The panorama of different faces of mesothelial cells

All effusions in serous cavities represent a pathologic processes secondary to inflammatory, neoplastic, hemodynamic, or mechanical/traumatic etiologies. This elicits reactive changes in the extremely sensitive mesothelial cells lining the serosal surfaces. The result is hypertrophy and hyperplasia which lead to broad changes with a wide range of morphological appearances. These reversible alterations may resolve entirely after the recovery of underlying pathology. Under the tertiary care situations, neoplastic effusion specimens are encountered more frequently. Although some non-neoplastic pathologic process may demonstrate a few diagnostic features, cytologic evaluation of malignant effusions usually show diagnostic malignant cells. However, the most versatile mesothelial cells demonstrate a very wide cytomorphological spectrum secondary to reactive challenges. These mesothelial cells are usually referred to as ‘reactive mesothelial cells’. In addition other terms such as reactive mesothelial proliferation, reactive mesothelial hyperplasia, irritated mesothelial cells, activated mesothelial cells, hyperplastic mesothelial cells, hypertrophic mesothelial cells, and proliferative mesothelial cells. Rarely atypical mesothelial cells, although not recommended, is used inadvertently. Although there is a lack of general agreement defining these terms, some of these including atypical mesothelial cells, should not be preferred. With reference to this CMAS series, usually favored term ‘reactive mesothelial cells’ is preferred. The size of reactive mesothelial cells range from 15 to 30 µm (but may be up to 50 µm). These polyhedral cells with variable amount of cytoplasm and enlarged nuclei may show variation in sizes and shapes with conspicuous nucleoli. Bi- and multi-nucleation is frequent. Cohesive groups of mesothelial cells as sheets and three dimensional groups may be present. Some floridly reactive mesothelial cells with hyperchromatic enlarged nuclei with prominent nucleoli and scant cytoplasm may resemble malignant cells. This astonishingly wide morphological spectrum of reactive mesothelial cells is a significant interpretation challenge in effusion fluid cytology. Methodical interpretation approach with appropriate knowledge about this wide spectrum is important aspect in diagnostic cytopathology of effusion fluids.

Renal cell carcinoma with malignant pleural effusion: Case report and systematic review of literature

Introduction: Renal cell carcinoma metastasizes commonly to visceral organs such as adrenals, liver, lungs, or to bones. Metastases to body cavities such as pleura, pericardium and peritoneum are rare, and almost never in isolation. Case discussion: We discuss here a patient who was diagnosed with renal cell carcinoma following an episode of hematuria and underwent radical nephrectomy for the same. Within a month of surgery, he was evaluated for sudden onset breathlessness and detected to have massive left-sided pleural effusion, which returned malignant on pleural biopsy. The patient was treated with oral multikinase inhibitor following symptomatic therapy, with a favorable response. The imaging findings and relevant literature exploring the incidence of such presentations are discussed. Conclusion: Malignant effusions usually portend a poor prognosis but owing to the rarity of this condition and availability of newer therapies, long-term durable control may be expected.

Overuse of small chest drains for pleural effusions: a retrospective practice review

PurposeSmall-bore drains (≤ 16 Fr) are used in many centers to manage all pleural effusions. The goal of this study was to determine the proportion of avoidable chest drains and associated complications when a strategy of routine chest drain insertion is in place.Design/methodology/approachWe retrospectively reviewed consecutive pleural procedures performed in the Radiology Department of the McGill University Health Centre over one year (August 2015–July 2016). Drain insertion was the default drainage strategy. An interdisciplinary workgroup established criteria for drain insertion, namely: pneumothorax, pleural infection (confirmed/highly suspected), massive effusion (more than 2/3 of hemithorax with severe dyspnea /hypoxemia), effusions in ventilated patients and hemothorax. Drains inserted without any of these criteria were deemed potentially avoidable.FindingsA total of 288 procedures performed in 205 patients were reviewed: 249 (86.5%) drain insertions and 39 (13.5%) thoracenteses. Out of 249 chest drains, 113 (45.4%) were placed in the absence of drain insertion criteria and were deemed potentially avoidable. Of those, 33.6% were inserted for malignant effusions (without subsequent pleurodesis) and 34.5% for transudative effusions (median drainage duration of 2 and 4 days, respectively). Major complications were seen in 21.5% of all procedures. Pneumothorax requiring intervention (2.1%), bleeding (0.7%) and organ puncture or drain misplacement (2%) only occurred with drain insertion. Narcotics were prescribed more frequently following drain insertion vs. thoracentesis (27.1% vs. 9.1%, p = 0.03).Originality/valueRoutine use of chest drains for pleural effusions leads to avoidable drain insertions in a large proportion of cases and causes unnecessary harms.

Intrapleural Fibrinolytics and Deoxyribonuclease for Treatment of Indwelling Pleural Catheter-Related Pleural Infection: A Multi-Center Observational Study

<b><i>Background:</i></b> Indwelling pleural catheters (IPC) are increasingly used for management of recurrent (especially malignant) effusions. Pleural infection associated with IPC use remains a concern. Intrapleural therapy with tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) significantly reduces surgical referrals in non-IPC pleural infection, but data on its use in IPC-related pleural infection are scarce. <b><i>Objective:</i></b> To assess the safety and efficacy of intrapleural tPA and DNase in IPC-related pleural infection. <b><i>Methods:</i></b> Patients with IPC-related pleural infection who received intrapleural tPA/DNase in five Australian and UK centers were identified from prospective databases. Outcomes on <i>feasibility</i> of intrapleural tPA/DNase delivery, its <i>efficacy</i> and <i>safety</i> were recorded. <b><i>Results:</i></b> Thirty-nine IPC-related pleural infections (predominantly <i>Staphylococcus aureus</i> and gram-negative organisms) were treated in 38 patients; 87% had malignant effusions. In total, 195 doses (median 6 [IQR = 3–6]/patient) of tPA (2.5 mg–10 mg) and DNase (5 mg) were instilled. Most (94%) doses were delivered via IPCs using local protocols for non-IPC pleural infections. The mean volume of pleural fluid drained during the first 72 h of treatment was 3,073 (SD = 1,685) mL. Most (82%) patients were successfully treated and survived to hospital discharge without surgery; 7 required additional chest tubes or therapeutic aspiration. Three patients required thoracoscopic surgery. Pleurodesis developed post-infection in 23/32 of successfully treated patients. No major morbidity/mortality was associated with tPA/DNase. Four patients received blood transfusions; none had systemic or significant pleural bleeding. <b><i>Conclusion:</i></b> Treatment of IPC-related pleural infection with intrapleural tPA/DNase instillations via the IPC appears feasible and safe, usually without additional drainage procedures or surgery. Pleurodesis post-infection is common.

Evaluation of malignant effusions using MR-based T1 mapping

Our aim was to investigate the diagnostic yield of rapid T1-mapping for the differentiation of malignant and non-malignant effusions in an ex-vivo set up. T1-mapping was performed with a fast modified Look-Locker inversion-recovery (MOLLI) acquisition and a combined turbo spin-echo and inversion-recovery sequence (TMIX) as reference. A total of 13 titrated albumin-solutions as well as 48 samples (29 ascites/pleural effusions from patients with malignancy; 19 from patients without malignancy) were examined. Samples were classified as malignant-positive histology, malignant-negative histology and non-malignant negative histology. In phantom analysis both mapping techniques correlated with albumin-content (MOLLI: r = − 0.97, TMIX: r = − 0.98). MOLLI T1 relaxation times were shorter in malignancy-positive histology fluids (2237 ± 137 ms) than in malignancy-negative histology fluids (2423 ± 357 ms) as well as than in non-malignant-negative histology fluids (2651 ± 139 ms); post hoc test for all intergroup comparisons: < 0.05. ROC analysis for differentiation between malignant and non-malignant effusions (malignant positive histology vs. all other) showed an (AUC) of 0.89 (95% CI 0.77–0.96). T1 mapping allows for non-invasive differentiation of malignant and non-malignant effusions in an ex-vivo set up.