Analysis of invasive diagnostic techniques for pathological confirmation of pleural mesothelioma

BACKGROUND AND OBJECTIVES

Mesothelioma is an infrequent neoplasm with a poor prognosis that is related to exposure to asbestos and whose peak incidence in Europe is estimated from 2020. Its diagnosis is complex; imaging techniques and the performance of invasive pleural techniques being essential for pathological confirmation. The different diagnostic yields of these invasive techniques are collected in the medical literature. The present work consisted of reviewing how the definitive diagnosis of mesothelioma cases in our centre was reached to check if there was concordance with the data in the bibliography.

MATERIALS AND METHODS

Retrospective review of patients with a diagnosis of pleural mesothelioma in the period 2019-2021, analysing demographic data and exposure to asbestos, the semiology of the radiological findings and the invasive techniques performed to reach the diagnosis.

RESULTS

Twenty-six mesothelioma cases were reviewed. 22 men and 4 women. Median age 74 years. 9 patients had a history of asbestos exposure. Moderate-severe pleural effusion was the most frequent radiological finding (23/26). The sensitivity of the invasive techniques was as follows: Cytology 13%, biopsy without image guidance 11%, image-guided biopsy 93%, surgical biopsy 67%.

CONCLUSIONS

In our review, pleural biopsy performed with image guidance was the test that had the highest diagnostic yield, so it should be considered as the initial invasive test for the study of mesothelioma.

PET-CT-guided versus CT-guided biopsy in suspected malignant pleural thickening: a randomised trial

BACKGROUND

Pleural biopsy is the gold standard for diagnosis of pleural malignancy but a significant proportion will have an inconclusive biopsy despite ongoing clinical suspicion of malignancy. We investigated whether positron emission tomography-computed tomography (PET-CT) targeted pleural biopsy is superior to standard CT-guided pleural biopsy following an initial non-diagnostic biopsy.

METHODS

The TARGET trial was a multicentre, parallel group randomised trial. Patients with a previous inconclusive pleural biopsy but an ongoing suspicion of pleural malignancy were randomised (1:1) to receive either CT-guided biopsy (standard care) or PET-CT followed by a targeted CT biopsy (intervention). The primary outcome was pleural malignancy correctly identified from the trial biopsy.

RESULTS

Between September 2015 and September 2018, 59 participants were randomised from eight UK hospital sites: 29 to CT-only followed by targeted biopsy and 30 to PET-CT followed by targeted biopsy. The proportion of pleural malignancy correctly identified was similar between the groups (risk ratio 1.03 (95% CI 0.83-1.29); p=0.77). The sensitivity of the trial biopsy to identify pleural malignancy was 79% (95% CI 54-94%) in the CT-only group versus 81% (95% CI 54-96%) in the PET-CT group.

CONCLUSIONS

The results do not support the practice of PET-CT to guide pleural biopsies in patients with a previous non-diagnostic biopsy. The diagnostic sensitivity in the CT-only group was higher than anticipated and supports the practice of repeating a CT-guided biopsy following an inconclusive result if clinical suspicion of malignancy persists.

An overview on multimodal imaging for the diagnostic workup of pleural mesothelioma

Pleural mesothelioma (PM) is an aggressive disease that has a strong causal relationship with asbestos exposure and represents a major challenge from both a diagnostic and therapeutic viewpoint. Despite recent improvements in patient care, PM typically carries a poor outcome, especially in advanced stages. Therefore, a timely and effective diagnosis taking advantage of currently available imaging techniques is essential to perform an accurate staging and dictate the most appropriate treatment strategy. Our aim is to provide a brief, but exhaustive and up-to-date overview of the role of multimodal medical imaging in the management of PM.

Malignant Pleural Mesothelioma: Staging and Radiological Response Criteria in Patients Treated with Immune Checkpoint Inhibitors

Malignant pleural mesothelioma (MPM) is a rare and challenging cancer associated with asbestos fiber exposure, which offers limited treatment options. Historically, platinum-based chemotherapy has been the primary approach, but recent developments have introduced immunotherapy as a promising alternative for the treatment of this disease. Nevertheless, the unique growth patterns and occasionally ambiguous progressive characteristics of MPM make the interpretation of radiological assessments complex. Immunotherapy further complicates matters by introducing unconventional treatment response patterns such as hyperprogression and pseudoprogression. Consequently, there is a growing imperative to integrate the standard RECIST criteria with the mesothelioma-specific mRECIST criteria (version 1.1), as outlined in iRECIST. This comprehensive review is driven by the intent to provide a valuable resource for radiologists and clinicians engaged in the diagnosis, treatment, and monitoring of MPM in the era of immunotherapy. Specifically, the current imaging methods employed for staging and follow-up will be exposed and discussed, with a focus on the technical specificities and the mRECIST 1.1 methodology. Furthermore, we will provide a discussion about major clinical trials related to the use of immunotherapy in MPM patients. Finally, the latest advancements in radiomics, the applications of artificial intelligence in MPM, and their potential impact on clinical practice for prognosis and therapy, are discussed.

Pleural lymphoma combined with pleural sarcoidosis

A patient with sarcoidosis was found to have a massive left pleural effusion. Her chest computed tomography showed small nodules in the lung parenchyma and swelling of the hilar lymph nodes, with normal visceral and parietal pleura. Thoracoscopy showed white nodules on the visceral pleura and normal parietal pleura, which were resected. Epithelioid granulomas were seen in the visceral pleura and lung parenchyma. Surprisingly, in the parietal pleura, abnormal cells that were positive for the leukocyte common antigen, CD20, and CD79a were found, leading to the diagnosis of malignant B-cell lymphoma.

Determining the clinical utility of a breath test for screening an asbestos-exposed population for pleural mesothelioma: baseline results

Pleural mesothelioma (PM) is an aggressive cancer of the serosal lining of the thoracic cavity, predominantly caused by asbestos exposure. Due to nonspecific symptoms, PM is characterized by an advanced-stage diagnosis, resulting in a dismal prognosis. However, early diagnosis improves patient outcome. Currently, no diagnostic biomarkers or screening tools are available. Therefore, exhaled breath was explored as this can easily be obtained and contains volatile organic compounds, which are considered biomarkers for multiple (patho)physiological processes. A breath test, which differentiates asbestos-exposed (AEx) individuals from PM patients with 87% accuracy, was developed. However, before being implemented as a screening tool, the clinical utility of the test must be determined. Occupational AEx individuals underwent annual breath tests using multicapillary column/ion mobility spectrometry. A baseline breath test was taken and their individual risk of PM was estimated. PM patients were included as controls. In total, 112 AEx individuals and six PM patients were included in the first of four screening rounds. All six PM patients were correctly classified as having mesothelioma (100% sensitivity) and out of 112 AEx individuals 78 were classified by the breath-based model as PM patients (30% specificity). Given the large false positive outcome, the breath test will be repeated annually for three more consecutive years to adhere to the 'test, re-test' principle and improve the false positivity rate. A low-dose computed tomography scan in those with two consecutive positive tests will correlate test positives with radiological findings and the possible growth of a pleural tumor. Finally, the evaluation of the clinical value of a breath-based prediction model may lead to the initiation of a screening program for early detection of PM in Aex individuals, which is currently lacking. This clinical study received approval from the Antwerp University Hospital Ethics Committee (B300201837007).

Imaging of Malignant Pleural, Pericardial, and Peritoneal Mesothelioma

Malignant mesothelioma is a rare tumor arising from the mesothelial cells that line the pleura, pericardium, peritoneum, and tunica vaginalis. Imaging plays a primary role in the diagnosis, staging, and management of malignant mesothelioma. Multimodality imaging, including radiography, computed tomography (CT), magnetic resonance imaging (MRI), and F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), is used in a variety of scenarios, including diagnosis, guidance for tissue sampling, staging, and reassessment of disease after therapy. CT is the primary imaging modality used in staging. MRI has superior contrast resolution compared with CT and can add value in terms of determining surgical resectability in equivocal cases. MRI can further assess the degree of local invasion, particularly into the mediastinum, chest wall, and diaphragm, for malignant pleural and pericardial mesotheliomas. FDG PET/CT plays a role in the diagnosis and staging of malignant pleural mesothelioma (MPM) and has been shown to be more accurate than CT, MRI, and PET alone in the staging of malignant pleural mesothelioma. PET/CT can also be used to target lesions for biopsy and to assess prognosis, treatment response, and tumor recurrence.

Fully automated volumetric measurement of malignant pleural mesothelioma by deep learning AI: validation and comparison with modified RECIST response criteria

BACKGROUND

In malignant pleural mesothelioma (MPM), complex tumour morphology results in inconsistent radiological response assessment. Promising volumetric methods require automation to be practical. We developed a fully automated Convolutional Neural Network (CNN) for this purpose, performed blinded validation and compared CNN and human response classification and survival prediction in patients treated with chemotherapy.

METHODS

In a multicentre retrospective cohort study; 183 CT datasets were split into training and internal validation (123 datasets (80 fully annotated); 108 patients; 1 centre) and external validation (60 datasets (all fully annotated); 30 patients; 3 centres). Detailed manual annotations were used to train the CNN, which used two-dimensional U-Net architecture. CNN performance was evaluated using correlation, Bland-Altman and Dice agreement. Volumetric response/progression were defined as ≤30%/≥20% change and compared with modified Response Evaluation Criteria In Solid Tumours (mRECIST) by Cohen's kappa. Survival was assessed using Kaplan-Meier methodology.

RESULTS

Human and artificial intelligence (AI) volumes were strongly correlated (validation set r=0.851, p<0.0001). Agreement was strong (validation set mean bias +31 cm3 (p=0.182), 95% limits 345 to +407 cm3). Infrequent AI segmentation errors (4/60 validation cases) were associated with fissural tumour, contralateral pleural thickening and adjacent atelectasis. Human and AI volumetric responses agreed in 20/30 (67%) validation cases κ=0.439 (0.178 to 0.700). AI and mRECIST agreed in 16/30 (55%) validation cases κ=0.284 (0.026 to 0.543). Higher baseline tumour volume was associated with shorter survival.

CONCLUSION

We have developed and validated the first fully automated CNN for volumetric MPM segmentation. CNN performance may be further improved by enriching future training sets with morphologically challenging features. Volumetric response thresholds require further calibration in future studies.

Primary pleural liposarcoma: a rare differential for an opaque hemithorax

Primary pleural liposarcoma (PPL) is a rare primary malignant pleural tumour originating from primitive mesenchymal tissue. We report the case of a 25-year-old man with a 6-week history of shortness of breath, cough, chest pain and hoarseness of voice. Chest X-ray showed a left opacified hemithorax, and thoracic CT scan revealed a large, heterogeneous, hypodense mass in the left hemithorax. The patient was taken up for ultrasound-guided core biopsy of the mass lesion, and histopathological examination revealed the diagnosis as a pleomorphic variant of PPL. We highlight the importance of considering PPL as a differential diagnosis in cases of large hemithoracic masses.

[Giant Solitary Fibrous Tumour of the Pleura Compressing the Left Ventricle:Report of a Case]

A 71-year-old woman with chest pain and exertional dyspnea was referred to our hospital. Computed tomography revealed a huge intrathoracic tumor with left parietal pleural dissemination. Transthoracic echocardiography showed the left ventricular dysfunction due to external compression by the tumor. After excision of the tumor, marked improvement of the left ventricular dysfunction was obtained for eight years. But the patient died due to cardiac invasion of the tumor 9th year after surgery.

Primary pleural epithelioid hemangioendothelioma: case report and review of the literature

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular sarcoma with an unpredictable clinical behavior. Pleural EHEs have been associated with poor response to treatment and reduced survival. To date, no standard treatment for EHE is available. Here we report the case of a 53-year-old man who underwent radical surgery for a symptomatic primary pleural EHE. Clinical presentation was characterized by chronic pain in the left hemithorax with transitory flare, anemia, weight loss and progressive worsening of clinical conditions. After surgery, he resumed active life and normal daily activities and, at 8 months, 18F-FDG PET and computed tomography scan showed no radiological evidence of recurrent disease. Clinical signs of this rare disease, histological features, imaging findings and functional imaging are discussed. We also report a summary of other cases with resected pleural EHE and we briefly review the role of chemotherapeutic, immunomodulatory and antiangiogenic drugs for advanced disease.

Conspicuity of malignant pleural mesothelioma in contrast enhanced MDCT - arterial phase or late phase?

BACKGROUND

To determine if late phase is superior to arterial phase intraindividually regarding conspicuity of MPM in contrast enhanced chest MDCT.

METHODS

28 patients with MPM were included in this retrospective study. For all patients, chest CT in standard arterial phase (scan delay ca. 35 s) and abdominal CT in portal venous phase (scan delay ca. 70 s) was performed. First, subjective analysis of tumor conspicuity was done independently by two radiologists. Second, objective analysis was done by measuring Hounsfield units (HU) in tumor lesions and in the surrounding tissue in identical locations in both phases. Differences of absolute HUs in tumor lesions between phases and differences of contrast (HU in lesion - HU in surrounding tissue) between phases were determined. HU measurements were compared using paired t-test for related samples. Potential confounding effects by different technical and epidemiological parameters between phases were evaluated performing a multiple regression analysis.

RESULTS

Subjective analysis: In all 28 patients and for both readers conspicuity of MPM was better on late phase compared to arterial phase. Objective analysis: MPM showed a significantly higher absolute HU in late phase (75.4 vs 56.7 HU, p < 0.001). Contrast to surrounding tissue was also significantly higher in late phase (difference of contrast between phases 18.5 HU, SD 10.6 HU, p < 0.001). Multiple regression analysis revealed contrast phase and tube voltage to be the only significant independent predictors for tumor contrast.

CONCLUSIONS

In contrast enhanced chest-MDCT for MPM late phase scanning seems to provide better conspicuity and higher contrast to surrounding tissue compared to standard arterial phase scans.

Primary pleural epithelioid angiosarcoma treated successfully with anti-PD-1 therapy: A rare case report

RATIONALE

Primary pleural angiosarcoma (PPA) is an extremely rare malignancy for which there is no consensus on treatment. The clinical course of PPA is usually quickly fatal, regardless of the treatment used.

PATIENT CONCERNS

We describe the rare case of a 52-year-old man who presented initially with hemoptysis and received emergency surgery for the primary.

DIAGNOSES

He received a confirmed diagnosis of primary pleural angiosarcoma (PPA) by postoperative pathology and was subsequently treated with radiotherapy and chemotherapy, but had failed and was intolerant to chemotherapy.

INTERVENTIONS

The patient had 5% tumor PD-L1 positivity with 22C3 pharmDx and received pembrolizumab (200 mg every 21 days) for 13 cycles.

OUTCOMES

The disease remained well controlled according to the RECIST 1.1. criteria. He is currently under observation and waiting to start the next cycle of immunotherapy.

LESSON

Our case report suggests that the use of anti-PD-1 therapy does show efficacy in the treatment of PPA and may provide a viable treatment option for patients.

Primary Leiomyoma of the Visceral Pleura: An Unexpected Occurrence

BACKGROUND/AIM

Leiomyoma is a rare benign tumor originating from smooth muscle fibres. In the respiratory tract, these tumors are rare and in the pleura, cases are exceptional, with only a few reported so far. This is the main reason we decided to present this case of primary leiomyoma of the visceral pleura.

CASE REPORT

We present a case of a 51-year-old asymptomatic patient who, during a routine medical examination using standard chest radiography, presented with a 3 by 2 cm homogenous mass in the right superior pulmonary area, tangent to the chest wall (same level with the 3rd rib). Further investigation using computed tomography (CT) in the chest confirmed the presence of a 31/18 mm solid mass in the right upper lobe, in contact with the parietal pleura. Surgery was performed for two reasons: i) removal of the tumoral mass and ii) establishing a histopathological diagnosis. Intraoperatively, a well-defined, homogenous, ivory white non-infiltrating mass was discovered in the right upper lobe on the visceral pleura and in close proximity to the minor fissure. The mass was removed with negative surgical margins and was left with healthy tissue. Histopathological examination and immunohistochemistry came as a surprise, establishing our diagnosis of leiomyoma.

CONCLUSION

Primitive pleural leiomyoma must remain a possibility when considering the differential diagnosis of pleural tumors. The main course of treatment is complete surgical resection. In our case, long-term follow up did not present any local recurrence.

Diffusion-weighted imaging diagnostic algorithm in patients with suspected pleural malignancy

Objectives

The purpose of this study was to analyze the diagnostic performance and clinical application of diffusion-weighted imaging (DWI) in patients with suspected pleural malignancy (PM).

Methods

A retrospective review of patients with suspected PM was performed from March 2014 to August 2018 (NCT 02320617). All patients underwent chest DWI and computed tomography (CT) with cytological or histopathological findings as reference standards. The diagnostic performance of DWI and CT was analyzed and compared. A DWI diagnostic algorithm with three sequential steps was established.

Results

Seventy patients (61.6 ± 13.6 years; 47 males and 23 females) were included. The sensitivity of DWI (94.2%, 49/52) for the diagnosis of PM was significantly higher compared with CT (67.3%, 35/52), with similar specificity (72.2% vs. 72.2%, respectively). The apparent diffusion coefficient of malignant lesions (1.15 ± 0.32 × 10⁻³ mm²/s) was lower compared with benign lesions (1.46 ± 0.68 × 10⁻³ mm²/s), but the cutoff value was difficult to define for overlap between groups. Approximately 62.5% (5/8) of invasive procedures were avoided when using the DWI diagnostic algorithm in patients with suspected PM without N3 lymph node or extra-thoracic metastasis.

Conclusion

Including DWI into the diagnostic algorithm of suspected PM can effectively identify malignancy and avoid unnecessary invasive procedures, which may have some potential in clinical application.

Key Points

• Diffusion-weighted imaging can identify pleural malignancy much more efficiently than CT.

• A diffusion-weighted imaging diagnostic algorithm helped to avoid unnecessary invasive procedures in patients without N3 lymph node or extra-thoracic lesions.

• A hyperintense signal on DWI at a high b value (800 s/mm²) but not at a low b value (50 s/mm²) was a reliable signature of PM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08013-6.

[Malignant Pleural Mesothelioma with High Serum Granulocyte Coronary Stimulating Factor]

A 38-year-old man was admitted to our hospital because of right chest pain and high fever. Chest X-ray and computed tomography scan revealed right pleural effusion and pleural thickness. Diagnosis of malignant mesothelioma was established by pleural biopsy. Serum level of granulocyte colony stimulating factor (G-CSF) was high. We performed extrapleural pneumonectomy which improved high fever and inflammation, however the patient died three months after surgery.

A Model for Predicting Malignant Sub-pleural Solid Masses Using Grayscale Ultrasound and Ultrasound Elastography

This article aimed to establish a prediction model of grayscale sonography and ultrasound elastography for malignant sub-pleural solid masses and evaluate its diagnostic value. The study included 153 patients, including 89 patients with malignant tumors and 64 patients with benign diseases. Statistical differences between the malignant and benign groups were found in the factors of age, air bronchogram, borderline, shape and elasticity score (p < 0.05). Age, elasticity score and borderline were effective factors for predicting malignant sub-pleural solid masses, offering an area under the receiver operating characteristic curve (AUROC) value of 0.72 (95% confidence interval [CI] 0.64-0.80), 0.73 (95% CI 0.65-0.79) and 0.70 (95% CI 0.62-0.77), respectively. The AUROC value of the prediction model for malignant sub-pleural solid masses was 0.88 (95% CI 0.81-0.92), which indicates that the prediction model was able to improve the diagnostic accuracy and that it may prove a useful auxiliary diagnostic tool for malignant sub-pleural solid masses, especially in primary health care institutions in developing countries.

FDG PET/CT of an Advanced Case of Malignant Nerve Sheath Tumor of Pleura

ABSTRACT

We present a rare case of malignant nerve sheath tumor of pleura referred for the evaluation of metastases and local invasion. FDG PET/CT demonstrated a hypermetabolic tumoral lesion extensively involving the right pleura with no involvement of mediastinal structures or pulmonary parenchyma and no clear evidence of distant metastasis. Malignant nerve sheath tumor of pleura is an extremely rare entity, and FDG PET/CT is valuable in demonstrating the extent of disease and can have potential role for postsurgical as well as postchemotherapy assessment of possible residual disease.

A comparison between MRI and CT in the assessment of primary tumour volume in mesothelioma

INTRODUCTION

Primary tumour staging in Malignant Pleural Mesothelioma (MPM) using Computed Tomography (CT) imaging is confounded by perception errors reflecting low spatial resolution between tumour and adjacent structures. Augmentation using perfusion CT is constrained by radiation dosage. In this study, we evaluated an alternative tumour staging method using perfusion-tuned Magnetic Resonance Imaging (MRI).

METHODS

Consecutive patients with suspected MPM were recruited to a prospective observational study. All had MRI (T1-weighted, isotropic, contrast-enhanced 3-Tesla perfusion imaging) and CT (contrast-enhanced) pre-biopsy. Patients diagnosed with MPM underwent MRI and CT volumetry, with readers blinded to clinical data. MRI volumetry was semi-automated, using signal intensity limits from perfusion studies to grow tumour regions within a pleural volume. A similar CT method was not possible, therefore all visible tumour was manually segmented. MRI and CT volumes were compared (agreement, correlation, analysis time, reproducibility) and associations with survival examined using Cox regression.

RESULTS

58 patients were recruited and had MRI before biopsy. 31/58 were diagnosed with MPM and these scans were used for volumetry. Mean (SD) MRI and CT volumes were 370 cm3 and 302 cm3, respectively. MRI volumes were larger (average bias 61.9 cm3 (SD 116), 95 % limits (-165.5 - 289 cm3), moderately correlated with CT (r = 0.56, p = 0.002) and independently associated with survival (HR 4.03 (95 % CI 1.5-11.55), p = 0.006). CT volumes were not associated with survival, took longer to compute than MRI volumes (mean (SD) 151 (19) v 14 (2) minutes, p=<0.0001) and were less reproducible (inter-observer ICC 0.72 for CT, 0.96 for MRI).

CONCLUSIONS

MRI and CT generate different tumour volumes in MPM. In this study, MRI volumes were larger and were independently associated with survival. MRI volumetry was quicker and more reproducible than CT.

Giant Pleural Tumor And Severe Hypoglycemia: Doege-Potter Syndrome In A Previously Healthy Female

AIntroduction: Doege-Potter's syndrome is a rare paraneoplastic syndrome, consisting in hypoglycemia and solitary fibrous tumor of the pleura. These tumors represent < 5% of all pleural tumours and can only be cured by surgery. In this article, we report a case of a patient presenting with severe hypoglycemia, as the only symptom, and a mass occupying the entire left hemithorax. Case presentation: A54 year old female with severe hypoglycemia, a chest radiography with almost total opacification of the left hemithorax and a computed tomography scan with a mass in the left hemithorax. Surgery was performed and a mass with 30cm × 18cm × 11cm weighing 3195g was resected. The postoperative course was uneventful with immediate resolution of the hypoglycemia. The immunohistochemistry diagnosis was solitary fibrous tumor of the pleura. Conclusions: Solitary fibrous tumor of the pleura are very rare. Less than 5% are associated with hypoglycemia, taking the form of Doege-Potter Syndrome. Radiation therapy and chemotherapy have shown low response rate and complete surgical resection is the only procedure that offers cure. This case reports describes a rare giant solitary fibrous tumor of the pleura with severe hypoglycemia, successfully treated by surgery. Long-term follow-up of the patient after the surgery is necessary for detection of any possible recurrence.

[Malignant Melanoma of Pleura: A Case Report and Literature Review]

Malignant melanoma is a kind of tumor produced by human melanocytes. It has a high degree of malignancy, early metastasis and high mortality. Most melanomas are caused by malignant skin nevus and can also be seen in the digestive tract such as rectum and anus. Primary malignant melanoma of pleura is rare, rarely seen in case reports. This paper reports the clinical data of a case of malignant melanoma with cough, expectoration and pleural effusion as the first symptoms diagnosed by thoracoscopy combined with pathology in Beijing Friendship Hospital Affiliated to Capital Medical University, and analyzes and summarizes the literature data.

Prognostic value of SUVmax on 18F-fluorodeoxyglucose PET/CT scan in patients with malignant pleural mesothelioma

Introduction

The maximum standardized uptake value (SUVmax) in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) may be of prognostic significance for patients with malignant pleural mesothelioma (MPM). This retrospective study aimed to investigate the prognostic value of the SUVmax in patients with MPM.

Materials and methods

Medical records were retrospectively reviewed for the patients who were diagnosed with histopathologically proven MPM between 2009 and 2018 at Samsung Medical Center. For each patient, SUVmax was calculated for the primary lesion on PET/CT. To determine optimal cutoff values for predicting mortality, receiver operating characteristic curves were used.

Results

Among the 54 study patients, 34 (63.0%) had epithelioid subtype, 13 (24.1%) had sarcomatoid or biphasic subtype, and 7 (13.0%) had mesothelioma, not otherwise specified (NOS). The median overall survival (OS) was 8.7 months, and the median SUVmax was 9.9. The median values of SUVmax were 5.5 in patients with epithelioid subtype, 11.7 in those with sarcomatoid/biphasic subtype, and 13.3 in those with NOS subtype (P = 0.003). The optimal cutoff values of SUVmax to predict mortality were 10.1 in all patients, and 8.5 in patients with epithelioid subtype. In multivariate analysis, SUVmax was significantly associated with overall survival in all patients (P = 0.003) and in patients with epithelioid subtype (P = 0.012), but not in those with non-epithelioid subtype.

Conclusions

SUVmax in PET/CT is an independent prognostic factor in patients with MPM, especially those with epithelioid subtype. The histologic subtype of MPM should be considered when evaluating the prognostic significance of SUVmax.

Thoracic solitary fibrous tumors: an analysis of 70 patients who underwent surgical resection in a single institution

BACKGROUND

Thoracic solitary fibrous tumors (TSFTs) are uncommon mesenchymal tumors. The data regarding surgical outcomes and prognostic factors are scarce. This retrospective paper is to analyze surgical outcomes, clinical characteristics and prognosis of TSFT.

METHODS

A single-center retrospective study of the data of 70 patients with TSFT who underwent surgical resection in our department between August 2008 and October 2014 was conducted.

RESULTS

A total of 70 TSFTs (58 benign, 12 malignant) were included and all patients underwent complete surgical resection except one recurrent patient with initial treatment. TSFTs originated from the pleura (n = 43), lung (n = 9), mediastinum (n = 16), esophagus (n = 1) and diaphragm (n = 1), respectively. Mass excision was only performed in 29 patients, en bloc excision including surrounding structures was performed in 41 patients. During follow-up, no tumor recurrence occurred in benign TSFT patients. All recurrences occurred in 6 malignant patients, and 5 of them died because of local recurrence and distant metastasis. Median follow-up was 95 months (range, 3-133 months). The 5-year overall survival (OS) of TSFT patients was 94.3%. The 5-year relapse-free survival and OS of malignant TSFT patients were 58.3% and 66.7%, respectively.

CONCLUSION

The gold standard of TSFT treatment is complete surgical resection. VATS is safe and reliable for treating selected TSFT patients. Aggressive surgical resection could be underwent in such patients of local recurrence or solitary metastatic tumor. A long-term follow-up is necessary due to the risk of recurrence.

Localized malignant mesothelioma, an unusual and poorly characterized neoplasm of serosal origin: best current evidence from the literature and the International Mesothelioma Panel

Localized malignant mesotheliomas (LMM) is an uncommon and poorly recognized neoplasm. Its pathologic diagnosis is often surprising in patients with serosal/subserosal based localized tumors that are clinically suspicious for metastatic lesions or primary sarcomas. Once a tumor is diagnosed as "mesothelioma", LMM is often mistaken for diffuse malignant mesothelioma (DMM). Best currently available evidence about LMM was collected from the literature and cases diagnosed by members of the International Mesothelioma Panel (IMP). One hundred and one (101) LMM have been reported in the English literature. Patients had localized tumors with identical histopathologic features to DMM. Patients ranged in age from 6 to 82 years; 75% were men. Most (82%) of the tumors were intrathoracic. Others presented as intrahepatic, mesenteric, gastric, pancreatic, umbilical, splenic, and abdominal wall lesions. Tumors varied in size from 0.6 to 15 cm. Most patients underwent surgical resection and/or chemotherapy or radiation therapy. Median survival in a subset of patients was 29 months. Seventy two additional LMM from IMP institutions ranged in age from 28 to 95 years; 58.3% were men. Sixty tumors (83.3%) were intrathoracic, others presented in intraabdominal sites. Tumors varied in size from 1.2 to 19 cm. Median survival for 51 cases was 134 months. Best evidence was used to formulate guidelines for the diagnosis of LMM. It is important to distinguish LMM from DMM as their treatment and prognosis is different. A multidisciplinary approach is needed for the diagnosis of LMM as it shows identical histopathology and immunophenotype to DMM.

Contact of a tumour with the pleura is not associated with regional recurrence following stereotactic ablative radiotherapy for early stage non-small cell lung cancer

BACKGROUND AND PURPOSE

The aim was to investigate the incidence of isolated regional failure following stereotactic ablative radiotherapy (SABR) and risk factors for recurrence.

MATERIALS AND METHODS

Early stage non-small cell lung cancer (NSCLC) patients treated with SABR were included in this retrospective cohort study, with isolated regional recurrence (IRR) as primary endpoint, distant recurrence (DR) and overall survival (OS) as secondary endpoints. Survival analyses were performed using the cumulative incidence function (IRR and DR) or the Kaplan-Meier method (OS) and Cox proportional hazards modelling for univariate and multivariate analyses. The prognostic effect of contact between the tumour and the pleura was investigated using the CT scans used for SABR planning.

RESULTS

A total of 554 patients were included, of whom 494 could be analysed for IRR. The median follow-up for surviving patients was 48.1 months. Twenty-one patients developed an IRR (4%). The cumulative incidence of IRR and DR after 1-, 2-, and 5 years was 2%, 3%, 7% and 8%, 15% and 21%, respectively. Two year OS was 71%. The presence and type of pleural contact was not associated with any of the studied outcomes.

CONCLUSION

The presence, type and length of pleural contact as surrogate for visceral pleural invasion were not predictive for outcome. Further studies focussing on risk factors for occult nodal involvement, (I)RR, distant metastases and mortality in early stage NSCLC are warranted for the development of risk adapted diagnostic, treatment and follow-up strategies as more younger, operable and fitter patients receive SABR.

Type II pleuropulmonary blastoma in a 2-year-old girl: a case report

Pleuropulmonary blastoma (PPB) is a very rare, malignant aggressive primary lung tumor, which occurs mainly in children less than 5 years old. Due to its poor prognosis, it is aggressively treated with multimodal therapy including surgery and chemotherapy. We present a case of PPB in a 2-year-old girl who was brought to the pediatric clinic for fever, cough and respiratory distress. Imaging studies showed a heterogeneous solid-cystic mass (12∕9∕11 cm) in the upper right pulmonary lobe. Through right thoracotomy, a specimen was obtained, the histopathological and immunohistochemical features of the specimen being suggestive for type II PPB. Aggressive chemotherapy and right pneumonectomy resulted in control of disease, the patient being currently in complete remission four years after the diagnosis.

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.

Presentation of Malignant Pleural Mesothelioma with Symptomatic Brain Metastasis: Report of a Case

Central nervous system metastases from diffuse malignant pleural mesothelioma are rare. Here we describe a patient without known asbestos exposure who presented with chest pain, increasing shortness of breath and persistent headache. Evaluation found biphasic malignant mesothelioma of the right hemithorax and a single brain metastasis confirmed by computed tomography. This represents only the second case of a patient with pleural mesothelioma presenting with symptomatic central nervous system metastases.

Computer-assisted Diagnosis for Early Stage Pleural Mesothelioma

Objectives: Pleural thickenings as biomarker of exposure to asbestos may evolve into malignant pleural mesothelioma. Foritsearly stage, pleurectomy with perioperative treatment can reduce morbidity and mortality. The diagnosis is based on a visual investigation of CT images, which is a time-consuming and subjective procedure. Our aim is to develop an automatic image processing approach to detect and quantitatively assess pleural thickenings.

Methods: We first segment the lung areas, and identify the pleural contours. A convexity model is then used together with a Hounsfield unit threshold to detect pleural thickenings. The assessment of the detected pleural thickenings is based on a spline-based model of the healthy pleura.

Results: Tests were carried out on 14 data sets from three patients. In all cases, pleural contours were reliably identified, and pleural thickenings detected. PC-based Computation times were 85 min for a data set of 716 slices, 35 min for 401 slices, and 4 min for 75 slices, resulting in an average computation time of about 5.2 s per slice. Visualizations of pleurae and detected thickeningswere provided.

Conclusion: Results obtained so far indicate that our approach is able to assist physicians in the tedious task of finding and quantifying pleural thickenings in CT data. In the next step, our system will undergo an evaluation in a clinical test setting using routine CT data to quantifyits performance.

CT diagnosis and differentiation of benign and malignant varieties of solitary fibrous tumor of the pleura

To investigate computed tomography (CT) characteristics of benign and malignant solitary fibrous tumors of the pleura (SFTPs).Preoperative CTs for 60 SFTP cases (49 benign and 11 malignant) with subsequently confirmed diagnoses were retrospectively analyzed.Tumor morphologies included mounded or mushroom umbrella-shape (19 cases, 31.7%), quasi-circular or oval-shape (30 cases, 50%), and growth resembling a casting mould (12 cases, 20%). Maximum tumor diameters were 1.1 to 18.9 cm (average: 6.4 ± 4.8 cm). Fifty-seven cases had clear boundaries, and 3 had partially coarse boundaries. Twenty-seven cases showed homogeneous density; 33, "geographic"-patterned inhomogeneous density; 6, calcifications; 12, intratumor blood vessels; and 3, thick nourishing peritumoral blood vessels. Pleural thickening (regular and irregular) was found adjacent to tumors in 4, compression of adjacent ribs with absorption and cortical sclerosis in 2, and location adjacent to ribs with bony destruction in 1. Four cases had a small amount of lung tissue enfolded along the boundary, 2 had multiple peritumoral pulmonary bullae, and 9 had small ipsilateral pleural effusions. Compared with benign and malignant SFTPs were larger (P < .001), had inhomogeneous density, and were more commonly associated with intratumor blood vessels and pleural effusions (P < .01).CT revealed characteristic patterns in SFTPs, including casting mould-like growth, rich blood supply, and "geographic"-patterned enhancement. In addition, larger tumor size, inhomogeneous intensities, abundant intratumor blood vessels, and pleural effusions were more common with malignancy. Lastly, multislice CT angiography can reveal feeding arteries and help guide surgical management.

Pleural effusion biomarkers and computed tomography findings in diagnosing malignant pleural mesothelioma: A retrospective study in a single center

In this study, we aimed to examine the clinical value of the pleural effusion (PE) biomarkers, soluble mesothelin-related peptide (SMRP), cytokeratin 19 fragment (CYFRA 21–1) and carcinoembryonic antigen (CEA), and the utility of combining chest computed tomography (CT) findings with these biomarkers, in diagnosing malignant pleural mesothelioma (MPM). We conducted a retrospective cohort study in a single center. Consecutive patients with undiagnosed pleural effusions who underwent PE analysis between September 2014 and August 2016 were reviewed. This study included 240 patients (32 with MPM and 208 non-MPM). SMRP and the CYFRA 21-1/CEA ratio had a sensitivity and specificity for diagnosing MPM of 56.3% and 86.5%, and 87.5% and 74.0%, respectively. Using receiver operating characteristics (ROC) curve analysis of the ability of these markers to distinguish MPM from all other PE causes, the area under the ROC curve (AUC) for SMRP and the CYFRA 21-1/CEA ratio was 0.804 and 0.874, respectively. The sensitivity and specificity of SMRP combined with the CYFRA 21-1/CEA ratio were 93.8% and 64.9%, respectively. The sensitivity of the combination of SMRP, the CYFRA 21-1/CEA ratio, and the presence of Leung’s criteria (a chest CT finding that is suggestive of malignant pleural disease) was 93.8%. In conclusion, the combined PE biomarkers had a high sensitivity for diagnosing MPM, although the addition of chest CT findings did not improve the sensitivity of SMRP combined with the CYFRA 21-1/CEA ratio. Combination of these biomarkers helped to rule out MPM effectively among patients at high risk of suffering MPM and would be valuable especially for old frail patients who have difficulty in undergoing invasive procedures such as thoracoscopy.

Pleural Alveolar Rhabdomyosarcoma

Alveolar rhabdomyosarcoma (ARMS) commonly occurring in children and adolescents, is a rare and aggressive soft tissue malignancy. Here, a rare case of pleural ARMS is reported in a boy presenting dyspnea for two weeks. The pathology of a biopsy specimen from pleura showed ARMS. PAX3-FKHR fusion protein is positive and the PAX7-FKHR fusion protein is negative as detected by fluorescence in situ hybridization. The prognosis of this patient was poor and nonresponsive to chemotherapy.

Can CT and MR Shape and Textural Features Differentiate Benign Versus Malignant Pleural Lesions?

RATIONALE AND OBJECTIVES

The study aimed to identify a radiomic approach based on CT and or magnetic resonance (MR) features (shape and texture) that may help differentiate benign versus malignant pleural lesions, and to assess if the radiomic model may improve confidence and accuracy of radiologists with different subspecialty backgrounds.

MATERIALS AND METHODS

Twenty-nine patients with pleural lesions studied on both contrast-enhanced CT and MR imaging were reviewed retrospectively. Three texture and three shape features were extracted. Combinations of features were used to generate logistic regression models using histopathology as outcome. Two thoracic and two abdominal radiologists evaluated their degree of confidence in malignancy. Diagnostic accuracy of radiologists was determined using contingency tables. Cohen's kappa coefficient was used to assess inter-reader agreement. Using optimal threshold criteria, sensitivity, specificity, and accuracy of each feature and combination of features were obtained and compared to the accuracy and confidence of radiologists.

RESULTS

The CT model that best discriminated malignant from benign lesions revealed an AUC_CT = 0.92 ± 0.05 (P < 0.0001). The most discriminative MR model showed an AUC_MR = 0.87 ± 0.09 (P < 0.0001). The CT model was compared to the diagnostic confidence of all radiologists and the model outperformed both abdominal radiologists (P < 0.002), whereas the top discriminative MR model outperformed one of the abdominal radiologists (P = 0.02). The most discriminative MR model was more accurate than one abdominal (P = 0.04) and one thoracic radiologist (P = 0.02).

CONCLUSION

Quantitative textural and shape analysis may help distinguish malignant from benign lesions. A radiomics-based approach may increase diagnostic confidence of abdominal radiologists on CT and MR and may potentially improve radiologists' accuracy in the assessment of pleural lesions characterized by MR.

Convex border of peripheral non-small cell lung cancer on CT images as a potential indicator of pleural invasion

The aim of the study is to evaluate the use of the tumor border in peripheral non-small cell lung cancer (NSCLC) as an indicator of pleural invasion.This retrospective study was performed at a single tertiary center. The analysis of 136 patients with peripheral NSCLC included 101 (74.3%) patients with pathologically proven pleural invasion and 35 (25.7%) patients without pleural invasion. The tumor borders on conventional computed tomography (CT) were classified into 5 types on lung window setting: type 1, S or reverse S border with a blunt angle; type 2, sharp angle; type 3, concave border with a blunt angle; type 4, straight border with a perpendicular angle; and type 5, convex border with a perpendicular or blunt angle. In patients with more than 1 tumor border type, the priority was type 5, 4, 3, 2, and 1. Blunt angle, pleural contact >3 cm, and adjacent pleural thickening were also recorded for comparison with pleural invasion of peripheral tumors.Tumor border types 2 and 5 significantly differed between patients with and without pleural invasion (P = .001 and P < .001, respectively). Patients with and without pleural invasion did not significantly differ in tumor border type 1, tumor border type 3, tumor border type 4, blunt angle, pleural contact >3 cm, or pleural thickening. Tumor border type 5 was a moderate indicator of pleural invasion with positive LR, 5.20; accuracy, 57%; sensitivity, 45%; specificity, 91%; PPV, 94%; and NPV, 36%. Tumor border type 2 was a weak indicator of pleural invasion with positive LR, 0.51; accuracy, 34%; sensitivity, 34%; specificity, 34%; PPV, 60%; and NPV, 15%.Tumor border type 5 has a high PPV and high specificity for predicting pleural invasion by peripheral NSCLC.

Breast liposarcoma with solitary metastasis to the pleura: A case report

RATIONALE

Breast cancer is the most prevalent malignancy in women worldwide. Our patient presented with a history of breast liposarcoma (LPS) and was found to have pleural metastasis during the initial workup.

PATIENT CONCERNS

The patient was complaining about chest pain and dyspnea that had persisted for a week.

DIAGNOSES

After a full evaluation and histological diagnosis, she was diagnosed as metastatic breast LPS.

INTERVENTIONS

We adopted 6 cycles of pegylated liposomal doxorubicin (PLD) plus ifosfamide as 1st-line palliative chemotherapy, combined with local pleural effusion management.

OUTCOMES

The patient's symptoms were notably relieved, and both malignant metastatic lesions and pleural effusion were controlled.

LESSONS

Although metastatic breast LPS is rarely reported and incurable, more clinical experience and use of next-generation sequencing should be helpful in finding the effective treatment for metastatic LPS.

[Solitary Fibrous Tumor Originating from the Visceral Pleura Presenting an Extrapleural Sign;Report of a Case]

We report a case of solitary fibrous tumor (SFT) originating from the visceral pleura, which presented an extrapleural sign on chest computed tomography (CT) and magnetic resonance imaging (MRI). A 44-year-old woman presented at our hospital for a growing mass visible in chest X-rays. Chest CT and MRI detected a 27×12 mm lesion on the intrathoracic side of the right 3rd intercostal space. The extrapleural signs strongly suggested the tumor to be chest wall origin. However, the tumor was found to be pedunculate with an umbrella-like appearance locating on the visceral pleura of the lung. Histopathological examination demonstrated SFT originating from the visceral pleura.

[Not Available]

Zusammenfassung. Infizierte und septierte Pleuraergüsse sind kompliziert. Ultraschall ist die beste Methode, Septierungen zu entdecken. Unzureichend behandelte parapneumonische Ergüsse haben ein hohes Risiko für lange Hospitalisation und erhöhte Mortalität bei insuffizienter Pleuradrainage. Pleurale Verdickungen sind vielgestaltig, diffus oder umschrieben, knotig und meist echoarm. Die meisten Patienten mit Pleuritis zeigen typische Veränderungen. In malignen Pleuraergüssen sind oft Metastasen zu entdecken. Die Rolle der Sonografie beim Mesotheliom ist in Diskussion.

[Schwannoma can be a rare cause of abdominal pain]

This case report describes a 43-year-old female with persisting abdominal pain. She was examined on several occasions, but no obvious reason for the pains was found. Due to recurring of the symptoms, a computed tomography was performed, and a tumour in the thoracic wall by the lower left region of the lung could be seen. Biopsy revealed a schwannoma, and an operation was conducted successfully. After radical resection, the patient's pains declined.

Large pleural tumor revealed by severe hypoglycemia: Doege-Potter syndrome

AIM

Doege-Potter syndrome is a rare condition consisting of a mesenchymal tumor, either benign or malignant, accompanied by severe hypoglycemia. The syndrome was first described independently by two American physicians, Karl Walter Doege (1867-1932) and Roy Pilling Potter (1879-1968), in 1930, but it was not before 1988 that it was associated with non-islet cell tumor production of insulin growth factor (IGF) that induces hypoglycemia as a paraneoplastic syndrome.

CASE PRESENTATION

We present the case of a 61-year-old woman with severe hypoglycemia that induced seizures. On the general check-up, a massive tumor occupying the lower part of left hemi-thorax was discovered. Initially, corticosteroids, glucose i.v. and high carbohydrate diet managed to prevent the severe blood glucose drop. Surgery exposed a massive well-defined pleural tumor. After surgical removal, blood glucose stabilized. Histological examination confirmed the fibrous tumor that proved to be malignant on immunochemistry.

DISCUSSION

The authors discuss other cases reported in the literature of this rare condition and its pathogenic mechanisms, the presented case being the first reported in Romania.

CONCLUSIONS

The clinician should be aware of the possible existence of a pleural tumor in a patient presenting an unexplained hypoglycemia because the surgical removal of the tumor can solve the clinical manifestations.

The diagnostic performance of routinely acquired and reported computed tomography imaging in patients presenting with suspected pleural malignancy

OBJECTIVES

Contrast-enhanced computed tomography (CT) provides essential cross-sectional imaging data in patients with suspected pleural malignancy (PM). The performance of CT in routine practice may be lower than in previously reported research. We assessed this relative to 'real-life' factors including use of early arterial-phase contrast enhancement (by CT pulmonary angiography (CTPA)) and non-specialist radiology reporting.

MATERIALS AND METHODS

Routinely acquired and reported CT scans in patients recruited to the DIAPHRAGM study (a prospective, multi-centre observational study of mesothelioma biomarkers) between January 2014 and April 2016 were retrospectively reviewed. CT reports were classified as malignant if they included specific terms e.g. "suspicious of malignancy", "stage M1a" and benign if others were used e.g. "indeterminate", "no cause identified". All patients followed a standard diagnostic algorithm. The diagnostic performance of CT (overall and based on the above factors) was assessed using 2×2 Contingency Tables.

RESULTS

30/345 (9%) eligible patients were excluded (non-contrast (n=13) or non-contiguous CT (n=4), incomplete follow-up (n=13)). 195/315 (62%) patients studied had PM; 90% were cyto-histologically confirmed. 172/315 (55%) presented as an acute admission, of whom 31/172 (18%) had CTPA. Overall, CT sensitivity was 58% (95% CI 51-65%); specificity was 80% (95% CI 72-87%). Sensitivity of CTPA (performed in 31/315 (10%)) was lower (27% (95% CI 9-53%)) than venous-phase CT (61% (95% CI 53-68%) p=0.0056). Sensitivity of specialist thoracic radiologist reporting was higher (68% (95% CI 55-79%)) than non-specialist reporting (53% (95% CI 44-62%) p=0.0488). Specificity was not significantly different.

CONCLUSION

The diagnostic performance of CT in routine clinical practice is insufficient to exclude or confirm PM. A benign CT report should not dissuade pleural sampling where the presence of primary or secondary pleural malignancy would alter management. Sensitivity is lower with non-thoracic radiology reporting and particularly low using CTPA.

Percutaneous Cryoablation for the Treatment of Recurrent Malignant Pleural Mesothelioma: Safety, Early-Term Efficacy, and Predictors of Local Recurrence

PURPOSE

To determine safety and early-term efficacy of CT-guided cryoablation for treatment of recurrent mesothelioma and assess risk factors for local recurrence.

MATERIALS AND METHODS

During the period 2008-2012, 24 patients underwent 110 cryoablations for recurrent mesothelioma tumors in 89 sessions. Median patient age was 69 years (range, 48-82 y). Median tumor size was 30 mm (range, 9-113 mm). Complications were graded using Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4.0). Recurrence was diagnosed on CT or positron emission tomography/CT by increasing size, nodular enhancement, or hypermetabolic activity and analyzed using the Kaplan-Meier method. Cox proportional hazards model was used to determine covariates associated with local tumor recurrence.

RESULTS

Median duration of follow-up was 14.5 months. Complications occurred in 8 of 110 cryoablations (7.3%). All but 1 complication were graded CTCAE v4.0 1 or 2. No procedure-related deaths occurred. Freedom from local recurrence was observed in 100% of cases at 30 days, 92.5% at 6 months, 90.8% at 1 year, 87.3% at 2 years, and 73.7% at 3 years. Tumor recurrence was diagnosed 4.5-24.5 months after cryoablation (mean 5.7 months). Risk of tumor recurrence was associated with a smaller ablative margin from the edge of tumor to iceball ablation margin (multivariate hazard ratio 0.68, CI 0.48-0.95, P = .024).

CONCLUSIONS

CT-guided cryoablation is safe for local control of recurrent mesothelioma, with a low rate of complications and promising early-term efficacy. A smaller ablative margin may predispose to tumor recurrence.

[Organizing Pneumonia with High Radiotracer Concentration on Fluorodeoxyglucose-positron Emission Tomography, Mimicking Pleural Dissemination of Lung Cancer;Report of a Case]

A 68-year-old man was referred to our hospital because of an abnormal shadow in the chest roentgenogram. Chest computed tomography (CT) showed the nodule in the right upper lobe (S3), 17 mm in size. One month later, fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT scanning revealed positive reaction in the right upper lobe lesion and new lesion close to another lobe. In addition, interloblar small nodules were detected, 5 mm and 7 mm in size. A transbronchial brush cytology by bronchoscopy was performed, and the microscopic findings demonstrated the presence of atypical cells, suspected adenocarcinoma. The video-assisted thoracoscopic surgery was performed to establish a diagnosis and a treatment. Histopathological examination showed no malignancy and organizing pneumonia with inflammation. In case of the PET-positive solitary nodule increasing in size, organizing pneumonia should be included in the differential diagnosis.