Delayed-Phase Enhancement for Evaluation of Malignant Pleural Mesothelioma on Computed Tomography: A Prospective Cohort Study.

BACKGROUND: Radiologic assessment of malignant pleural mesothelioma (MPM) on computed tomography (CT) imaging can be limited by similar attenuations of MPM and adjacent tissues. This can result in inaccuracies in defining the presence and extent of pleural tumor burden. We hypothesized that increasing the time delay for pleural enhancement will optimize discrimination between MPM and noncancerous tissues on CT. Here we conduct a prospective observational study to determine the optimal time delay for imaging MPM on CT. PATIENTS AND METHODS: Adult MPM patients (n = 15) were enrolled in this prospective exploratory imaging trial. Patients with < 1 cm MPM thickness, prior pleurectomy, pleurodesis, pleural radiotherapy, or antiangiogenic therapy were excluded. All patients underwent a dynamically-enhanced CT with multiple time delays (0 - 10 minutes) after intravenous contrast administration. Tumor tissue attenuation was measured at each phase of enhancement. A qualitative assessment of tumor enhancement kinetics was also performed. The optimal phase of enhancement based on qualitative lesion conspicuity and quantitative tumor enhancement was then compared. RESULTS: MPM tumor enhancement was quantitatively and qualitatively increased at time delays beyond the conventional time delay for thoracic CT imaging (40-60 seconds). Patient tumor enhancement kinetics, displayed as the fraction of maximal tumor tissue attenuation as a function of time, revealed an optimal time delay of 230 to 300 seconds after intravenous contrast administration. There was an association between degree of tumor enhancement and subjective lesion conspicuity. CONCLUSION: Optimal MPM contrast enhancement occurs at a later phase than typically acquired with conventional thoracic CT imaging.

Mesotelioma pleural maligno: a propósito de un caso / Malignant pleural mesothelioma: a case report

El mesotelioma difuso es una neoplasia maligna poco frecuente que proviene de las células mesoteliales; la pleura es su localización más habitual y se estima que un 10% de los casos se localizan a nivel peritoneal. El mesotelioma es habitualmente diagnosticado en la quinta década de la vida, con un claro predominio en el sexo masculino, debido esto último a su relación con la exposición laboral al asbesto. Se expone un caso con factores de riesgo y diagnóstico asociado. (AU)

Diffuse mesothelioma is a rare malignant neoplasm that comes from mesothelial cells; the pleura are the most common location and is estimated that 10% of the cases are located at the peritoneal level. Mesothelioma is usually diagnosed in the fifth decade of life, with a clear predominance in the male sex, due to its relation to occupational exposureto asbestos. A case is presented with risk factors and associated diagnosis. (AU)

Biodistribution and Tumor Uptake of 67Ga-Nimotuzumab in a Malignant Pleural Mesothelioma Xenograft.

Malignant pleural mesothelioma (MPM) is the most common tumor of the pulmonary pleura. It is a rare and aggressive malignancy, generally associated with continuous occupational exposure to asbestos. Only a multimodal-approach to treatment, based on surgical resection, chemotherapy and/or radiation, has shown some benefits. However, the survival rate remains low. Nimotuzumab (h-R3), an anti-EGFR (epidermal growth factor receptor) humanized antibody, is proposed as a promising agent for the treatment of MPM. The aim of this research was to implement a procedure for nimotuzumab radiolabeling to evaluate its biodistribution and affinity for EGF (epidermal growth factor) receptors present in a mesothelioma xenograft. Nimotuzumab was radiolabeled with 67Ga; radiolabel efficiency, radiochemical purity, serum stability, and biodistribution were evaluated. Biodistribution and tumor uptake imaging studies by microSPECT/CT in mesothelioma xenografts revealed constant nimotuzumab uptake at the tumor site during the first 48 h after drug administration. In vivo studies using MPM xenografts showed a significant uptake of this radioimmunoconjugate, which illustrates its potential as a biomarker that could promote its theranostic use in patients with MPM.

Applications of Magnetic Resonance Imaging of the Thorax in Pleural Diseases: A State-of-the-Art Review.

The aim of this review was to present the main aspects of pleural diseases seen with conventional and advanced magnetic resonance imaging (MRI) techniques. This modality is considered to be the gold standard for the evaluation of the pleural interface, characterization of complex pleural effusion, and identification of exudate and hemorrhage, as well as in the analysis of superior sulcus tumors, as it enables more accurate staging. The indication for MRI of the thorax in the identification of these conditions is increasing in comparison to computerized tomography, and it can also be used to support the diagnosis of pulmonary illnesses. This literature review describes the morphological and functional aspects of the main benign and malignant pleural diseases assessed with MRI, including mesothelioma, metastasis, lymphoma, fibroma, lipoma, endometriosis, asbestos-related pleural disease, empyema, textiloma, and splenosis.

Malignant Pleural Mesothelioma: Accuracy of CT Against Immunohistochemical Test Among the Mexican Population.

BACKGROUND AND AIMS: Malignant pleural mesothelioma (MPM) is associated with occupational and environmental exposure to asbestos. The incidence is expected to increase as the use of asbestos is not prohibited in many countries, such as in Mexico. We undertook this study to determine sensitivity, specificity, predictive values and likelihood ratios of computed tomography (CT) in a sample from Mexican population with suspected MPM and other pleuropulmonary diseases. METHODS: CT films of 38 patients suspected of having MPM were analyzed. A single observer was blinded to MPM diagnoses. The frequencies of ten CT findings were identified. A cut-off point of ≥5 CT findings was established to determine high MPM probability. Sensitivity, specificity, predictive values and likelihood ratio of the CT against biopsy using immunohistochemical testing (IHC) for MPM were calculated. RESULTS: Of the 38 patients, 31 had MPM and seven had lung adenocarcinoma. The five key findings were mediastinal pleural thickening 96.7% (n = 30), nodular pleural thickening 93.3% (n = 29), pleural mass 83.9% (n = 26), diminished lung 70.9% (n = 22) and contracted hemithorax 70.9% (n = 22). Sensitivity 96.8% (83.2-99.4), specificity 85.7% (42.2-97.6), positive likelihood ratio 6.7 (1.1-41.6), and negative likelihood ratio of 0.04 (0.01-0.2) were reported. CONCLUSIONS: Sensitivity and specificity in this study was greater than previously reported, 96.8% and 85.7 vs. 93.2 and 65.6%, respectively. CT is an easily accessible and useful tool that should be incorporated into the medical education of general physicians to improve MPM diagnosis of suspected cases.

[Pulmonary disease due to asbestos in steel industry workers]. / Enfermedad pulmonar por amianto en trabajadores de acería.

Asbestos-related diseases are caused by the inhalation of asbestos fibers in their variety chrysotile or white asbestos. Although the ban in Argentina dates from 2003, there are numerous industries where work continues with this mineral, including iron and steel industries. It is currently known the high pathogenicity of this material, so that in many countries there are programs to monitoring the exposed workers. Here we describe the general characteristics and pulmonary manifestations in 27 patients who had worked in a very huge steel factory in South America. The diagnosis of asbestos-related diseases was made by a medical-occupational record, history of asbestos exposure, additional studies of lung function and chest images. Then the sources of exposure (occupational, domestic and environmental), exposure time and latency period were analyzed, in those patients in whom a related disease was detected. Smoking history was also taken into account. Twenty-two patients had benigns pathologies (81.4%), sixteen of them with lesions localyzed in pleura, and other six pulmonary asbestosis. The malignant pathologies occurred in five patients (18.5%), in four of them mesothelioma and in other one lung cancer. The problem of asbestos exposure has contemporary relevance. Hence the need for a surveillance program in workers exposed to asbestos in the past or currently, to detect, report, record and investigate the characteristics of these pathologies.

Enfermedad pulmonar por amianto en trabajadores de acería / Pulmonary disease due to asbestos in steel industry workers

Las enfermedades relacionadas al amianto se producen por la inhalación de fibras de asbestos en su variedad crisotilo o amianto blanco. A pesar de que en la Argentina la prohibición data del año 2003, existen numerosas industrias donde se sigue trabajando con este mineral, entre ellas las metalúrgicas y acerías. Actualmente se conoce la alta patogenicidad de este material, por lo que en muchos países existen programas de seguimiento de los trabajadores expuestos. Se describen las características generales y manifestaciones clínicas pulmonares de 27 pacientes que trabajaron en una gran acería de América del Sur. El diagnóstico de amiantopatías se realizó mediante historia clínica laboral, antecedente de exposición al amianto, estudios complementarios de función pulmonar e imágenes del tórax. Se analizaron la fuente de exposición (laboral, doméstica y ambiental), tiempo de exposición y período de latencia en los pacientes de los cuales se detectó enfermedad relacionada. Los antecedentes de tabaquismo fueron tenidos en cuenta para el análisis. En 22 pacientes se presentaron patologías benignas (81.4%), 16 de ellos tenían lesiones exclusivamente pleurales y otros 6 asbestosis. Las patologías malignas se presentaron en 5 pacientes (18.5%), en 4 fueron mesoteliomas y en uno carcinoma pulmonar. El problema de la exposición al amianto tiene vigencia actual. De ahí la necesidad de un programa de vigilancia en trabajadores expuestos al amianto actualmente o en el pasado, para detectar, notificar, registrar e investigar las características de estas patologías.(AU)

Asbestos-related diseases are caused by the inhalation of asbestos fibers in their variety chrysotile or white asbestos. Although the ban in Argentina dates from 2003, there are numerous industries where work continues with this mineral, including iron and steel industries. It is currently known the high pathogenicity of this material, so that in many countries there are programs to monitoring the exposed workers. Here we describe the general characteristics and pulmonary manifestations in 27 patients who had worked in a very huge steel factory in South America. The diagnosis of asbestos-related diseases was made by a medical-occupational record, history of asbestos exposure, additional studies of lung function and chest images. Then the sources of exposure (occupational, domestic and environmental), exposure time and latency period were analyzed, in those patients in whom a related disease was detected. Smoking history was also taken into account. Twenty-two patients had benigns pathologies (81.4%), sixteen of them with lesions localyzed in pleura, and other six pulmonary asbestosis. The malignant pathologies occurred in five patients (18.5%), in four of them mesothelioma and in other one lung cancer. The problem of asbestos exposure has contemporary relevance. Hence the need for a surveillance program in workers exposed to asbestos in the past or currently, to detect, report, record and investigate the characteristics of these pathologies.(AU)

[Malignant mesothelioma risk factors: experience in the General Hospital of Mexico]. / Mesotelioma maligno: factores de riesgo, experiencia en el Hospital General de México.

BACKGROUND: Malignant mesothelioma is a neoplasm of bad prognosis, it is linked with asbestos contact, but there are cases without this antecedent. OBJECTIVE: To investigate the relationship of asbestos exposition and other factors with malignant mesothelioma. METHODS: Retrospective analysis of histologic confirmed cases of malignant mesothelioma, neoplasic familiar history, tobacco smoking, exposure to wood smoke and to asbestos, were annotated in a paired case/control study 1: 1-3 with logistic regression model to identify risk factors for OR. RESULTS: 61 cases of malignant mesothelioma were confirmed by histopathologic study, 41 male and 20 female. Mean age was 56 years ± 13 years; 56 cases (91.8%) correspond to epithelial malignant mesothelioma, three sarcomatous (4.9%) one desmoplastic and one biphasic. One in eight (13.1%) had exposure to asbestos. Model of logistic regression with four variables: history of familiar cancer, tobacco smoking, wood smoke and asbestos exposition, the the last one with an OR= 3.083 and p > 0.05. No other variables found to be a risk factor for malignant mesothelioma. CONCLUSIONS: Exposure to asbestos is a risk factor for malignant mesothelioma, which is confirmed in this study, however it is important to extend the investigation of other possible causal factors of this disease.

Antecedentes: el mesotelioma maligno es un tumor de mal pronóstico relacionado con el contacto con asbesto; sin embargo, existen numerosos casos sin este antecedente. Objetivo: describir la relación entre la exposición al asbesto y otros factores con el mesotelioma maligno. Material y métodos: estudio retrospectivo de casos y controles pareado 1: 1-3 por edad y sexo de pacientes con diagnóstico de mesotelioma maligno. Se registraron: la exposición al asbesto, tabaco, humo de leña y antecedentes familiares de cáncer. Se empleó regresión logística para razones de momios (ORs). Resultados: se estudiaron 61 casos con mesotelioma maligno, 41 hombres y 20 mujeres. La edad promedio fue 56 ± 13 años; 56 casos fueron mesotelioma maligno epitelial (91.8%), tres sarcomatosos (4.9%), uno desmoplásico y uno bifásico. Sólo en 8 (13.1%) se identificó exposición al asbesto. En el modelo de regresión logística el asbesto tuvo una razón de momios de 3.083 p > 0.05. Ninguna otra variable resultó ser un factor de riesgo para mesotelioma maligno. Conclusiones: la exposición al asbesto es un factor de riesgo para mesotelioma maligno, lo que se confirma en este estudio; sin embargo, es importante ampliar la investigación de otros posibles factores causales de esta enfermedad.

Enfermedad pulmonar por amianto en trabajadores de acería. / [Pulmonary disease due to asbestos in steel industry workers].

Asbestos-related diseases are caused by the inhalation of asbestos fibers in their variety chrysotile or white asbestos. Although the ban in Argentina dates from 2003, there are numerous industries where work continues with this mineral, including iron and steel industries. It is currently known the high pathogenicity of this material, so that in many countries there are programs to monitoring the exposed workers. Here we describe the general characteristics and pulmonary manifestations in 27 patients who had worked in a very huge steel factory in South America. The diagnosis of asbestos-related diseases was made by a medical-occupational record, history of asbestos exposure, additional studies of lung function and chest images. Then the sources of exposure (occupational, domestic and environmental), exposure time and latency period were analyzed, in those patients in whom a related disease was detected. Smoking history was also taken into account. Twenty-two patients had benigns pathologies (81.4

), sixteen of them with lesions localyzed in pleura, and other six pulmonary asbestosis. The malignant pathologies occurred in five patients (18.5

), in four of them mesothelioma and in other one lung cancer. The problem of asbestos exposure has contemporary relevance. Hence the need for a surveillance program in workers exposed to asbestos in the past or currently, to detect, report, record and investigate the characteristics of these pathologies.

Giant solitary fibrous tumor of the pleura.

BACKGROUND: Solitary fibrous tumor is the second primary malignancy of the pleura and can reach up to 39 cm in diameter; however, to be referred to as 'giant' it must occupy at least 40% of the affected hemithorax. Although this tumor usually shows a benign behavior, malignancy criteria have been described. The aim of the study was to assess the initial evaluation, diagnostic procedures, surgical management, treatment outcome, and prognosis. METHODS: We performed a descriptive, observational, longitudinal, and retrospective study from 2002 to 2006 on patients who underwent surgery with a diagnosis of giant solitary fibrous tumor of the pleura. RESULTS: Six patients were included; 83.3% were females. Mean age was 48 years. All patients were symptomatic, mainly dyspnea, cough and chest pain; 66.7% were left-sided. Preoperative angiography and embolization were performed in 83.3% cases with successful surgical resection. The predominant blood supply was derived from the internal mammalian artery. Intraoperative complication rate was 17%. A vascular pedicle was found in 66.7%. The largest lesion was 40 cm in diameter and weighed 4500 g. Only one case showed high mitotic activity. Mean follow-up to date is 14 months. CONCLUSIONS: Symptomatology found was consistent with previous reports but in higher percentages. Accurate diagnosis is critical because surgical resection involves a potential cure; however, long-term follow-up is mandatory. Preoperative embolization is recommended due to tumor size.

[Pleural mesothelioma in a Mexican population: clinical and radiological similarities among histopathologic patterns]. / Mesotelioma pleural. Similitudes clínico-radiológicas entre estirpes.

OBJECTIVE: To describe clinical and radiological features of patients with pleural mesothelioma, according to main histological types. METHODS: Clinical records of inpatients admitted with diagnosis of pleural mesothelioma to the Instituto Nacional de Enfermedades Respiratorias in the last 11 years, were reviewed. RESULTS: We analyzed 85 cases confirmed by immunohistochemistry. The most frequent histological type was epithelial (84.7 %), followed by sarcomatous (12.9 %) and mixed (2.4 %) types. Comparison between epithelial and sarcomatous types showed no differences in age (53.7 +/- 13.1 vs. 55.9 +/- 11.0 years, respectively), male : female ratio (2.3 : 1 vs. 1.8 : 1), history of asbestos exposure (34.7 vs. 27.2 %), tobacco habit (54.2 vs 45.4 %), occupation, evolution time (4.8 +/- 3.3 vs. 4.4 +/- 3.7 months), pain, dyspnea and cough, right-side predominance (55.6 vs. 81.8 %), radiological image with pleural effusion (59.7 vs. 36.4 %) or pleural thickening (38.9 vs. 63.6 %), and diagnostic efficiency of closed pleural biopsy (58.3 vs. 27.2 %). CONCLUSIONS: Our results suggest that clinical and radiological features of epithelial and sarcomatous histological types are very similar. Additionally, we found a high frequency of epithelial mesothelioma, which contrasts with findings from other countries, suggesting that the type of asbestos or other factors involved in the development of pleural mesothelioma differ from those existing in other regions of the world.

[Malignant mesothelioma: clinical and radiological description of 45 cases with and without asbestos exposure]. / Mesotelioma maligno: descripción clínica y radiológica de 45 casos con y sin exposición a asbestos.

OBJECTIVE: Our aim was to identify and describe the main symptoms, clinical presentation, and radiographic changes in malignant mesothelioma (MM) patients. MATERIAL AND METHODS: We reviewed the medical and X-ray records of all patients diagnosed with MM, admitted between 1991 and 1998 to the National Institute of Respiratory Diseases (INER), which is a governmental institution specialized in chest disease in Mexico City. The following data were collected: Age, occupation, asbestos exposure, latency, family history of cancer, clinical symptoms, and X-ray changes. Data are presented as percentages by sex and age group. RESULTS: We found 45 cases of MM; in 80% of them a history of asbestos exposure could not be documented. The 51-60 years age group had the highest frequency of MM. Dispnea and chest pain were the presenting symptoms in most patients. Pleural effusion and pleural thickening were the X-ray abnormalities observed in 75% of the patients. CONCLUSIONS: The clinical and radiographic findings among patients with MM without asbestos exposure were similar to those with a history of asbestos exposure.