Identifying malignant mesothelioma by a pathological survey using the São Paulo state hospital cancer registry, Brazil.

OBJECTIVE: To review the pathological diagnosis of possible cases and/or hidden cases of malignant mesothelioma (MM) between 2000 and 2012 using the Hospital-Based Cancer Registry database in the state of São Paulo, Brazil. METHODS: Possible cases were retrieved by assessing the database. Inclusion criteria were being older than 30 years of age and having ICD-O-3 topography and morphology codes related to MM. A board of expert pathologists reviewed the pathology reports and requested paraffin blocks in cases that demanded revision. After staining with calretinin, D2-40, WT-1 (as positive MM markers) and Ber-EP4 and MOC31 (as negative MM markers), cases were divided and studied independently by a pair of pathologists to confirm or discard the diagnosis of MM. RESULTS: Our sample comprised 482 cases from 25 hospitals, and 130 needed further histological revision. We received 73 paraffin blocks with adequate material. After board analysis, there were 9 cases with a definitive diagnosis of MM, improving the diagnostic rate in 12%. Two cases of previously diagnosed MM were discarded by review. CONCLUSIONS: Our results confirm that part of MM underdiagnosis and underreporting in Brazil is due to incomplete or mistaken pathological diagnosis.

Mesotheliomas in Children.

Mesotheliomas are rare and aggressive tumors that originate from mesothelial cells. Although exceedingly rare, these tumors may occur in children. Different from adult mesotheliomas, however, environmental exposures particularly to asbestos do not appear to play a major role in mesotheliomas in children, in whom specific genetic rearrangements driving these tumors have been identified in recent years. These molecular alterations may increasingly offer opportunities for targeted therapies in the future, which may provide better outcomes for these highly aggressive malignant neoplasms.

Multicenter study of diffuse pleural mesothelioma. Histopathological and immunohistochemical features.

The pathological diagnosis of diffuse pleural mesothelioma (DPM) contributes to treatment selection and clinical trials interpretation. To know its characteristics and evaluate the viability of comprehensive pathological diagnosis of DPM in Argentina we did a retrospective descriptive study of DPM cases reported from 2009 to 2018. We analyzed 398 cases corresponding to 238 (60%) men and 160 (40%) women, median age 66 years, from surgical biopsies (78%), small biopsies (16.5%) and surgical resections (5.5%). The 77% were epithelioid (E-DPM), 12% biphasic, 10% sarcomatoid, and 4 cases transitional variant. In E-DPM the main pattern was tubular in 36% and solid in 33%. There was a second pattern in 179 cases. Considering the main pattern and the second together, 48% presented tubular subtype and 48% solid subtype. Stroma, necrosis, and nuclear score showed significant differences between E-DPM and non-epithelioid mesotheliomas. Overall tumor grade was predominantly low in E-DPM, except for 42% of the solid main pattern. We recognized the transitional variant extensively in 4 cases and focally in 8. The immunohistochemical antibody panel used included pan-cytokeratin, calretinin, WT-1, cytokeratin 5, CEA and TTF-1. The expression of cytokeratin 5, calretinin and WT-1 was lower in the sarcomatoid type (43%, 87 and 37%) than in the epithelioid type (92%, 98% and 93%). This study highlights the tumor heterogeneity of DPM that shows the diagnostic difficulty, and the feasibility of evaluating histological aggressiveness in E-DPM, B-DPM and S-DPM in our country.

El diagnóstico patológico del mesotelioma pleural difuso (MPD) contribuye a la selección del tratamiento y a la interpretación de los ensayos clínicos. Para conocer sus características y evaluar la viabilidad del diagnóstico patológico de MPD en Argentina se realizó un estudio descriptivo retrospectivo de los casos de MPD informados de 2009 a 2018. Se analizaron 398 casos correspondientes a 238 (60%) hombres y 160 (40%) mujeres, mediana de edad de 66 años, a partir de biopsias quirúrgicas (78%), biopsias pequeñas (16.5%) y resecciones quirúrgicas (5.5%). El 77% fue epitelioide (E-MPD), 12% bifásicos, 10% sarcomatoides y 4 casos variante transicional. En E-MPD se encontró como patrón principal el tubular en 36% y el sólido en 33%. Hubo un segundo patrón en 179 casos. Considerando el principal y el segundo patrón en conjunto, el 48% presentó subtipo tubular y el 48% subtipo sólido. El estroma, la necrosis y el score nuclear mostraron diferencias significativas entre E-MPD y mesoteliomas no epitelioides. El grado general del tumor fue predominantemente bajo en E-MPD, a excepción del 42% del patrón principal sólido. Reconocimos la variante transicional en forma extensa en 4 casos y focalmente en 8. La expresión de citoqueratina 5, calretinina y WT-1 fue menor en el tipo sarcomatoide (43%, 87 y 37%) que en el tipo epitelioide (92%, 98% y 93%). Este estudio destaca la heterogeneidad tumoral de MPD que evidencia la dificu ltad en el diagnóstico y la viabilidad de evaluar la agresividad histológica en E-MPD, B-MPD y S-MPD en nuestro país.

Metastatic papillary mesothelioma in a dog: a case report

A six-year-old female Dachshund presented intense abdominal distension caused by hemorrhagic effusion. Cytological examination of the fluid was performed and suggested a carcinoma. The animal was submitted to exploratory laparotomy and histological examination of the substantially altered spleen revealed epithelioid mesothelioma. Owing to a poor prognosis, poor response to chemotherapy, and development of thoracic effusions that required daily drainages, the owners decided for euthanasia. At necropsy, besides a 600 mL of sera‐hemorrhagic abdominal fluid, no abnormal gross finding was identified in the abdominal cavity. The thoracic cavity was also filled with approximately 200 mL of effusion with same features as those detected in the abdominal fluid. A few firm white-to-gray nodules, with sizes ranging from 0.1 to 0.3 cm, were found in the lungs and diaphragm. Samples of the nodules were stained for routine histopathology and submitted to immunohistochemistry (IHC) assays using the antibodies vimentin, PAN Cytokeratin, calretinin, and TTF-1. Histopathology and IHC findings confirmed the diagnosis of metastatic papillary mesothelioma.

Metastatic papillary mesothelioma in a dog: a case report

A six-year-old female Dachshund presented intense abdominal distension caused by hemorrhagic effusion. Cytological examination of the fluid was performed and suggested a carcinoma. The animal was submitted to exploratory laparotomy and histological examination of the substantially altered spleen revealed epithelioid mesothelioma. Owing to a poor prognosis, poor response to chemotherapy, and development of thoracic effusions that required daily drainages, the owners decided for euthanasia. At necropsy, besides a 600 mL of sera‐hemorrhagic abdominal fluid, no abnormal gross finding was identified in the abdominal cavity. The thoracic cavity was also filled with approximately 200 mL of effusion with same features as those detected in the abdominal fluid. A few firm white-to-gray nodules, with sizes ranging from 0.1 to 0.3 cm, were found in the lungs and diaphragm. Samples of the nodules were stained for routine histopathology and submitted to immunohistochemistry (IHC) assays using the antibodies vimentin, PAN Cytokeratin, calretinin, and TTF-1. Histopathology and IHC findings confirmed the diagnosis of metastatic papillary mesothelioma.(AU)

Synchronous presentation of muscle-invasive urothelial carcinoma of bladder and peritoneal malign mesothelioma

ABSTRACT Introduction Cancer is one of the most important leading cause of death in man and woman in the world. The occurrence of new cancer has become more frequent in recent years due to strict screening protocols and occupational and environmental exposure to carcinogens. The incidence of secondary malignancies has also increased due to close medical follow-up and advanced age. Herein, we report a case and its management diagnosed as synchronous peritoneal malignant mesothelioma and muscle-invasive urothelial carcinoma. Case Description A 71-year-old male presented with macroscopic hematuria and abdominal distension increasing gradually. A contrast enhanced computerized tomography demonstrated bladder mass and diffuse ascites with nodular peritoneal thickening and umbilical mass. He was treated with the multidisciplinary team working including urologist, medical oncologist and general surgeon. Conclusions To our knowledge, this is the first case of peritoneal malign mesothelioma with synchronous muscle-invasive urothelial carcinoma. Because of the rarity of this condition, there is still no consensus on the definitive treatment protocols, yet. Individualized treatment with multidisciplinary close follow-up might improve the survival outcomes.

Synchronous presentation of muscle-invasive urothelial carcinoma of bladder and peritoneal malign mesothelioma.

INTRODUCTION: Cancer is one of the most important leading cause of death in man and woman in the world. The occurrence of new cancer has become more frequent in recent years due to strict screening protocols and occupational and environmental exposure to carcinogens. The incidence of secondary malignancies has also increased due to close medical follow-up and advanced age. Herein, we report a case and its management diagnosed as synchronous peritoneal malignant mesothelioma and muscleinvasive urothelial carcinoma.

Characteristics and long-term outcomes of advanced pleural mesothelioma in Latin America (MeSO-CLICaP).

BACKGROUND: Malignant pleural mesothelioma (MPM) is an aggressive tumor, associated with poor prognosis. There is a lack of information about the clinical and pathological features related with survival in the Latin American population. METHODS: The MeSO-CLICaP registry identified 302 patients with advanced MPM diagnosed and treated between January 2008 and March 2016. The Cox model was applied to determine the variables associated with survival. A random forest tree model was built to predict the response to first-line chemotherapy among Latin American patients. RESULTS: The median age was 61.1 years (SD 10.6 years), 191 (63.2%) were men, 65.9% were ever smokers, and 38.7% had previous exposure to asbestos. A total of 237 (78.5%) had epithelioid tumors, and 188 (62.3%) and 114 (37.7%) cases had stage III or IV MPM, respectively. A total of 49 patients (16.2%) underwent pleurectomy, 57 (18.9%) received radiotherapy, and 279 patients received first-line platinum-based chemotherapy. The overall response rate to first-line chemotherapy was 40.4%, progression-free survival to first-line treatment was 5.7 months (95% CI 4.9-6.5), and 63 (20.8%) patients had pemetrexed maintenance. The median overall survival was 16.8 months (95% CI 13.0-20.5), and multivariate analysis found that stage (P = 0.013), and pleurodesis (P = 0.048), were independent prognostic factors for first-line overall survival. The model to predict response to first-line chemotherapy obtained a 0.98 area under the curve, a sensitivity of 93%, and a specificity of 95% for detecting responders and non-responders. CONCLUSION: This study identifies factors associated with clinical benefit from chemotherapy among advanced MPM Latin American patients, emphasizing the impact of histology and the clinical benefit of chemotherapy on outcomes.

Treatment of malignant pleural mesothelioma with chemotherapy preceding versus after surgical resection.

OBJECTIVES: There are 2 main treatment paradigms recognized by the National Comprehensive Cancer Network for resectable malignant pleural mesothelioma (MPM): induction chemotherapy followed by resection (IC/R), and up-front resection with postoperative chemotherapy (R/PC). These paradigms are being compared in an accruing randomized phase II trial. In the absence of such completed trials, in this study we evaluated overall survival (OS) and postoperative outcomes of IC/R and R/PC. METHODS: The National Cancer Database was queried for newly diagnosed epithelioid/biphasic MPM. Metastatic, node-positive, and/or cT4 disease was excluded, along with nondefinitive surgery and lack of chemotherapy. Multivariable logistic regression ascertained factors independently associated with induction chemotherapy delivery. Kaplan-Meier analysis was used to evaluate OS between cohorts; multivariable Cox proportional hazards modeling was used to assess factors associated with OS. Survival was also evaluated between propensity-matched populations. Last, postoperative outcomes were assessed between groups. RESULTS: Overall, 361 patients (182 IC/R, 179 R/PC) were analyzed. Temporal trends revealed that IC/R is decreasing over time. Survival of the IC/R cohort was similar to that of R/PC patients (20.9 vs 21.7 months; P = .500); this persisted after propensity matching (20.8 vs 22.0 months; P = .270). However, patients who underwent IC/R experienced longer postoperative hospitalization (median 7 days vs 6 days; P = .001) and higher 30-day mortality (3.3% vs 0%; P = .020). CONCLUSIONS: To our knowledge, this is the only comparative investigation of the 2 major management paradigms of operable MPM. IC/R regimens are decreasing over time in the United States. Although associated with survival similar to R/PC, IC/R might be associated with worse postoperative outcomes. Careful induction chemotherapy patient selection is thus highly recommended.

Survival by Histologic Subtype of Malignant Pleural Mesothelioma and the Impact of Surgical Resection on Overall Survival.

INTRODUCTION: For the 3 histologic subtypes of malignant pleural mesothelioma (MPM)-epithelioid, sarcomatoid, and biphasic-the magnitude of benefit with surgical management remains underdefined. MATERIALS AND METHODS: The National Cancer Data Base was queried for newly diagnosed nonmetastatic MPM with known histology. Patients in each histologic group were dichotomized into those receiving gross macroscopic resection versus lack thereof/no surgery. Kaplan-Meier analysis evaluated overall survival (OS) between cohorts; multivariable Cox proportional hazards modeling assessed factors associated with OS. After propensity matching, survival was evaluated for each histologic subtype with and without surgery. RESULTS: Overall, 4207 patients (68% epithelioid, 18% sarcomatoid, 13% biphasic) met the study criteria. Before propensity matching, patients with epithelioid disease experienced the highest median OS (14.4 months), followed by biphasic (9.5 months) and sarcomatoid (5.3 months) disease; this also persisted after propensity matching (P < .001). After propensity matching, surgery was associated with significantly improved OS for epithelioid (20.9 vs. 14.7 months, P < .001) and biphasic (14.5 vs. 8.8 months, P = .013) but not sarcomatoid (11.2 vs. 6.5 months, P = .140) disease. On multivariable analysis, factors predictive of poorer OS included advanced age, male gender, uninsured status, urban residence, treatment at community centers, and T4/N2 disease (all P < .05). Chemotherapy and surgery were independently associated with improved OS, as was histology (all P < .001). CONCLUSION: This large investigation evaluated surgical practice patterns and survival by histology for MPM and found that histology independently affects survival. Gross macroscopic resection is associated with significantly increased survival in epithelioid and biphasic, but not sarcomatoid, disease. However, the decision to perform surgery should continue to be individualized in light of available randomized data.

Secreted and Tissue miRNAs as Diagnosis Biomarkers of Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare but aggressive tumor that originates in the pleura, is diagnosed in advanced stages and has a poor prognosis. Accurate diagnosis of MPM is often difficult and complex, and the gold standard diagnosis test is based on qualitative analysis of markers in pleural tissue by immunohistochemical staining. Therefore, it is necessary to develop quantitative and non-subjective alternative diagnostic tools. MicroRNAs are non-coding RNAs that regulate essential cellular mechanisms at the post-transcriptional level. Recent evidence indicates that miRNA expression in tissue and body fluids is aberrant in various tumors, revealing miRNAs as promising diagnostic biomarkers. This review summarizes evidence regarding secreted and tissue miRNAs as biomarkers of MPM and the biological characteristics associated with their potential diagnostic value. In addition to studies regarding miRNAs with potential diagnostic value for MPM, studies that aimed to identify the miRNAs involved in molecular mechanisms associated with MPM development are described with an emphasis on relevant aspects of the experimental designs that may influence the accuracy, consistency and real diagnostic value of currently reported data.

Recent Advances in the Diagnosis of Malignant Mesothelioma: Focus on Approach in Challenging Cases and in Limited Tissue and Cytologic Samples.

Mesothelial proliferations can be diagnostically challenging in small specimens, such as body fluid cytology and small tissue biopsies. A great morphologic challenge for pathologists is the separation of benign reactive mesothelial proliferations from malignant mesotheliomas. Reactive mesothelial proliferations may have histologic features that resemble malignancy including increased cellularity, cytologic atypia, and mitoses. Recent advances in mesothelioma genetics resulted in identification of BAP1 mutations and p16 deletions as features of malignant mesotheliomas. Hence, BAP1 immunohistochemistry and fluorescence in situ hybridization for p16 emerged as 2 most common diagnostically helpful ancillary studies used on limited samples when the question is whether the proliferation is malignant or benign. In contrast, separation of mesothelioma from other malignancies is relatively straight forward using morphology and immunohistochemical stains. The choice of antibody panel to be applied in an individual case is driven by morphology, either epithelioid or sarcomatoid. This brief review will focus on morphology and ancillary testing of mainly pleural mesothelial proliferations.

A panel of markers for identification of malignant and non-malignant cells in culture from effusions.

The aim of the present study was to identify cell types in primary culture from malignant and non-malignant effusions. Effusion samples were subjected to cytology and culture. Immunocytochemistry was performed in cytological slides to evaluate malignancy (positivity for malignancy markers) and in culture slides for identification of cell types in growth. A total of 143 effusion samples (pleural n=76; peritoneal n=37; pericardial n=4; and peritoneal lavage n=26) were analyzed. Cell growth was observed in 34.9% of all samples and immunocytochemistry for identification of cell types in culture slides was conclusive in 90% of them. In non-malignant samples (n=28), growth of mesothelial cells, macrophages and of both cell types was identified in 82.14, 10.71 and 7.14%, respectively. In malignant samples (n=17, all carcinomas), growth of malignant epithelial cells and of both malignant epithelial and mesothelial cells was identified in 41.17 and 23.52%, respectively. In the remaining 35.29% of malignant samples, the only cells in growth were mesothelial and/or macrophages instead of malignant epithelial cells. In conclusion, in culture of malignant effusions, mesothelial cells may be simultaneously identified with malignant epithelial cells. Besides, mesothelial cells and macrophages may be the only cells identified in malignant effusion culture. Therefore, a broad panel of cell markers should be used for unmistakable identification of cells in studies of effusion primary culture. The ideal malignant effusion sample to obtain culture of neoplastic cells should be that without the presence of mesothelial cells and macrophages.

Mesotelioma Peritoneal Maligno. Presentación de un caso / Malignant Peritoneal Mesothelioma. Case presentation

El mesotelioma es un tumor poco frecuente, sobretodo en localización peritoneal. Originado en las células mesoteliales de superficies serosas. Su etiología es desconocida, aunque en muchos casos se relaciona con exposición a asbestos. Su frecuencia va en aumento en los últimos años, tiene mayor incidencia en varones de edad media. Se presentó un paciente de 73 años diabético e hipertenso que llevaba 21 días con sensación de llenura, aumento de volumen del abdomen, decaimiento marcado, pérdida del apetito. En este período presentó una pérdida de peso corporal de 10 kilos. Por todo lo anterior se decidió su ingreso para estudio y tratamiento (AU).

The mesothelioma is a little frequent tumor, especially in peritoneal location, originated in the mesothelial cells of serous surfaces. Its etiology is unknown, although in many cases it is related with exposition to asbestos. Its frequency increases in the last years, showing higher incidence in medium-age male people. The case of a diabetic, hypertensive patient aged 73 years was presented. He was already 21 days feeling bloating, having increase of the abdominal volume, remarked weakness, appetite loss. In this period he had a body weight loss of 10 kg. For that all, his admission was decided for study and treatment (AU).

Mesotelioma Peritoneal Maligno. Presentación de un caso / Malignant Peritoneal Mesothelioma. Case presentation

El mesotelioma es un tumor poco frecuente, sobretodo en localización peritoneal. Originado en las células mesoteliales de superficies serosas. Su etiología es desconocida, aunque en muchos casos se relaciona con exposición a asbestos. Su frecuencia va en aumento en los últimos años, tiene mayor incidencia en varones de edad media. Se presentó un paciente de 73 años diabético e hipertenso que llevaba 21 días con sensación de llenura, aumento de volumen del abdomen, decaimiento marcado, pérdida del apetito. En este período presentó una pérdida de peso corporal de 10 kilos. Por todo lo anterior se decidió su ingreso para estudio y tratamiento (AU).

The mesothelioma is a little frequent tumor, especially in peritoneal location, originated in the mesothelial cells of serous surfaces. Its etiology is unknown, although in many cases it is related with exposition to asbestos. Its frequency increases in the last years, showing higher incidence in medium-age male people. The case of a diabetic, hypertensive patient aged 73 years was presented. He was already 21 days feeling bloating, having increase of the abdominal volume, remarked weakness, appetite loss. In this period he had a body weight loss of 10 kg. For that all, his admission was decided for study and treatment (AU).

The PD-L1/PD-1 pathway promotes dysfunction, but not "exhaustion", in tumor-responding T cells from pleural effusions in lung cancer patients.

Malignant pleural effusions are frequent in patients with advanced stages of lung cancer and are commonly infiltrated by lymphocytes and tumor cells. CD8+ T cells from these effusions have reduced effector functions. The programmed death receptor 1(PD-1)/programmed death ligand 1 (PD-L1) pathway is involved in T-cell exhaustion, and it might be responsible for T-cell dysfunction in lung cancer patients. Here, we show that PD-L1 is expressed on tumor cell samples from malignant effusions, on lung cancer cell lines, and, interestingly, on MRC-5 lung fibroblasts. PD-L1 was up-regulated in lung cancer cell lines upon treatment with IFN-gamma, but not under hypoxic conditions, as detected by RT-qPCR and flow cytometry. Blockade of PD-L1 on tumor cells restored granzyme-B expression in allogenic CD8+ T cells in vitro. Remarkably, pleural effusion CD8+ T cells that responded to the tumor antigens MAGE-3A and WT-1 (identified as CD137+ cells) were lower in frequency than CMV pp65-responding CD8+ T cells and did not have an exhausted phenotype (PD-1+ TIM-3+). Nonetheless, tumor-responding CD8+ T cells had a memory phenotype and expressed higher levels of PD-1. A PD-L1 blocking antibody increased the expression of granzyme-B and perforin on polyclonal- and tumor-stimulated CD8+ T cells. Taken together, our data show that rather than being exhausted, tumor-responding CD8+ T cells are not completely differentiated into effector cells and are prone to negative regulation by PD-L1. Hence, our study provides evidence that lung cancer patients respond to immunotherapy due to blockade of the PD-L1/PD-1 pathway.

Expression Profiles of Cytokine mRNAs in the Pleural Fluid Reveal Differences Among Tuberculosis, Malignancies, and Pneumonia-Exudative Pleural Effusions.

INTRODUCTION: Tuberculosis (TB) and malignant diseases are the most common causes of lymphocytic pleural effusion in adults. Serum and pleural fluid cytokine levels have been analyzed to help in the differential diagnosis, but with limited results. PURPOSE: This study investigates transcription levels of selected cytokine genes in pleural effusion of patients under investigation for TB. METHODS: This was a prospective study that included adult patients under investigation for pleural effusion in Brazil. The expression of 19 cytokine genes was analyzed by RT-qPCR. RESULTS: The majority of cytokine-related genes expressed in pleural fluid of TB patients were similar in non-TB patients, except for RORA and RORC genes, which showed a statistically higher level in TB. All cytokines in the Th17 pattern were induced in TB patients' pleural fluid. Patients with malignant pleural effusion expressed higher levels of IFN-α1, IFN-ß1, TNF-α, IL-4 and IL-6, and suppression of TGFß-1. CONCLUSION: There is still a lot to understand about the cytokine roles in the pro- and anti-inflammatory environment of exudative pleural effusions. The data presented here showed an increased expression of Th17 pattern cytokines genes in TB patients that could be used as markers to differentiate tuberculous pleuritis from other common causes of exudative pleural effusion.

Mesotelioma bem diferenciado (benigno) de túnica vaginal: relato de um caso e revisão da literatura / Well-differentiated (benign) mesothelioma of the tunica vaginalis: report of a case and literature review

Mesoteliomas são tumores oriundos das células mesoteliais da pleura, peritônio, pericárdio ou túnica vaginal, sendo a exposição prolongada ao asbesto o principal fator de risco. Neoplasias mesoteliais benignas da região paratesticular são raras. Relata-se um caso de Mesotelioma de Túnica Vaginal associado à hidrocele, destacando a utilidade da ecografia na avaliação das massas escrotais (AU)

Mesotheliomas are tumors originating from the mesothelial cells of the pleura, peritoneum, pericardium or tunica vaginalis, with prolonged exposure to asbestos the main risk factor. Benign mesothelial neoplasms of the paratesticular region are rare. Here we report a case of tunica vaginalis mesothelioma associated with hydrocele, highlighting the usefulness of ultrasound in the evaluation of scrotal masses (AU)