Positivo a opiáceos en análisis de drogas de abuso en orina tras consumo de semillas de amapola. A propósito de un caso / Positive for opiates in urine drug of abuse test after poppy seed consumption. A case report

Antecedentes y objetivos: las semillas de amapola, cuyo consumo solas o contenidas en ciertos alimentos es considerado seguro en España desde el punto de vista toxicológico, presentan cierta cantidad de alcaloides opiáceos que pueden originar resultados «falsos positivos» en los análisis de drogas de abuso en muestras de orina, como los realizados de forma rutinaria, entre otros colectivos, al personal de las Fuerzas Armadas. A raíz de un caso detectado en el Instituto de Toxicología de la Defensa de resultado positivo a opiáceos en una persona que reportó el consumo de un pan con semillas de amapola, se propuso realizar un estudio de esta problemática y cómo abordarla desde el punto de vista analítico. Material y método: se estudió en dos voluntarios cómo afectó el consumo de dicho pan, analizándose muestras de orina, tanto por métodos de cribado como de confirmación, y se apoyó en una revisión bibliográfica empleando distintas bases de datos especializadas en referencia a la interferencia del consumo de semillas de amapola con las analíticas de drogas de abuso en muestras de orina. Resultados: aplicando el punto de corte de 300 ng/ml recomendado por la European Workplace Drug Testing Society (EWDTS) resultaron presuntamente positivos a opiáceos el 62,5% de los análisis de cribado. En ciertas muestras, el análisis de confirmación identificó codeína por encima del límite de detección establecido en la técnica analítica. La bibliografía apoyó estos resultados. Conclusiones: para abordar analíticamente esta problemática se ha propuesto incrementar, en la técnica analítica de confirmación, el punto de corte de confirmación y, asimismo, como otras posibles medidas a implementar se ha planteado la detección de tebaína como biomarcador específico del consumo de semillas de amapola y/o el incremento del punto de corte hasta los 2000 ng/ml. (AU)

Antecedents and objectives: Poppy seeds, whose consumption alone or contained in certain foods is considered safe in Spain from the toxicological point of view, have different amounts of opioid alkaloids that can cause «false positive» results in the analysis of drugs of abuse in urine samples, such as those routinely performed, among other groups, on Armed Forces personnel. Following a case detected at the Institute of Toxicology of the Defense of a positive result to opiates in a person who reported the consumption of a bread containing poppy seeds, it was proposed to carry out a study of this problem and how to approach it from the analytical point of view. Material and methods: We studied how the consumption of this bread affected to two volunteers, analyzing urine samples by both screening and confirmation methods, and was supported by a literature review using different specialized databases in reference to the interference of the consumption of poppy seeds and products containing them with the analysis of drugs of abuse in urine samples. Results: Using the 300 ng/ml cut-off point, 62% of the screening tests were presumably positive to opiates. In certain samples the confirmatory analysis identified codeine above the established detection limit. The literature supported these results. Conclusions: In order to deal with this problem analytically, it has been proposed to increase the confirmation cut-off level in the analytical confirmatory technique. In addition, the detection of thebaine as a specific biomarker for poppy seed consumption and/or the increase of the cut-off point to 2000 ng/ml has been proposed as other possible measures to be implemented. (AU)

Risco de resultado falso positivo no rastreamento mamográfico do Brasil / Risk of false-positive result in mammography screening in Brazil / Riesgo de resultados falsos positivos en el cribado mamográfico en Brasil

Resultados falsos positivos na mamografia de rastreamento são comuns a essa intervenção e trazem ônus para as mulheres e o sistema de saúde. O objetivo deste estudo foi estimar o risco de resultado falso positivo no rastreamento mamográfico brasileiro com base em dados de sistemas de informação do Sistema Único de Saúde (SUS). Foi realizado estudo de coorte histórica de mulheres de 40-69 anos, que realizaram mamografia de rastreamento e exame histopatológico de mama no SUS, nos anos de 2017 a 2019. A taxa de resultados falsos positivos foi estimada a partir da prevalência de resultados BI-RADS alterados na mamografia de rastreamento e da proporção de resultados benignos no exame histopatológico de mama. Das 10.671 mulheres com exame histopatológico no SUS, 46,2% apresentaram resultado benigno, sendo essa proporção significativamente maior em mulheres de 40-49 anos comparada à de mulheres de 50-69 anos. A estimativa de resultados falsos positivos foi de 8,18 casos por 100 mulheres na faixa etária de 40-49 anos, e de 6,06 por 100 mulheres na faixa de 50-69 anos. Essas informações são úteis aos gestores na avaliação de programas de rastreamento do câncer de mama, assim como aos profissionais de saúde, para que orientem a mulher sobre as implicações do rastreamento mamográfico.

False-positive results on mammography screening are common, putting a burden on both women and the health care system. This study aimed to estimate the risk of false-positive results in Brazilian mammography screening based on data from the Brazilian Unified National Health System (SUS) information systems. A retrospective cohort study was conducted with women aged 40-69 years, who underwent mammography screening and breast histopathological examination at SUS from 2017 to 2019. The rate of false-positive results was estimated based on the prevalence of altered BI-RADS results on mammography screening and the proportion of benign results on breast histopathological examination. Of the 10,671 women with histopathological examination at SUS, 46.2% had a benign result, and this proportion was significantly higher in women aged 40-49 years compared to women aged 50-69 years. The estimate of false-positive results was 8.18 cases per 100 women aged 40-49 years and 6.06 per 100 women aged 50-69 years. This information is useful for public managers in evaluating mammography screening programs, as well as for health care providers to guide women on the implications of mammography screening.

Los resultados falsos positivos en la mamografía de cribado son comunes en esta intervención y suponen prejuicios para las mujeres y el sistema de salud. El objetivo de este estudio fue estimar el riesgo de resultados falsos positivos en el cribado mamográfico brasileño a partir de los datos del sistema de información del Sistema Único de Salud (SUS). Se realizó un estudio de cohorte histórica de mujeres de 40-69 años, que se sometieron a mamografía de cribado y examen histopatológico de mama en el SUS, de 2017 a 2019. La tasa de resultados falsos positivos se estimó a partir de la prevalencia de resultados de BI-RADS alterados en la mamografía de cribado y la proporción de resultados benignos en el examen histopatológico de mama. De las 10.671 mujeres que se sometieron a examen histopatológico en el SUS, el 46,2% tuvo un resultado benigno, siendo esta proporción significativamente mayor en mujeres de 40-49 años en comparación con las mujeres de 50-69 años. La estimación de resultados falsos positivos fue de 8,18 casos por 100 mujeres en el grupo de edad de 40-49 años y 6,06 por 100 mujeres en el grupo de 50-69 años. Esta información es útil para los gestores en la evaluación de los programas de cribado de cáncer de mama, así como para los profesionales sanitarios en orientar a las mujeres sobre las implicaciones del cribado mamográfico.

Placenta Accreta Spectrum Prenatal Diagnosis Performance: Are Ultrasound False-positive Results Acceptable in Limited-resources Settings? / Desempenho do diagnóstico pré-natal do espectro da placenta acreta: Os resultados falso-positivos do ultrassom são aceitáveis em ambientes com recursos limitados?

Abstract Objective The immediate referral of patients with risk factors for placenta accreta spectrum (PAS) to specialized centers is recommended, thus favoring an early diagnosis and an interdisciplinary management. However, diagnostic errors are frequent, even in referral centers (RCs). We sought to evaluate the performance of the prenatal diagnosis for PAS in a Latin American hospital. Methods A retrospective descriptive study including patients referred due to the suspicion of PAS was conducted. Data from the prenatal imaging studies were compared with the final diagnoses (intraoperative and/or histological). Results A total of 162 patients were included in the present study. The median gestational age at the time of the first PAS suspicious ultrasound was 29 weeks, but patients arrived at the PAS RC at 34 weeks. The frequency of false-positive results at referring hospitals was 68.5%. Sixty-nine patients underwent surgery based on the suspicion of PAS at 35 weeks, and there was a 28.9% false-positive rate at the RC. In 93 patients, the diagnosis of PAS was ruled out at the RC, with a 2.1% false-negative frequency. Conclusion The prenatal diagnosis of PAS is better at the RC. However, even in these centers, false-positive results are common; therefore, the intraoperative confirmation of the diagnosis of PAS is essential.

Resumo Objetivo Recomenda-se o encaminhamento imediato de pacientes com fatores de risco para espectro placentário acreta (PAS, na sigla em inglês) para centros especializados, favorecendo assim o diagnóstico precoce e o manejo interdisciplinar. No entanto, erros diagnósticos são frequentes, mesmo em centros de referência (CRs). Buscou-se avaliar o desempenho do diagnóstico pré-natal para PAS em um hospital latino-americano. Métodos Um estudo descritivo retrospectivo incluindo pacientes encaminhados por suspeita de SAP foi realizado. Os dados dos exames de imagem do pré-natal foram comparados com os diagnósticos finais (intraoperatórios e/ou histológicos). Resultados Foram incluídos 162 pacientes no presente estudo. A idade gestacional mediana no momento da primeira ultrassonografia suspeita de PAS foi de 29 semanas, mas as pacientes chegaram ao CR de PAS com 34 semanas. A frequência de resultados falso-positivos nos hospitais de referência foi de 68,5%. Sessenta e nove pacientes foram operadas com base na suspeita de PAS com 35 semanas e houve 28,9% de falso-positivos no CR. Em 93 pacientes, o diagnóstico de PAS foi descartado no CR, com frequência de falso-negativos de 2,1%. Conclusão O diagnóstico pré-natal de PAS é melhor no CR. Entretanto, mesmo nestes centros, resultados falso-positivos são comuns; portanto, a confirmação intraoperatória do diagnóstico de SAP é essencial.

Falsos positivos del cribado de trisomía 21 y 18 del primer trimestre y complicaciones obstétricas / Adverse outcomes in pregnancies with false positive trisomy 21 and 18 screening results

OBJETIVO: Analizar si los casos positivos de cribado combinado de trisomía 21 (t21) o trisomía 18 (t18) en ausencia de aneuploidía (falsos positivos- FP) se relacionan con complicaciones de la gestación, ajustando por factores demográficos y clínicos de riesgo. MATERIAL Y MÉTODOS: Estudio retrospectivo de casos y controles anidado en una cohorte de pacientes que acudieron para cribado del primer trimestre. Los casos fueron las pacientes con FP de riesgo combinado de t21 superior a 1/270 o riesgo de t18 superior a 1/100. Se consideraron complicaciones de la gestación: óbito fetal, parto prematuro menor de 34 semanas o prematuro menor de 37 semanas, preeclampsia, retrasos de crecimiento, pequeño para la edad gestacional (CIR, PEG) y diabetes gestacional (DG). Se ajustó por obesidad, edad, paridad, tabaquismo, y técnicas de reproducción asistida. RESULTADO: Se obtuvieron 204 casos de FP, 149 FP para trisomía 21, 41 para trisomía 18, y 14 FP para ambos riesgos. Se encontró asociación estadísticamente significativa de FP t21 con óbito fetal (OR=3,5; ic95% 1,4-8,7; p=0,01), parto prematuro menor de 37 semanas (OR=2,2; IC95% 1,4-3,4; p=0,001), preeclampsia (OR =2,6; IC95% 1,17-6,1; p=0,02), PEG (OR =2,2; IC95% 1,2-4,1; p=0,02), CIR (OR=2,8; IC95% 1,6-5,1; p=0,001), y DG (OR=2,1; IC95% 1,2-3,7; p=0,01). Los FP t18 se asociaron con óbito (OR=8,9; IC95% 2,9-27; p=0,002). CONCLUSIÓN: Los FP del cribado del primer trimestre, para trisomía 21 y trisomía 18, se asocian con resultados obstétricos adversos.

We have studied whether positive cases of combined trisomy 21 (t21) or 18 (t18) screening in the absence of aneuploidy (false positives -FP-) are related to pregnancy complications adjusting for demographic and clinical risk factors. METHODS: Retrospective case-control study nested in a cohort of patients who came for first trimester aneuploidy screening. The cases were patients with FP combined risk of t21 (greater than 1/270) or t18 risk (greater than 1/100). The control group was a sample of patients with low-risk screening. We considered pregnancy complications: stillbirth, premature delivery before 34 and 37 weeks, preeclampsia, growth retardation, small for gestational age (FGR, SGA), and gestational diabetes (GD). Or were adjusted for obesity, age, parity, smoking, and assisted reproduction techniques. RESULTS: 204 cases of FP were obtained, 149 FP for trisomy 21, 41 for trisomy 18, and 14 FP for both risks. A statistically significant association between t21 FP was found with stillbirth (OR = 3.5; 95% CI 1.4-8.7; p = 0.01), preterm delivery less than 37 weeks (OR = 2.2; 95% CI 1.4-3.4; p = 0.001), preeclampsia (OR = 2.6; 95% CI 1.17-6.1; p = 0.02), SGA (OR = 2.2; 95% CI 1, 2-4.1; p = 0.02), FGR (OR = 2.8; 95% CI 1.6-5.1; p = 0.001), and GD (OR = 2.1; 95% CI 1.2 −3.7; p = 0.01). FP t18s were associated with fetal loss (OR= 8.9 (95% CI 2.9-27) p = 0.002. CONCLUSION: FP from first trimester screening for t21 and t18 are associated with adverse obstetric outcomes.

False positive for ß2-transferrin in rhinorrhoea. Ocular trauma. / Un falso positivo para ß2-transferrina en rinorrea. Traumatismo ocular.

Ocular perforations require an action depending on the findings observed. Additionally, the closeness of the orbit to the nasal cavity and the anterior cranial fossa requires any collateral damage in these spaces to be ruled out. The presence of a penetrating ocular injury associated with ipsilateral rhinorrhoea in which the presence of ß2-transferrin -a highly specific and sensitive marker to identify cerebrospinal fluid- is detected, obliges to suspect and locate any possible leakage. A case is presented in which this unbound protein is detected in post-traumatic rhinorrhoea with an origin in the eyeball, making the diagnosis of a CSF leak into a false positive.

Fibroelastic pseudotumor elastofibroma dorsi detected by 18F-FDG PET/CT scan and by postherapy radioiodine SPECT/CT. / Seudotumor fibroelástico elastofibroma dorsi detectado por 18F-FDG PET/TC y por 131I SPECT/TC posterapia.

Radioiodine uptake in the thyroid tissue, metastasis of differentiated thyroid cancer (DTC), and in other tissues, depends on the expression of sodium-iodide symporter (NIS). Vascular permeability, effusions, inflammation, and other mechanisms may also play a role in the accumulation of radioactive iodine. A 63-year-old woman underwent radioiodine therapy, as well as a post-therapy whole-body scan, as she was suspected of having lung metastasis from thyroid carcinoma. The scan not only showed uptake at the lung metastasis but also a faint diffuse bilateral uptake in the posterior thorax. On SPECT/CT this uptake was located in a known Elastofibroma Dorsi (ED) previously diagnosed by contrast CT and viewed in a FDG PET/CT. The radioiodine uptake in ED, especially if typical, is not a diagnostic problem in SPECT/CT study, but can be misleading in a study limited to a few planar images, particularly if the uptake occurs asymmetrically, or ED is located in a unsuspected area.

Pancreatic accessory spleen. False positive with 99mTc-Octreotide.

The case is presented on a patient with abdominal pain and suspicion of neuroendocrine tumor in the tail of the pancreas shown in the abdominal CT and MRI. Whole-body scintigraphy and abdominal SPECT/CT with 99mTc-octreotide were performed that showed a nodular lesion partially on the posterior side of the pancreas tail. This nodule showed faint tracer uptake, and was reported as probable neuroendocrine tumor. Partial pancreatectomy and splenectomy were performed, and the histological study identified the lesion as an ectopic spleen. There are similar cases in the literature that match these findings, but this lesion is still frequently diagnosed after performing unnecessary surgery. When an asymptomatic intrapancreatic mass is detected, an accessory spleen should be considered and specific diagnostic techniques should be performed, such as labeled and denatured red blood cell SPECT/CT.

[Positive urine pneumococcal antigen test and vaccination]. / Antigenuria positiva a neumococo y vacunación.

INTRODUCTION AND OBJECTIVE: Although urine pneumococcal antigen is an useful test, it has false positives such as pneumococcal vaccination. MATERIAL AND METHODS: Positive urine pneumococcal antigen in Hospital de Denia (January-February/2015). We studied epidemiological, radiological and microbiological variables as well as previous pneumococcal vaccination (neumo-23 and/or neumo-13). RESULTS: Urine pneumococcal antigen test was positive in 12.4% of 385 cases. Only 33.3% of positive cases had pneumonia in chest X-ray, and 35.4% of patients had previous pneumococcal vaccination. In most cases (87.5%), an antibiotic was prescribed. CONCLUSIONS: Pneumococcal vaccination can produce a false positive result in the urine pneumococcal antigen test in clinical practice, leading to an unnecessary prescription of antibiotics.

Factors influencing accuracy of referral and the likelihood of false positive referral by optometrists in Bradford, United Kingdom.

AIMS: Levels of false positive referral to ophthalmology departments can be high. This study aimed to evaluate commonality between false positive referrals in order to find the factors which may influence referral accuracy. METHODS: In 2007/08, a sample of 431 new Ophthalmology referrals from the catchment area of Bradford Royal Infirmary were retrospectively analysed. RESULTS: The proportion of false positive referrals generated by optometrists decreases with experience at a rate of 6.2% per year since registration (p<0.0001). Community services which involved further investigation done by the optometrist before directly referring to the hospital were 2.7 times less likely to refer false positively than other referral formats (p=0.007). Male optometrists were about half as likely to generate a false positive referral than females (OR=0.51, p=0.008) and as multiple/corporate practices in the Bradford area employ less experienced and more female staff, independent practices generate about half the number of false positive referrals (OR=0.52, p=0.005). CONCLUSIONS: Clinician experience has the greatest effect on referral accuracy although there is also a significant effect of gender with women tending to refer more false positives. This may be due to a different approach to patient care and possibly a greater sensitivity to litigation. The improved accuracy of community services (which often refer directly after further investigation) supports further growth of these schemes.

Determining decision thresholds and evaluating indicators when conservation status is measured as a continuum.

Categorization of the status of populations, species, and ecosystems underpins most conservation activities. Status is often based on how a system's current indicator value (e.g., change in abundance) relates to some threshold of conservation concern. Receiver operating characteristic (ROC) curves can be used to quantify the statistical reliability of indicators of conservation status and evaluate trade-offs between correct (true positive) and incorrect (false positive) classifications across a range of decision thresholds. However, ROC curves assume a discrete, binary relationship between an indicator and the conservation status it is meant to track, which is a simplification of the more realistic continuum of conservation status, and may limit the applicability of ROC curves in conservation science. We describe a modified ROC curve that treats conservation status as a continuum rather than a discrete state. We explored the influence of this continuum and typical sources of variation in abundance that can lead to classification errors (i.e., random variation and measurement error) on the true and false positive rates corresponding to varying decision thresholds and the reliability of change in abundance as an indicator of conservation status, respectively. We applied our modified ROC approach to an indicator of endangerment in Pacific salmon (Oncorhynchus nerka) (i.e., percent decline in geometric mean abundance) and an indicator of marine ecosystem structure and function (i.e., detritivore biomass). Failure to treat conservation status as a continuum when choosing thresholds for indicators resulted in the misidentification of trade-offs between true and false positive rates and the overestimation of an indicator's reliability. We argue for treating conservation status as a continuum when ROC curves are used to evaluate decision thresholds in indicators for the assessment of conservation status.

Sarcoidosis mimicking metastatic gynaecological malignancies: a diagnostic and therapeutic challenge?

Several case reports describing the coexistence of sarcoidosis and malignancy have been published. Therefore, sarcoidosis should always be considered as a differential diagnosis when a cancer patient develops lymphadenopathy. Positron-emission tomography (PET) 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) combined with computed tomography (CT) is widely used for cancer staging and surveillance because it permits localization of metabolically active malignant tissue. PET/CT or CT findings in patients with suspected cancer recurrence can be used to guide early and aggressive therapy. However, benign hypermetabolic lymphadenopathy can mimic malignant lymphadenopathy, both on a conventional CT scan and on PET/CT. Thus, it is important to obtain a histological diagnosis before initiating antineoplastic therapy based on imaging findings. Four cases of patients affected by gynaecological malignancies and coexisting sarcoidosis are reported in this study. Furthermore, the clinical relevance of making a differential diagnosis between gynaecological cancer recurrence and granulomatous disorder is given specific mention.

From pitfall to misdiagnosis and life-threatening treatment / De las trampas de los falsos positivos a los diagnósticos equivocados y los tratamientos que amenazan la vida

Sixty-four-section multidetector computed tomography angiography (64-SMCTA) is increasingly used for screening and surgical planning of ruptured intracranial aneurysms due to its high sensitivity and positivity and it is less invasive than digital subtraction angiography (DSA). Combination of both is the best tool when diagnosis is inconclusive. Sometimes the use of 64-SMCTA alone may cause interpretation pitfall and unnecessary life-threatening treatment. This case report is about 64-SMCTA interpretation pitfall, a false positive result that occasioned surgery for clipping an intracranial aneurysm which was not found during surgical procedure. The patient survived the life-threatening surgery and she has been doing well over the last two years. A perceptual error and lack of conspicuity due to some limitations of the scanner to disclose a normal anatomic variant were responsible for this false positive. When ever 64-SMCTA renders inconspicuous images, this result must be seen as inconclusive and hence a meticulous differential diagnosis and DSA are required before any surgical planning.

La angiografía mediante tomografía axial computadorizada con multidetectores de 64 secciones (64- SMCTA) se usa cada vez más para el tamizaje y el planeamiento quirúrgico de la ruptura de aneurismas intracraneales, debido a su alta sensibilidad y positividad, y a que es menos invasiva que la angiografía de substracción digital (ASD). La combinación de ambas es la mejor herramienta cuando el diagnóstico es inconcluso. A veces el uso de 64-SMCTA solo, puede causar una interpretación falsamente positiva, llevando así a un tratamiento innecesario que ponga en peligro la vida del paciente. Este reporte de caso trata de una trampa de la interpretación con 64-SMCTA - un resultado falsamente positivo que ocasionó una cirugía para pinzar un aneurisma intracraneal que no se encontró durante el procedimiento quirúrgico. La paciente sobrevivió la riesgosa cirugía, y le ha ido bien en los últimos dos años. Un error de percepción y falta de clara visibilidad a causa de algunas limitaciones del escáner para revelar variantes anatómicas normales, fueron los responsables del falso positivo, es decir, de la falsa alarma. Cuando el 64-SMCTA produce imágenes no suficientemente precisas, el resultado debe considerarse inconcluso, y se requiere entonces un meticuloso diagnóstico diferencial y DSA antes de proseguir a una planificación quirúrgica.