Primary cysts and neoplasms of the mediastinum: recent changes in clinical presentation, methods of diagnosis, management, and results

[A rare posterior mediastinal tumor, extra- adrenal thoracic myelolipoma]

INTRODUCTION

Myelolipoma is a rare, benign, usually adrenal. tumor, In rare cases, it may be extra-adrenal, for example thoracic.

OBSERVATION

We report the case of the fortuitous discovery of a posterior mediastinal mass with a fatty component, not immediately identifiable on the PET scan. Because of the atypical appearance on imaging and the lack of diagnostic certainty, the patient received surgical management, which has ultimately made it possible to accurately diagnose and curatively remove extra-adrenal myelolipoma.

CONCLUSION

Most often incidentally detected, extra-adrenal myelolipoma is a rare tumor with a good prognosis. Management is primarily surgical. Monitoring of the lesion depends on its size and location.

[CA 19-9 Secreting Extralobar Sequestration Presenting as a Bifocal Posterior Mediastinal Tumour]

A 60-year-old female patient was referred for further diagnosis and treatment of a posterior mediastinal lesion. The lesion was incidentally discovered in a CT scan of the chest and abdomen, which had been performed due to an increased CA 19-9 in routine blood tests. At the time point of the referral, the lesion had already been biopsied twice (CT guided and through EUS) but the histopathology was inconclusive. Upon referral, we repeated the CT guided biopsy and the transoesophageal ultrasound. The latter did not reveal any invasion of the oesophagus. Both biopsies were inconclusive again. We discussed thoracoscopic exploration with the patient. The procedure began with a right uniportal VATS. The lesion originated in the right lower lobe. After dissection of the lesion from the right lower lobe and its adhesions to the diaphragm, the lesion was mobilised from the mediastinal adhesions. A supplying vessel from the descending aorta was ligated and the patient was turned in order to continue the procedure from the left side. During the left sided thoracoscopy, the lesion was dissected from the diaphragm and the descending aorta. There was no invasion of the lung on the left side. The lesion was pulled through the mediastinum between the aorta and the oesophagus and was successfully extracted through the left uniportal incision. The histopathological report revealed extralobar pulmonary sequestration.

Large Pericardial Cyst: The Role of the DaVinci Robotic System

Pericardial cysts are a rare but important differential diagnosis when considering mediastinal lesions. Cyst removal is commonly indicated for diagnostic purposes. Removal should also be considered in the context of infection and cyst growth, which could lead to compression of the right ventricle. We describe the case of a patient who underwent robotic-assisted excision of a pericardial cyst as well as the surgical management of such lesions.

Clinicopathological Analysis of Mediastinal Masses: a Single-Institute Experience

Background

The centrally located portion of the thoracic cavity is called the mediastinum and consists of several essential organs. In the presence of various outcomes and prognostic indicators of mediastinal masses, meticulous diagnosis of these masses is considered crucial.

Objective

In this study, we analyzed all mediastinal masses observed clinically and pathologically at one institution over a period of ten years.

Methods

This is a retrospective, single-institution review of 94 patients with mediastinal masses, drawing on existing data recorded by the hospital. The study was carried out at the King Fahd University Hospital, Khobar, Saudi Arabia. Data was collected from 2009 to 2019. Participants were all patients with malignant or benign mediastinal masses admitted to the hospital, or diagnosed incidentally to have mediastinal masses during investigations for other reasons.

Results

The mean age for developing a mediastinal mass was 33.89 ± 18.91 years of age. Most of the patients (69.1%) were symptomatic at presentation. Overall, (49.23%) of patients who were symptomatic at diagnosis had a malignant mass. Concerning pathologic diagnosis and presentation of the patient (symptomatic versus asymptomatic), there was a significant positive relationship between pathologic diagnosis and symptoms with a P value of 0.020. In our study, only 5.15% of cases experienced recurrence.

Conclusion

This study provides a great understanding of mediastinal tumor biology and the role of both radiotherapy and chemotherapy in increasing the survival rates of patients suffering from similar malignant conditions.

Multifocal neuromuscular hamartoma with smooth muscle and Schwannian components

A male in his early 20s with gastro-oesophageal reflux disease and severe weight loss was found to have two intrabdominal masses causing his symptoms: one in the gastro-oesophageal junction and the other occupying the coeliac plexus in the cardiophrenic region. These masses were surgically removed and sent to pathology where they were found to be smooth muscle hamartomas with Schwannian components. These represent a unique presentation of benign smooth muscle tumours that is not typically seen in young adults, especially in the cardiophrenic region involving the coeliac plexus.

A case of anterior mediastinal mature teratoma with severe inflammatory extension into the neck

BACKGROUND

We present the case of a rare occurrence of an anterior mediastinal mature teratoma extending into the neck, commonly referred to as a cervicothoracic mature teratoma.

CASE PRESENTATION

A 19-year-old female presented with right-sided neck pain and swelling, which were found to be attributed to a 14 cm cystic lesion originating from the right thyroid lobe and extending into the mediastinum. A diagnosis of mediastinal teratoma with extension to the neck was made. Robot-assisted thymectomy was initiated but was complicated by dense tumor adherence to the superior vena cava and brachiocephalic veins, prompting a switch to a midline sternotomy. Simultaneous resection of the right thyroid lobe was performed due to inflammation. The transition to a midline sternotomy allowed successful excision of the tumor, which was confirmed to be a mature teratoma confined to the thoracic region. The patient's favorable postoperative course led to discharge on day 5 with no recurrence at nine months.

CONCLUSIONS

Emphasizing the challenges and the importance of prompt intervention in the management of mediastinal teratomas with neck extension.

Case report: Thoracic schwannoma as a diagnostic pitfall in both 18F-Choline PET/CT and 18F-FDG PET/CT

We report increased 18F-FDG uptake in the right posterior mediastinal region in a 70-year-old woman following the discovery of a mass in the aftermath of a bronchitis episode. We also report increased 18F-Choline uptake in the right posterior mediastinal region in a 66-year-old man with newly discovered prostate cancer, which may indicate the presence of mediastinal metastases. Both patients had a thoracic MRI showing an intense gadolinium enhancement in the same region, consistent with thoracic schwannomas, which were subsequently proven histologically. This case highlights that schwannoma is a diagnostic pitfall in both 18F-FDG and 18F-Choline PET/CT.

A case series: uniportal VATS excision of pericardial cysts in symptomatic patients

BACKGROUND

Pericardial cysts are infrequent lesions. Most of these are asymptomatic and incidental findings during investigations for unrelated conditions. When they are symptomatic, they demonstrate most of the time a benign clinical course. Yet, treatment is sometimes necessary. Besides a (temporary) treatment as percutaneous aspiration, there is surgery as a definite treatment. The aim of the paper is to motivate the safety and efficacy of uniportal video assisted thoracoscopy (UVATS) for the excision of (giant) pericardial cysts and describe their (peri-)operative technique.

METHODS

In this retrospective, single center-based case series, we report all cases with a pericardial cyst who underwent a surgical excision by uniportal VATS (UVATS) between March 2022 and April 2023. Detailed patient characteristics, operation details, hospital length of stay and follow-up data were collected.

RESULTS

A total of 4 patients underwent excision of a pericardial cyst by UVATS. The follow-up ranged from 10 to 20 months. The mean diameter of the pericardial cyst was 124 mm. Median procedure time was 94 min. No per- and postoperative complications occurred. The median length of postoperative hospital stay was 2 days. All patients showed a clinically relevant improvement of the pre-operative symptoms.

CONCLUSIONS

Uniportal VATS excision for pericardial cysts is a safe and effective surgical procedure with good outcomes on symptom relief. Though, future comparative studies are urged to elucidate its value among other treatment options.

Spatiotemporal distribution of mediastinal neoplasms: A comprehensive multi-center study

OBJECTIVES

Mediastinal neoplasms are typical but uncommon thoracic diseases with increasing incidence and unfavorable prognoses. A comprehensive understanding of their spatiotemporal distribution is essential for accurate diagnosis and timely treatment. However, previous studies are limited in scale and data coverage. Therefore, this study aims to elucidate the distribution of mediastinal lesions, offering valuable insights into this disease.

MATERIALS AND METHODS

This multi-center, hospital-based observational study included 20 nationwide institutions. A retrospective search of electronic medical records from January 1st, 2009, to December 31st, 2020, was conducted, collecting sociodemographic data, computed tomography images, and pathologic diagnoses. Analysis focused on age, sex, time, location, and geographical region. Comparative assessments were made with global data from a multi-center database.

RESULTS

Among 7,765 cases, thymomas (30.7%), benign mediastinal cysts (23.4%), and neurogenic tumors (10.0%) were predominant. Distribution varied across mediastinal compartments, with thymomas (39.6%), benign cysts (28.1%), and neurogenic tumors (51.9%) most prevalent in the prevascular, visceral, and paravertebral mediastinum, respectively. Age-specific variations were notable, with germ cell tumors prominent in patients under 18 and aged 18-29, while thymomas were more common in patients over 30. The composition of mediastinal lesions across different regions of China remained relatively consistent, but it differs from that of the global population.

CONCLUSION

This study revealed significant heterogeneity in the spatiotemporal distribution of mediastinal neoplasms. These findings provide useful demographic data when considering the differential diagnosis of mediastinal lesions, and would be beneficial for tailoring disease prevention and control strategies.

Robotic excision of posterior mediastinal neurogenic tumours: Technique and surgical outcomes

INTRODUCTION

Neurogenic tumours are the most common tumours of the posterior mediastinum and account for 75% of the tumours in this region. Till recently, open transthoracic approach has been the standard of care for their excision. Thoracoscopic excision of these tumours is being commonly employed because of lesser morbidity and shorter hospital stay. The robotic surgical system offers a potential advantage over conventional thoracoscopy. We herein report our technique and surgical outcomes of excision of posterior mediastinal tumours using the Da Vinci Robotic Surgical System.

MATERIALS AND METHODS

We retrospectively reviewed 20 patients who underwent Robotic Portal-Posterior Mediastinal Tumour (RP-PMT) Excision at our centre. The demographic data, clinical presentation, characteristics of the tumour, operative and post-operative variables including, total operative time, blood loss, conversion rate, duration of the chest tube, hospital stay and complications were noted.

RESULTS

Twenty patients underwent RP-PMT Excision and were included in the study. The median age was 41.2 years. The most frequent presentation was chest pain. Schwannoma was the most common histopathological diagnosis. There were two conversions. The total operative time was 110 min with an average blood loss of 30 mL. Two patients developed complications. The postoperative hospital stay was 2.4 days. With a median follow-up of 36 months (6-48 months), all except patients are recurrence-free, except the patient with malignant nerve sheath tumour who developed local recurrence.

CONCLUSION

Our study demonstrates the feasibility and safety of robotic surgery for posterior mediastinal neurogenic tumours with good surgical outcomes.

An Undifferentiated Primary Mediastinal Carcinoma Compressing the Main Pulmonary Artery: A Rare Cause of Right Ventricular Strain

Undifferentiated carcinoma (or poorly differentiated carcinoma) of the mediastinum is a relatively rare pathological variant of anterior mediastinal tumors. Pathologists usually use the term to describe an epithelial tumor with no histological features that enable the identification of its site of origin. Invasion of adjacent vital cardiopulmonary structures is among the most problematic complications of anterior mediastinal masses. We report a case of a 60-year-old male presenting with easy fatiguability, significant weight loss, and chest pain. A CT scan of the chest revealed a large anterior mediastinal mass, compression of the main pulmonary artery, and a large pericardial effusion. The patient underwent pericardiocentesis, emergent radiotherapy, and platinum-based chemotherapy. His condition dramatically improved, and he was subsequently discharged home for further follow-up.

Non-Neoplastic Thoracic Cysts: A Clinicopathologic Study of 136 Cases

Benign cysts of the thoracic cavity represent a group of rare lesions, the spectrum of which is expanding. Most of these are congenital in nature, secondary to abnormal development during embryogenesis while a smaller subset represents acquired lesions. We retrospectively reviewed the clinicopathologic features of 136 patients with thoracic cysts that were treated in our institution over a span of 20 years. The patients were 85 female and 51 male patients with an average age of 51 years. Eighty-four of the patients were asymptomatic (62%), the remainder mainly presented with chest pain, shortness of breath, or cough. Surgical resection was performed in 123 patients while 12 patients were treated with aspiration only and 1 underwent core biopsy. The cyst size ranged from 0.5 to 14.8 cm (mean, 4.4 cm); histologically, the lesions included 50 thymic cysts (28 multilocular; 22 unilocular), 37 bronchogenic cysts, 23 pleuropericardial cysts, 12 unclassified cysts, 6 Müllerian cysts, 5 enteric cysts, and 3 parathyroid cysts. Clinical follow-up revealed that 97 patients were alive and well 4 months to 37 years after initial diagnosis; 25 patients were lost to follow-up and 14 patients died of unrelated causes. The current study is one of the largest studies on the subject with emphasis on clinicopathologic characteristics. This series has a higher incidence of thymic cysts compared with prior publications and covers a wider spectrum of different histologic types than previously reported.

Surgical Management of Pericardial Cysts: A Single-Center Retrospective Study

Introduction Pericardial cysts (PCs) are infrequent, non-malignant, and congenital abnormalities. The identification and treatment of PCs remain a significant challenge, with limited research on surgical management. Methods We performed a retrospective study of patients with PCs who underwent surgical intervention at the First Affiliated Hospital of Xinjiang Medical University from February 2002 to December 2022. Results A total of 55 patients underwent surgery due to PCs during the study period. Thirty-one were females and 24 were males. The average age of the patients was 44.7 ± 12.9 (six to 63 years old). PCs were located in the right hemithorax in 50 (90.9%) patients and left hemithorax in five (9.1%) patients. Approach methods were video-assisted thoracoscopic surgery (VATS) in 43 (78.2%) cases; thoracotomy in 11 (20%) cases, and median sternotomy in one (1.8%) cases. The average postoperative hospitalization period was 5.6 days (two to 14 days). Three patients developed postoperative complications (two pleural effusion, one pneumonia), whereas no mortality was observed in any patient due to the operation. Forty-one patients (74.5%) were followed up for three months to eight years postoperatively, during which no recurrent cysts were detected. Conclusion In this single-center retrospective study, we demonstrated that pericardial cyst cure is an appropriate operation according to cyst characteristics. VATS has been shown to be highly effective and safe in patients with PCs, offering the advantage of reducing postoperative morbidity efficiently.

Multilocular thymic cyst detected during COVID‑19 treatment in an HIV‑positive adult man: A case report and literature review

A multilocular thymic cyst (MTC) is a rare mediastinal tumor with multiloculated cyst-like structures in the anterior mediastinum. This tumfor is associated with inflammatory diseases, including human immunodeficiency virus (HIV) infection. The present study reports a case of MTC detected during coronavirus disease 2019 (COVID-19) treatment in an adult who was tested HIV positive. An anterior mediastinal tumor was incidentally detected on computed tomography in a 52-year-old man with a 20-year history of HIV infection on the 9th day of COVID-19. The patient was asymptomatic with no notable physical findings. Magnetic resonance imaging revealed a 28-mm bilocular cyst. Robot-assisted thoracoscopic tumor resection was performed. Pathological examination showed that the cyst was lined with squamous or cuboidal epithelium, and the cystic lesion wall was mainly composed of thymic tissue with follicular hyperplasia. Based on these findings, the patient was diagnosed with MTC. To date, only 15 MTC cases have been reported in patients with HIV, and the majority of cases showed HIV infection-related symptoms such as lymphoid interstitial pneumonia and parotid gland enlargement. The present case was atypical for an HIV-related MTC because it did not involve HIV infection-related symptoms, suggesting the possibility for an alternative etiology such as COVID-19. Further reports on MTC development in patients with COVID-19 are required to elucidate the relationship between MTC and COVID-19.

Intrathoracic neurogenic tumors (ITNs): Management of solid and cystic lesions

BACKGROUND

Intrathoracic neurogenic tumors (INTs) are derived from nerve tissue and grow within the chest. Preoperative diagnosis can be challenging and only complete surgical exeresis enables confirmation of the suspected diagnosis. Here, we analyzed our experience on management of paravertebral lesions with solid and cystic patterns.

METHODS

A monocentric retrospective study was conducted, which included 25 consecutive cases of ITNs in the period from 2010 to 2022. These cases had been surgically treated by thoracoscopic resection alone, or in combination with neurosurgery in the case of dumbbell tumors. The demographic and operative data along with complications were recorded and analyzed.

RESULTS

Twenty-five patients were diagnosed with a paravertebral lesion of which 19 (76%) had solid features and six (24%) had cystic features. The most common diagnosis was schwannoma (72%), followed by neurofibroma (20%) and malignant schwannoma (8%). In four cases (12%) the tumor showed an intraspinal extension. None of the patients had recurrence until 6 months of follow-up. Comparison between the VATS and thoracotomy procedures showed that outcome of discharge on the postoperative day, on average, was 2.61 ± 0.5 versus 3.51 ± 0.53, respectively (p-value <0.001).

CONCLUSION

The treatment of choice for INTs is complete resection which is tailored to tumor size, location, and extension. In our study, paravertebral tumors with cystic characteristics were not associated with an intraspinal extension and did not show a different behavior from solid tumors.

Clinico-Pathological and Radiological Spectrum of Mediastinal Masses in a Tertiary Care Center: A Cross-Sectional Study

Introduction The phrase "mediastinal mass" refers to a mass within the mediastinum. About 50% of all mediastinal masses, including teratoma, thymoma, lymphoma, and thyroid illness, are anterior mediastinal tumors. Data on the mediastinal mass in India are relatively sparse, especially in this region, compared to those from other countries. Mediastinal masses are very infrequent lesions that might occasionally present a diagnostic and therapeutic challenge to the doctor. The current study describes the socio-demographic characteristics, symptoms, diagnosis, and location of mediastinal mass among the study participants. Methodology We carried out a retrospective, cross-sectional study in a tertiary care center in Chennai for three years. We included patients with an age above 16 years who visited the tertiary care center in Chennai during the study period. We included all patients with a mediastinal mass diagnosed by CT scan, with or without signs and symptoms of mediastinal compression. Patients under the age of 16 and those with insufficient data were both excluded from the study. As per the universal sampling technique, we included all the patients who met the eligibility criteria during the study period (three years) as study subjects. By using the hospital records, we collected all data about the patients like socio-demographic data, presenting complaints, past history, x-ray findings, and co-morbidities. Similarly, we recorded blood parameters, pleural fluid parameters, and histopathological reports from the laboratory register. Results The mean age of the study participants was 41.11 years, with a high proportion of patients belonging to the age group of 21 to 30 years. Over 70% of the study participants were male. Only about 54.5% of the study participants had symptoms because of a mediastinal mass. The most common local symptom felt by the patients was dyspnea, followed by a dry cough. Weight loss was the most common symptom for the patients. Most study participants (47.7%) had seen a doctor within one month of the onset of symptoms. About 4.5% of the patients had pleural effusion, as diagnosed by x-ray. Most of the study participants had a mass in the anterior mediastinum, followed by the posterior mediastinum. Most of the participants (15.9%) had non-caseating granulomatous inflammation suggestive of sarcoidosis.  Conclusion The most common tumor found in our study was lymphoma, which was followed by non-caseating granulomatous disease and thymoma. Anterior compartments are most commonly involved. We observed the most common presentation in the third decade of life with a male to female ratio of 2:1, with dyspnea being the most common symptom, followed by a dry cough. Our study found 4.5% of the patients had pleural effusion as a complication.

Diagnostic approach for mediastinal masses with radiopathological correlation

PURPOSE

Mediastinal masses have various histopathological and radiological findings. Although lymphoma is the most common type of tumor, thymic epithelial and neurogenic tumors are common in adults and children, respectively, but several other types are difficult to distinguish. No previous review has simply and clearly shown how to differentiate mediastinal masses.

METHOD

We conducted a review of the latest mediastinal classifications and mass differentiation methods, with a focus on neoplastic lesions. Both older and recent studies were searched, and imaging and histopathological findings of mediastinal masses were reviewed. Original simple-to-use differentiation flowcharts are presented.

RESULTS

Assessing localizations and internal characteristics is very important for mediastinal mass differentiation. The mass location and affected organ/tissue should be accurately assessed first, followed by more qualitative diagnosis, and optimization of the treatment strategy. In 2014, the International Thymic Malignancy Interest Group presented a new mediastinal clinical classification. In this classification, mediastinal masses are categorized into three groups according to location: prevascular (anterior)-, visceral (middle)-, and paravertebral (posterior)-compartment masses. Then, the internal characteristics and functional images are evaluated.

CONCLUSIONS

Differentiation of mediastinal masses is very difficult. However, if typical imaging findings and clinical characteristics are combined, reasonable differentiation is possible. In each patient, proper differential diagnosis may contribute to better treatment selection.

Primary mediastinal germ cell tumors

Mediastinal germ cell tumors share similar histopathological, immunohistochemical, and molecular features with their counterparts in the gonads. Therefore, proper clinical and radiological evaluation of patients with an anterior mediastinal mass becomes essential in the final interpretation of these tumors. The gold standard for the diagnosis of these tumors remains histopathological evaluation. However, immunohistochemical stains and molecular studies also provide an aid in cases in which the histology is not typical. It is also important to keep in mind that a small mediastinoscopic biopsy may not be representative of the entire neoplasm. In this review, we will provide our perspective regarding histopathological diagnosis, staging, immunohistochemical and molecular profile, and briefly family of tumors address pertinent epidemiological, clinical and treatment options. However, the main emphasis is to review the process of pathological assessment in pre and post-treated tumors. Knowledge of the different growth patterns and histological associations is important, mainly when confronted with mediastinoscopic biopsies, which ultimately will determine treatment options.

The role of minimally invasive surgery in the management of giant mediastinal tumors: a narrative review

BACKGROUND AND OBJECTIVE

Beyond diagnosis, minimally invasive surgery has traditionally not been considered suitable for large tumors, those invading vital structures or high-risk patients. However, with the improvement of multimodality treatments able to reduce tumor size preoperatively, patient evaluation and selection, perioperative care (including both surgical and anesthesiological techniques) and postoperative management, the indications of minimally invasive surgery, even in giant mediastinal tumors, have increased and will continue to broaden in future years. This review aims to summarize the existing literature regarding the role of minimally invasive surgery in the management of giant mediastinal tumors. We have focused in the role minimally invasive surgery has in diagnosis and treatment of these tumors and we have tried to provide an updated perspective to identify future applications and work-directions.

METHODS

Data regarding minimally invasive surgery in giant mediastinal tumors are limited, including a proper definition of them. We performed a PubMed search of English and Spanish written studies until August 2021.

KEY CONTENT AND FINDINGS

There is limited data related to minimally invasive surgery in giant mediastinal tumors and much of the literature review we have performed has yielded isolated case reports, case series with a low number of cases or editorials. Although the role of minimally invasive surgery is well consolidated as a diagnostic approach, adequate patient selection, hospital volume and experience, multidisciplinary discussion of candidates, patient safety and adequate oncological resection remain the most important aspects to be taken into account when considering a minimally invasive approach for a giant mediastinal tumor.

CONCLUSIONS

With careful and multidisciplinary perioperative planning, minimally invasive surgery has shown to be safe and to provide at least similar outcomes when compared to open approaches in well selected cases. Although data is still limited, improved surgical techniques and available technology will pave the way to increased indications of minimally invasive surgery in giant mediastinal tumors.

Multiparameter diagnostic model based on 18F-FDG PET and clinical characteristics can differentiate thymic epithelial tumors from thymic lymphomas

OBJECTIVE

To evaluate the diagnostic performance of combined multiparametric ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG PET) with clinical characteristics in differentiating thymic epithelial tumors (TETs) from thymic lymphomas.

PATIENTS AND METHODS

A total of 173 patients with 80 TETs and 93 thymic lymphomas who underwent ¹⁸F-FDG PET/CT before treatment were enrolled in this retrospective study. All patients were confirmed by pathology, and baseline characteristics and clinical data were also collected. The semi-parameters of ¹⁸F-FDG PET/CT, including lesion size, SUVmax (maximum standard uptake value), SUVmean (mean standard uptake value), TLG (total lesion glycolysis), MTV (metabolic tumor volume) and SUVR (tumor-to-normal liver standard uptake value ratio) were evaluated. The differential diagnostic efficacy was evaluated using the receiver operating characteristic (ROC) curve. Integrated discriminatory improvement (IDI) and net reclassification improvement (NRI), and Delong test were used to evaluate the improvement in diagnostic efficacy. The clinical efficacy was evaluated by decision curve analysis (DCA).

RESULTS

Age, clinical symptoms, and metabolic parameters differed significantly between patients with TETs and thymic lymphomas. The ROC curve analysis of SUVR showed the highest differentiating diagnostic value (sensitivity = 0.763; specificity = 0.888; area under the curve [AUC] = 0.881). The combined diagnostics model of age, clinical symptoms and SUVR resulted in the highest AUC of 0.964 (sensitivity = 0.882, specificity = 0.963). Compared with SUVR, the diagnostic efficiency of the model was improved significantly. The DCA also confirmed the clinical efficacy of the model.

CONCLUSIONS

The multiparameter diagnosis model based on ¹⁸F-FDG PET and clinical characteristics had excellent value in the differential diagnosis of TETs and thymic lymphomas.

Thoracoscopic management of posterior mediastinal neurogenic tumours

Background:

This study describes the surgical technique of thoracoscopic resection of posterior mediastinal neurogenic tumours and reporting the surgical outcomes.

Methods:

This is a retrospective analysis of 21 patients operated over 7 years in a dedicated thoracic surgery centre. The demographic and post-operative parameters along with complications were recorded and analysed.

Results:

Twelve patients had right-sided tumours, while 9 had left-sided lesions, and 9 were on the left side. The most common diagnosis was schwannoma (n = 15, 71.42%), followed by neurofibroma (n = 4, 19.04%). The average surgery duration was 104 min (85–135 min), and the mean blood loss was 120 ml (25 ml–250 ml). The average lesion size was 4.8 cm (2 cm–7 cm). Conversion to open procedure was required in one patient. Two patients (14.2%) developed complications. One patient developed Horner's Syndrome and the other developed post-operative lung atelectasis. The median follow-up was 36 months (6–90 months). No recurrence was observed during the follow-up period.

Conclusions:

Thoracoscopic approach to posterior mediastinal neurogenic tumours is feasible and allows for low morbidity, short hospital stay and superior cosmesis.

Epicardial mesothelial cyst originating from the roof of the left atrium: a case report

Background

Epicardial mesothelial cysts are cysts that are attached to the epicardium within the pericardial cavity. Reports on epicardial mesothelial cysts are rare, and limited studies have investigated their surgical management. Here, we report the rare case of an epicardial cyst originating from the roof of the left atrium.

Case summary

A 73-year-old man with dyspnoea on exertion and lower limb oedema was diagnosed with a giant cyst (diameter, 7 cm × 4.5 cm) in the pericardial cavity using computed tomography. Off-pump surgery was performed with successful resection of the cyst with a pedicle connected to the roof of the left atrium. Histological examination confirmed the mesothelial origin of the tumour cells.

Conclusion

Cysts rarely develop within the pericardial cavity, especially an epicardial cyst. The few studies exploring this disease have suggested that patients with this condition may be asymptomatic or have mild breathlessness or cardiac tamponade, which might be occasionally or incidentally diagnosed. Sufficient preoperative evaluation, particularly involving the coronary artery, is essential, and a rational way of surgery should be planned considering all factors.

An Incidental Finding of a Large Pericardial Cyst

A pericardial cyst is a rare and benign cause of a mediastinal mass. They are frequently asymptomatic and are usually incidental findings on imaging. Symptoms may include persistent cough, atypical chest pain, dysphagia, and dyspnea. Diagnosis is usually established with the aid of imaging, including a chest x-ray, a computed tomography (CT) scan, and magnetic resonance imaging (MRI). Therapeutic options include surgical resection or aspiration for large and/or symptomatic cysts, whereas conservative management with routine follow-up is advised for small or asymptomatic cysts. We herein describe the case of a 48-year-old lady, who presented with clinical features suggestive of acute cholecystitis, with an incidental finding of a pericardial cyst, measuring approximately 10.1 cm x 8.7 cm x 10.7 cm. The patient underwent video-assisted thoracoscopic surgery (VATS) for excision of the pericardial cyst. She had an uneventful recovery and was discharged on the second post-operative day. At six months, there was no evidence of disease recurrence.

Transesophageal endoscopic resection of mediastinal cysts (with video)

BACKGROUND AND AIMS

Primary mediastinal cysts are infrequent lesions derived from a variety of mediastinal organs or structures. Complete surgical resection is the treatment of choice even in asymptomatic patients to prevent severe adverse events (AEs) and to establish the diagnosis. Transesophageal endoscopic resection of benign mediastinal tumors has been proven feasible. The aim of this study was to evaluate the feasibility, safety, and efficacy of transesophageal endoscopic surgery for mediastinal cysts.

METHODS

From January 2016 to May 2021, patients with mediastinal cysts who underwent transesophageal endoscopic resection were retrospectively included. Clinicopathologic characteristics, procedure-related parameters, AEs, and follow-up outcomes were analyzed.

RESULTS

Ten patients with mediastinal cysts were included in this study. The mean cyst size was 3.3 ± 1.3 cm. Histopathology revealed 3 bronchogenic cysts (30.0%), 4 esophageal duplication cysts (40.0%), 2 gastroenteric cysts (20.0%), and 1 lymphatic cyst (10.0%). All procedures were performed uneventfully without conversion to traditional surgery. En-bloc resection was achieved in 6 patients (60.0%). Aggressive resection was avoided to prevent damage to the surrounding vital organs. Mean resection time and suture time were 58.0 ± 36.4 minutes and 5.4 ± 1.0 minutes, respectively. No major pneumothorax, bleeding, mucosal injury, or fistula occurred. One patient had a transient febrile episode (>38.5°C). Mean postoperative hospital stay was 2.7 ± .9 days. No residual or recurrent lesions were observed in any patient during a mean follow-up period of 29.8 ± 19.5 months.

CONCLUSIONS

Transesophageal endoscopic surgery appears to be a feasible, safe, effective, and much less invasive approach for mediastinal cyst resection. Larger prospective studies are required to fully assess the efficacy and safety of this novel technique.

[Mediastinal Tumors]

If mediastinal tumours cause symptoms these are related to their anatomical localization or a paraneoplastic syndrome. The differential diagnosis is based on the clinical situation with finding the lesion, and, furthermore, taking into account the age and sex of the patient, and the mediastinal compartment where the lesion is located. Cross-sectional radiographic diagnostic is essential for defining the therapeutic strategy. The anterior mediastinum is dominated by thymic tumours, mediastinal lymphomas, germ cell tumours and ectopic mediastinal poiters. The middle mediastinal compartment is the most frequent place of mediastinal cystic tumours, whereas the posterior mediastinum is the domain of neurogenic tumours. For selected cases a tissue biopsy is required. Surgery is the mainstay for most mediastinal tumours. Median sternotomy is the most frequent conventional surgical technique while minimally invasive surgery with thoracoscopic and above all robot assisted operation techniques are increasingly frequent. Combined chemotherapy and modern radiotherapy are essential components of the comprehensive treatment for mediastinal tumours.

Special Computed Tomography Imaging Features of Thymic Cyst

OBJECTIVE

To explore the features and diagnostic value of computed tomography (CT) imaging in cases of thymic cysts.

METHODS

A total of 24 cases of the thymic cysts (confirmed by postoperative pathology) were retrospectively analyzed. The location, morphology, and density of the thymic cysts were summarized, and the changes in CT value of the region of interest (ROI) in the thymic cysts between noncontrast enhanced and enhanced chest scans were compared and classified.

RESULTS

The average long-axis dimension was 17.50 ± 6.00 mm, the CT value range across the 24 cases was 5-81 HU, and the average CT value of the noncontrast enhanced scans was 39.75 ± 20.66 HU. The CT value in the noncontrast enhanced scan was >20 HU in 79% of the sample cases. The CT value in the ROI of the thymic cysts under enhanced scan showed a significant decrease in 15 cases, a significant increase in 5 cases, and an insignificant change in 4 cases.

CONCLUSION

The CT values of the thymic cysts in the enhanced scans were generally lower than in the noncontrast enhanced scans, which might be a valuable finding for thymic cysts diagnosis.

Lymphatic Node Metastasis Risk Scoring System: A Novel Instrument for Predicting Lymph Node Metastasis After Thymic Epithelial Tumor Resection

BACKGROUND

The authors aimed to create a novel model to predict lymphatic metastasis in thymic epithelial tumors.

METHODS

Data of 1018 patients were collected from the Surveillance, Epidemiology, and End Results database from 2004 to 2015. To construct a nomogram, the least absolute shrinkage and selection operator (LASSO) regression model was used to select candidate features of the training cohort from 2004 to 2013. A simple model called the Lymphatic Node Metastasis Risk Scoring System (LNMRS) was constructed to predict lymphatic metastasis. Using patients from 2014 to 2015 as the validation cohort, the predictive performance of the model was determined by receiver operating characteristic (ROC) curves.

RESULTS

The LASSO regression model showed that age, extension, and histology type were significantly associated with lymph node metastasis, which were used to construct the nomogram. Through analysis of the area under the curve (AUC), the nomogram achieved a AUC value of 0.80 (95 % confidence interval [Cl] 0.75-0.85) in the training cohort and 0.82 (95 % Cl 0.70-0.93) in the validation cohort, and had closed calibration curves. Based on the nomogram, the authors constructed the LNMRS model, which had an AUC of 0.80 (95 % Cl 0.75-0.85) in the training cohort and 0.82 (95% Cl 0.70-0.93) in the validation cohort. The ROC curves indicated that the LNMRS had excellent predictive performance for lymph node metastasis.

CONCLUSION

This study established a nomogram for predicting lymph node metastasis. The LNMRS model, constructed to predict lymphatic involvement of patients, was more convenient than the nomogram.

Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach

The diagnosis of a mediastinal mass may be challenging for clinicians, since lesions arising within the mediastinum include a variety of disease entities, frequently requiring a multidisciplinary approach. Age and sex represent important information, which need to be integrated with imaging and laboratory findings. In addition, the location of the mediastinal lesion is fundamental; indeed, we propose to illustrate mediastinal diseases based on the compartment of origin. We consider that this structured approach may serve as hint to the diagnostic modalities and management of mediastinal diseases. In this review, we present primary mediastinal tumours in the evolving context of new diagnostic and therapeutic tools, with recently described entities, based on our own experience with >900 cases encountered in the past 10 years.

Given the mediastinal anatomical heterogeneity, the correct positioning of mediastinal lesions becomes primal, in order to first establish a clinical suspicion and then to assist in planning biopsy and surgical procedurehttps://bit.ly/3p0gsk3

Cardiovascular magnetic resonance of cardiac tumors and masses

Cardiac masses diagnosis and treatment are a true challenge, although they are infrequently encountered in clinical practice. They encompass a broad set of lesions that include neoplastic (primary and secondary), non-neoplastic masses and pseudomasses. The clinical presentation of cardiac tumors is highly variable and depends on several factors such as size, location, relation with other structures and mobility. The presumptive diagnosis is made based on a preliminary non-invasive diagnostic work-up due to technical difficulties and risks associated with biopsy, which is still the diagnostic gold standard. The findings should always be interpreted in the clinical context to avoid misdiagnosis, particularly in specific conditions (e.g., infective endocarditis or thrombi). The modern multi-modality imaging techniques has a key role not only for the initial assessment and differential diagnosis but also for management and surveillance of the cardiac masses. Cardiovascular magnetic resonance (CMR) allows an optimal non-invasive localization of the lesion, providing multiplanar information on its relation to surrounding structures. Moreover, with the additional feature of tissue characterization, CMR can be highly effective to distinguish pseudomasses from masses, as well as benign from malignant lesions, with further differential diagnosis of the latter. Although histopathological assessment is important to make a definitive diagnosis, CMR plays a key role in the diagnosis of suspected cardiac masses with a great impact on patient management. This literature review aims to provide a comprehensive overview of cardiac masses, from clinical and imaging protocol to pathological findings.

Myocardial infarction revealing a pleuropericardial cyst: a case report

Pericardial cysts are a rare entity, accounting for 6-7 percent of all mediastinal masses. They are frequently congenital relating to a failure of fusion of mesenchymal layers forming the pericardial space. Pericardial cysts are considered rare incidental findings, they are mostly asymptomatic and benign, however life-threatening complications may occur. Here we present a case of a silent pericardial cyst that was discovered by chance while performing transthoracic echocardiography (TTE) for a man who was admitted for myocardial infarction.

Mediastinal Germ Cell Tumors: A Review and Update on Pathologic, Clinical, and Molecular Features

Mediastinal germ cell tumors (MGCTs) are the most common extragonadal germ cell tumors (GCTs) and most often arise in the anterior mediastinum with a male predilection. MGCTs also have a predilection for patients with Klinefelter syndrome and possibly other genetic conditions. MGCTs, as GCTs at other extragonadal sites, are thought to arise from germ cells improperly retained during migration along the midline during embryogenesis. Similar to their counterparts in the testes, MGCTs are classified into seminomatous and nonseminomatous GCTs. Seminomatous MGCT represents pure seminoma, whereas nonseminomatous MGCTs encompass pure yolk sac tumors, embryonal carcinoma, choriocarcinoma, mature or immature teratoma, and mixed GCTs with any combination of GCT types, including seminoma. Somatic-type or hematologic malignancies can also occur in association with a primary MGCT. MGCTs share molecular findings with GCTs at other sites, most commonly the presence of chromosome 12p gains and isochromosome i(12p). Treatment includes neoadjuvant chemotherapy followed by surgical resection of residual tumor, with the exception of benign teratomas, which require only surgical resection without chemotherapy. In this review, we highlight and provide an update on pathologic, clinical, and molecular features of MGCTs. Immunohistochemical profiles of each tumor type, as well as differential diagnostic considerations, are discussed.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

Robotic approach has improved outcomes for minimally invasive resection of mediastinal tumors

BACKGROUND

The optimal minimally invasive surgical (MIS) approach to mediastinal tumors is unknown. There are limited reports comparing the outcomes of resection with robotic-assisted and video-assisted thoracoscopy (RATS vs VATS). We hypothesized that patients who underwent RATS would have improved outcomes.

METHODS

The National Cancer Database was queried for all patients who underwent MIS for any mediastinal tumor from 2010-2016. Patients were determined to have an adverse composite outcome if they had any of the adverse perioperative outcomes; conversion to open procedure, 90-day mortality, 30-day readmission, and positive pathologic margins. Secondary outcomes of interest were length-of-stay (LOS) and overall survival. Multivariable logistic regression was used to assess likelihood of having a composite adverse outcome based on surgical approach.

RESULTS

856 patients were included: 402 (47%) underwent VATS and 454 (53%) underwent RATS. RATS resections were associated with fewer conversions (4.9% vs 14.7%, p<0.001), fewer positive margins (24.3% vs 31.6%, p=0.02), shorter LOS (3.8d vs 4.3d, p=0.01) and less composite adverse events (36.7% vs 51.3%, p<0.001). Multivariate analysis showed RATS (OR 0.44, p<0.001) was independently associated with decreased likelihood of composite adverse outcome, even among tumors >4 cm (OR 0.45, p=0.001). Overall survival was similar between the two groups.

CONCLUSIONS

Among patients who underwent MIS for a mediastinal tumor, RATS had fewer adverse outcomes than VATS, even for tumors ≥4 cm. These data suggests that RATS may be the preferred technique for patients who are candidates for minimally invasive resection of mediastinal tumors.

Primary mediastinal germ cell tumours with high prevalence of somatic malignancy: An experience from a single tertiary care oncology centre

BACKGROUND

Primary mediastinal germ tumours (PMGCT) constitute, a mere 3-4% of all germ cell tumours (GCT). Although they account for approximately 16% of mediastinal tumours in adults and 19-25% in children as per western literature, there is hardly any large series on PMGCT reported from the Indian subcontinent.

DESIGN

We have retrospectively analysed clinicopathological features of 98 cases of PMGCT diagnosed over 10 years (2010-2019) from a tertiary-care oncology centre.

RESULTS

The study group (n = 98) comprised predominantly of males (n = 92) (M:F ratio-15:1), with an age range between 3 months to 57 years (median: 25 years). The tumours were predominantly located in the anterior mediastinum (n = 96). Broadly, Non-seminomatous germ cell tumours (NSGCT) were more common (n = 73, 74%) compared to pure seminoma (n = 25, 26%). Mixed NSGCT was the most common histological subtype (n = 30) followed by pure mature teratoma (n = 18), pure Yolk sac tumour (n = 13), mixed seminoma and NSGCT (n = 5), pure immature teratoma (n = 3) and GCT; NOS (n = 4). Interestingly, all female patients had exclusive teratomas. Nine cases revealed secondary somatic malignancy (5 carcinomas and 4 sarcomas). The majority of patients received neoadjuvant chemotherapy (n = 71). Surgical excision was performed in 60 patients. Follow up was available in 68 patients. NSGCT showed a poor prognosis as compared to seminoma (p value = 0.03) and tumours with somatic malignancies had a more aggressive clinical course.

CONCLUSION

PMGCT was seen predominantly in young adult males and somatic malignancies were noted in as high as 9% of cases. Patient with somatic malignancy have aggressive clinical course, hence, extensive sampling and careful histopathological evaluation are recommended for the identification and definitive characterization.

Mesothelial Cysts

OBJECTIVES

Peritoneal mesothelial cysts have been reported under various terms, including benign cystic mesothelioma, usually in the form of case reports/series, whereas extraperitoneal cases are rarely reported. Our objective was to report the detailed characteristics of cystic lesions of the serosal cavities.

METHODS

We retrospectively examined the clinicopathologic findings of a series of mesothelial cystic lesions (n = 79).

RESULTS

Most cases (n = 68, 86%) concerned the peritoneum, whereas 11 (14%) concerned the pericardium. No pleural cases were found. A total of 51 (64.5%) lesions were solitary, whereas 28 (35.5%) were multiple. Peritoneal lesions harbored a plump eosinophilic mesothelium and a loose connective stroma, whereas pericardial lesions showed a cuboidal/flattened mesothelium, collagenous stroma, intense inflammation, and other tissue types, like adipose and muscle tissue. Solitary peritoneal lesions are usually extrapelvic and found in older patients incidentally during other surgeries, whereas multiple lesions are found in younger patients and usually in the pelvis. The lesions show a benign clinical course with rare recurrences but no malignant transformation.

CONCLUSIONS

Most mesothelial cysts are peritoneal and rarely pericardial. Peritoneal cysts differ from pericardial cysts. Peritoneal solitary lesions differ from multiple lesions, also suggesting their pathogenetic differences.

Multimodality treatment outcome in patients with primary malignant mediastinal germ cell tumor in adults

BACKGROUND

Malignant mediastinal germ cell tumor (MGCT) is rare and has poor outcomes even after multimodality treatment. Data from resource-poor countries are scarce in the literature.

AIMS

To evaluate the clinicopathologic features and treatment outcome of primary malignant MGCT at our center.

METHODS AND RESULTS

Single institutional data review of patients aged ≥18 years, treated with a diagnosis of malignant MGCT between Nov'2013 and Nov'2019. Risk stratification was done as per International Germ Cell Cancer Collaborative Group (IGCCCG) classification. Patients were treated with platinum based chemotherapy and surgical resection for the residual disease was performed in non-seminomatous histology.28 patients had MGCT with a median age of 25 years (range:18-36) and all were male. Seven patients had superior vena cava obstruction (SVCO) at diagnosis and pre-treatment histological diagnosis was available in 23 (82%) patients. Seven (25%) patients had seminoma histology, all were of good risk as per IGCCCG risk criteria, whereas others had non-seminoma histology with poor-risk group. Seven patients with seminoma histology achieved a complete response after initial treatment. Six patients with non-seminoma histology underwent complete resection of residual disease post-chemotherapy and five revealed residual viable tumors. After a median follow-up of 10.8 months (range:2.9-75), 3-year progression-free survival (PFS) and overall survival (OS) estimate was 61.2% and 94.7% in the whole cohort, respectively and 3-year PFS and OS estimate was 100% in patients with seminoma histology.

CONCLUSIONS

This is the largest data set of MGCT patients' outcomes reported from India with multi-modality treatment. All patients were male and one-fourth had SVCO at presentation. Seminoma histology patients had a 100% outcome after initial platinum based chemotherapy. But, those with non-seminoma histology had a poor outcome even with chemotherapy and surgery.

Proton therapy for thoracic malignancies: a review of oncologic outcomes

Introduction: Radiotherapy is an integral component in the treatment of the majority of thoracic malignancies. By taking advantage of the steep dose fall-off characteristic of protons combined with modern optimization and delivery techniques, proton beam therapy (PBT) has emerged as a potential tool to improve oncologic outcomes while reducing toxicities from treatment.Areas covered: We review the physical properties and treatment techniques that form the basis of PBT as applicable for thoracic malignancies, including a brief discussion on the recent advances that show promise to enhance treatment planning and delivery. The dosimetric advantages and clinical outcomes of PBT are critically reviewed for each of the major thoracic malignancies, including lung cancer, esophageal cancer, mesothelioma, thymic cancer, and primary mediastinal lymphoma.Expert opinion: Despite clear dosimetric benefits with PBT in thoracic radiotherapy, the improvement in clinical outcomes remains to be seen. Nevertheless, with the incorporation of newer techniques, PBT remains a promising modality and ongoing randomized studies will clarify its role to determine which patients with thoracic malignancies receive the most benefit. Re-irradiation, advanced disease requiring high cardio-pulmonary irradiation volume and younger patients will likely derive maximum benefit with modern PBT.

Long-term outcome in mediastinal malignancies: video-assisted thoracoscopic versus open surgery

Purpose

There are not many studies comparing long-term oncological outcomes between video-assisted thoracoscopic surgery (VATS) and open surgery for mediastinal malignancies. This study aimed to compare perioperative and long-term outcomes of these two techniques in the treatment of mediastinal malignancies.

Methods

This is a retrospective study: patients with mediastinal malignancies underwent VATS or open surgery from 2010 to 2013 and were followed until 2019. The primary endpoints were long-term oncological outcomes, including tumor recurrence and mortality. Secondary endpoints were perioperative outcomes (operative duration, blood loss, pain, chest drainage duration, hospital length of stay, and complications).

Results

There were 36 patients in the VATS group and 49 patients in the open group. The median follow-up duration was 90 months. VATS significantly reduced operation time (84.6 versus 124.8 min), blood loss (59.8 versus 235.2 ml), postoperative pain score (4.9 versus 6.7), the duration of chest tube drainage (2.1 versus 3.1 days), and postoperative hospital stay (5.2 versus 8.0 days). The two groups were comparable regarding the recurrence rate (2.4 versus 2.1/100 person-years) and mortality rate (0.8 versus 0.9/100 person-years).

Conclusion

Compared with open surgery, VATS is less traumatic, reduces postoperative chest drainage, and shortens hospital stay with comparable long-term oncological outcomes. We advocate the VATS approach as a favored option for the resection of mediastinal malignancies.

Non-Neoplastic Mediastinal Cysts

Primary mediastinal cysts are infrequent lesions that can arise from a variety of mediastinal organs or structures. Most of these are congenital in origin and incidental findings during investigations for unrelated conditions. Histologically, the cysts may be composed of various tissues, including bronchogenic, pericardial, thymic, enteric, Müllerian, lymphatic, and parathyroid types. Mediastinal cysts typically demonstrate a benign clinical course and patients are cured after complete surgical resection. In this review, the embryogenesis, clinical, radiologic, and pathologic characteristics of non-neoplastic mediastinal cysts are examined with discussion of the role of immunohistochemistry and the most pertinent differential diagnosis.

The role of positron emission tomography/computed tomography in the evaluation of anterior mediastinal masses and differentiating between the histological subtypes of thymic epithelial neoplasms

Background

This study aims to investigate the role of positron emission tomography/computed tomography in differentiating between benign and malignant anterior mediastinal masses and between the histological subtypes of thymic epithelial neoplasms.

Methods

This retrospective study included a total of 57 patients (30 males, 27 females; mean age 48.9 years; range, 14 to 78 years) who underwent an fluorodeoxyglucose positron emission tomography/ computed tomography with an indication of an anterior mediastinal mass between May 2010 and November 2018. The maximum and mean standardized uptake values, metabolic tumor volume, total lesion glycolysis, and mean Hounsfield units of the lesions were determined. Thymic epithelial neoplasms were classified as low-risk thymomas (A, AB, B1), high-risk thymomas (B2, B3), and thymic carcinomas. All lesions were evaluated together and divided into two groups as benign and malignant, and positron emission tomography/computed tomography parameters of the two groups were compared.

Results

Histopathological examination identified 29 thymic epithelial neoplasms (13 low-risk, 14 high-risk, two thymic carcinomas), 13 benign lesions, and 15 malignant lesions. No significant correlation was identified between the positron emission tomography/computed tomography parameters and histological subtype of thymic epithelial neoplasms. There was no significant difference in the maximum and mean standardized uptake values, metabolic tumor volume, total lesion glycolysis, and mean Hounsfield units of the lesions between low-risk and high-risk thymic carcinomas. The maximum and mean standardized uptake values, metabolic tumor volume, and mean Hounsfield units of the lesions were significantly higher in the malignant group than in the benign group.

Conclusion

Our study results show that positron emission tomography/ computed tomography is useful in the differentiation of benign and malignant anterior mediastinal masses, although it fails to differentiate between the histological subtypes of thymic epithelial neoplasms.

Robot-assisted thoracoscopic surgery for mediastinal masses: a single-institution experience

Background

The objectives of this study were to evaluate the feasibility and safety of robot-assisted thoracic surgery (RATS) using the da Vinci robotic system for mediastinal mass resection and to describe the surgical approach for masses in different mediastinal regions.

Methods

We retrospectively reviewed data from 84 patients who underwent RATS for resection of a mediastinal mass from June 2015 to April 2019. The results were analyzed with descriptive statistics.

Results

The mediastinal mass was resected successfully in all patients, with one patient requiring conversion to conventional open surgery. There were no intraoperative complications. The most common diagnoses were thymoma (n=17), bronchogenic cyst (n=16), and schwannoma (n=12). The surgical approach was determined by the location of the lesion and the planned extent of surgical resection. Resection was performed in the lateral decubitus position in 29 patients with posterior mediastinal tumor, semi-lateral decubitus position in 42 patients who only need resection of anterior mediastinal mass, and reverse Trendelenburg position in 13 patients undergoing thymectomy. The mean (± standard deviation) operation time was 91.86±56.42 min, duration of chest tube use was 1.83±0.93 days, and postoperative hospital stay was 3.62±7.52 days. Three patients (3.5%) developed postoperative complications: one chylous fistula, which required reoperation, and one case each of atrial fibrillation and pulmonary infection, which were treated conservatively.

Conclusions

Our experience demonstrated that different surgical approaches of RATS are safe and feasible for mediastinal mass resection. An appropriate approach can be selected based on the mediastinal region in which the tumor is located.

Distribution of Mediastinal Lesions Across Multi-Institutional, International, Radiology Databases

INTRODUCTION

Mediastinal lesions are uncommon; studies on their distribution are, in general, small and from a single institution. Furthermore, these studies are usually based on pathology or surgical databases and, therefore, miss many lesions that did not undergo biopsy or resection. Our aim was to identify the distribution of lesions in the mediastinum in a large international, multi-institutional cohort.

METHODS

At each participating institution, a standardized retrospective radiology database search was performed for interpretations of computed tomography, positron emission tomography-computed tomography, and magnetic resonance imaging scans including any of the following terms: "mediastinal nodule," "mediastinal lesion," "mediastinal mass," or "mediastinal abnormality" (2011-2014). Standardized data were collected. Statistical analysis was performed.

RESULTS

Among 3308 cases, thymomas (27.8%), benign mediastinal cysts (20.0%), and lymphomas (16.1%) were most common. The distribution of lesions varied among mediastinal compartments; thymomas (38.3%), benign cysts (16.8%), and neurogenic tumors (53.9%) were the most common lesions in the prevascular, visceral, and paravertebral mediastinum, respectively (p < 0.001). Mediastinal compartment was associated with age; patients with paravertebral lesions were the youngest (p < 0.0001). Mediastinal lesions differed by continent or country, with benign cysts being the most common mediastinal lesions in the People's Republic of China, thymomas in Europe, and lymphomas in North America and Israel (p < 0.001). Benign cysts, thymic carcinomas, and metastases were more often seen in larger hospitals, whereas lymphomas and thymic hyperplasia occurred more often in smaller hospitals (p < 0.01).

CONCLUSIONS

Our study confirmed that the spectrum and frequency of mediastinal lesions depend on mediastinal compartment and age. This information provides helpful demographic data and is important when considering the differential diagnosis of a mediastinal lesion.

Optimal management of thymic malignancies: current perspectives

Thymic epithelial tumors (TETs) belong to orphan oncology. The incidence of TETs is about 1.3–3.2 cases per million worldwide. Following pathology, evolution and prognosis are variable. The World Health Organization classification distinguishes thymomas and thymic carcinomas. TETs are composed of thymic epithelial tumoral cells and normal lymphocytes. The mean age at diagnosis is 50–60 years-old. There are no identified risk factors. TETs are frequently associated with paraneoplastic syndromes as myasthenia gravis. The complete R₀ surgical resection is the most significant prognosis factor on survival. In 2010, the French National Institute of Cancer labeled the RYTHMIC network as a specific tumor board including thoracic surgeons, oncologist, and radiation therapist to define standard of care for the management of TETs. The aim of the review was to update knowledge to optimize the standard of care.