen in food and the antimicrobial resistance of isolates from food and human cases were obtained from published studies. Outbreaks of S. enterica derived from imported Mexican products in the Unites States are discussed. In 2017, the numbers of reported cases of NTS (92,013) were two and seven times higher than the reported cases of Salmonella Typhi (45,280) and Salmonella Paratyphi A (12, 458). The NTS incidence was higher in lower socioeconomic Mexican regions. The gaps in the surveillance system make it impossible to establish a reliable tendency among age groups, geographical distribution, and gender. In 2017, the estimated frequency of NTS foodborne cases was 49 times higher than that reported in SINAVE, whereas for Salmonella Typhi and Salmonella Paratyphi A it was 23 times. Fresh meat showed the highest prevalence of S. enterica, and most of their isolates had multidrug resistance. Salmonella Typhimurium was the most common serotype isolated from human cases and food. Food safety agencies in Mexico need to prioritize efforts and resources to establish guidelines to ensure the absence of S. enterica in food.

Food Consumer Behavior and Salmonella Exposure Self-Perception in the Central Region of Mexico.

In Mexico, there is limited information regarding food consumer behaviors at home. The knowledge of food consumption and food handling practices can help to determine more realistically the exposure to different hazards, such as Salmonella spp. on the population. The main goal of this study was to characterize the food consumption habits of five food groups (fruits and vegetables, fresh meat, dairy products, processed meat products, and seafood), food handling practices, and Salmonella exposure self-perception of the population of the central region of Mexico using an online survey. A total of 1,199 surveys were analyzed. The group of fruits and vegetables is the most consumed and one of the most related to the consumer self-perception of suffering from salmonellosis. Mexican consumers regularly use refrigeration as the principal food storage method for the five food groups (42.2% to 90.8%), and generally, they store the products between 2 and 3 days (26.5% to 38.1%). A total of 86.4% of consumers reported that they always wash their hands prior to food preparation. A total of 16.9% and 13.0% use the same cutting board and knife, respectively, to cut more than one product without applying sanitization. Men, people between 20 and 24 years, and people between 60 and 64 years, had the highest risk food handling practices at home. Finally, age (P < 0.0001), education level (P = 0.0004), and suffering from gastrointestinal diseases (P = 0.0005) showed significant effects with self-perception of having salmonellosis. PRACTICAL APPLICATION: Data presented in this study could be used in future risk and exposure assessment research to evaluate the public health risk from the consumption of contaminated food. In addition, it could be used by government agencies to design education campaigns in food safety area.

Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas.

Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.

Ciliated columnar epithelium in the esophagus and gastroesophageal junction: A different perspective from study of a North American population.

An index case of ciliated columnar epithelium in a gastroesophageal (GE) junction biopsy identified in routine surgical pathology practice struck us as highly unusual. However, pathology literature, mainly from Asian populations, reports ciliated columnar epithelium in up to 40% of tissue samples from the upper GI tract. This was inconsistent with our pathology practice experience, so we initiated a local review of cases at our Canadian centre. 1048 consecutive tissue samples from the esophagus and GE junction were reviewed retrospectively and no ciliated epithelium was identified. This review included 1000× oil immersion microscopy of 22 cases with "multilayered epithelium". In 971 cases verified in prospective surgical pathology practice following identification of the index case, 3 additional cases of ciliated columnar epithelium were identified. The index case had ciliated pseudostratified columnar epithelium, resembling respiratory epithelium, and had strong, diffuse expression of TTF-1 by immunohistochemistry. In the other 3 cases, the cilia were located on the surface of a pseudostratified columnar epithelium, a multilayered epithelium, or a low columnar epithelium, all TTF-1 negative. Over a year later, the index case proved to have arisen from a bronchial-esophageal fistula. The other cases were not associated with a fistula. Our conclusion is that ciliated columnar epithelium is rare in Canadian adults (<0.5% of patients). Ciliated epithelium due to a bronchial-esophageal fistula is exceptional, but something to consider if there is a suspicious clinical picture and TTF-1 expression. Other cases might represent a rare metaplastic phenomenon or remnant from fetal development.