Metaplastic thymoma in the middle mediastinum: a rare case report and surgical treatment analysis of a 32-year-old female patient.

Background: Metaplastic thymoma (MT), an exceedingly rare variant of primary thymic epithelial neoplasms, is distinguished by its indolent progression and unique histopathological profile. It presents a biphasic pattern characterized by solid epithelial and spindle cell components, potentially leading to diagnostic confusion with type A thymomas or the type A component of type AB thymomas. Accurate diagnosis is pivotal for optimal therapeutic strategies and prognostication. Case Description: We document an exceptional case of a 32-year-old woman, incidentally discovered to have a mediastinal nodule in the middle compartment on chest computed tomography (CT). The lesion was excised via video-assisted thoracoscopic surgery. Histological evaluation revealed a biphasic cellular architecture comprising epithelioid and spindle cells. Immunohistochemical analysis demonstrated significant positivity for CK5/6 and P40 in epithelial cells, and vimentin and epithelial membrane antigen in spindle cells, with a low proliferation index marked by Ki-67. Noteworthy, fluorescence in situ hybridization (FISH) analysis identified a YAP1::MAML2 gene fusion, with a predominant pattern suggestive of fusion gene presence, thus corroborating the diagnosis of MT. Conclusions: This report underscores the critical role of a multifaceted diagnostic approach, including histopathological, immunohistochemical, and genetic analyses, in the identification of MT. The detection of the YAP1::MAML2 gene fusion through FISH analysis provides a robust diagnostic marker, highlighting the necessity for clinical and pathological vigilance for this rare tumor.

Primary mucinous adenocarcinoma of the anterior mediastinum with HER-2 mutation: A rare case report.

We report the case of a 68-year-old male whose Computed Tomography (CT) scan presented a mass (68*62*54 mm) of the right anterior mediastinal and pathologically diagnosis was mucinous adenocarcinoma(MA). The peripheral vessels are surrounded by the big mass in the anterior mediastinum which was associated with multiple metastases, thus we performed palliative chemoradiotherapy and we tried Human Epidermal Growth Factor Receptor-2 (HER-2) inhibitors based on the Next Generation Sequencing. The patient passed away 16 months after the onset of the disease. In this report, we review the rare case of anterior mediastinum MA as well as perspectives for potential future treatments.

Prevalence and quantity of lymph nodes at mediastinal stations in patients with lung cancer: lessons from 181 bilateral mediastinal lymphadenectomies.

BACKGROUND: This study evaluated the prevalence and quantity of lymph nodes at particular stations of the mediastinum in patients with lung cancer. These data are important to radiologists, pathologists, and thoracic surgeons because they can serve as a benchmark when assessing the completeness of lymph node dissection. However, relevant data in the literature are scarce. METHODS: Data regarding the number of lymph nodes derived from two randomised trials of bilateral mediastinal lymph node dissection, the BML-1 and BML-2 study, were included in this analysis. Detectable nodes at particular stations of the mediastinum and the number of nodes at these stations were analysed. RESULTS: The mean number of removed nodes was 28.67 (range, 4-88). Detectable lymph nodes were present at stations 2R, 4R, and 7 in 93%, 98%, and 99% of patients, respectively. Nodes were rarely present at stations 9 L (33%), and 3 (35%). The largest number of nodes was observed at stations 7 and 4R (mean, 5 nodes). CONCLUSION: The number of mediastinal lymph nodes in patients with lung cancer may be greater than that in healthy individuals. Lymph nodes were observed at stations 2R, 4R, and 7 in more than 90% of patients with lung cancer. The largest number of nodes was observed at stations 4R and 7. Detectable nodes were rarely observed at stations 3 and 9 L. TRIAL REGISTRATION: ISRCTN 86,637,908.

Quantitative assessment of cardiac 123iodo-metaiodobenzylguanidine SPECT/CT in patients with arrhythmogenic right ventricular cardiomyopathy: Novel insight in disease monitoring.

BACKGROUND: The heart-to-mediastinum ratio (H/M-Ratio) of 123iodo-metaiodobenzylguanidine (123I-MIBG) represents state-of-the-art assessment for sympathetic dysfunction in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to evaluate quantitative reconstruction of 123I-MIBG uptake and to demonstrate its correlation with echocardiographic parameters. METHODS: Cardiac innervation was assessed in 23 patients diagnosed with definite ARVC or borderline ARVC and 12 patients with other cardiac disease presenting arrhythmia, using quantitative 123I-MIBG Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) imaging. Tracer uptake was evaluated in the left (LV) and right ventricle (RV) based on a CT scan after quantitative image reconstruction. The relationship between tracer uptake and echocardiographic parameter data was examined. RESULTS: Absolute quantification of 123I-MIBG uptake in the LV and RV is feasible and correlates accurately with the gold standard H/M Ratio. When comparing sensitivity and specificity, the area under the curve (AUC) favors standardized uptake value (SUV) of the RV over the right-ventricle-to-mediastinum-ratio (RV/M-Ratio) for diagnosing ARVC. A reduced RV-SUV in patients with definite ARVC is associated with reduced RV function. RV polar maps revealed globally reduced 123I-MIBG uptake without segment-specific reduction in the RV. CONCLUSIONS: Quantitative 123I-MIBG SPECT in ARCV patients offers robust potential for clinical reporting and demonstrates a significant correlation with RV function. Segmental RV analysis needs to be evaluated in larger samples. In summary, cardiac 123I-MIBG imaging using SUV could facilitate image-guided therapy in patients diagnosed with ARVC.

Prediction of metastases in confusing mediastinal lymph nodes based on flourine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging using machine learning.

Background: For patient management and prognosis, accurate assessment of mediastinal lymph node (LN) status is essential. This study aimed to use machine learning approaches to assess the status of confusing LNs in the mediastinum using positron emission tomography/computed tomography (PET/CT) images; the results were then compared with the diagnostic conclusions of nuclear medicine physicians. Methods: A total of 509 confusing mediastinal LNs that had undergone pathological assessment or follow-up from 320 patients from three centres were retrospectively included in the study. LNs from centres I and II were randomised into a training cohort (N=324) and an internal validation cohort (N=81), while those from centre III patients formed an external validation cohort (N=104). Various parameters measured from PET and CT images and extracted radiomics and deep learning features were used to construct PET/CT-parameter, radiomics, and deep learning models, respectively. Model performance was compared with the diagnostic results of nuclear medicine physicians using the area under the curve (AUC), sensitivity, specificity, and decision curve analysis (DCA). Results: The coupled model of gradient boosting decision tree-logistic regression (GBDT-LR) incorporating radiomic features showed AUCs of 92.2% [95% confidence interval (CI), 0.890-0.953], 84.6% (95% CI, 0.761-0.930) and 84.6% (95% CI, 0.770-0.922) across the three cohorts. It significantly outperformed the deep learning model, the parametric PET/CT model and the physician's diagnosis. DCA demonstrated the clinical usefulness of the GBDT-LR model. Conclusions: The presented GBDT-LR model performed well in evaluating confusing mediastinal LNs in both internal and external validation sets. It not only crossed radiometric features but also avoided overfitting.

Cardiac sympathetic activity and lethal arrhythmic events: insight into bell-shaped relationship between 123I-meta-iodobenzylguanidine activity and event rates.

BACKGROUND: 123I-meta-iodobenzylguanidine (mIBG) has been applied to patients with chronic heart failure (CHF). However, the relationship between 123I-mIBG activity and lethal arrhythmic events (ArE) is not well defined. This study aimed to determine this relationship in Japanese and European cohorts. RESULTS: We calculated heart-to-mediastinum (H/M) count ratios and washout rates (WRs) of 827 patients using planar 123I-mIBG imaging. We defined ArEs as sudden cardiac death, arrhythmic death, and potentially lethal events such as sustained ventricular tachycardia, cardiac arrest with resuscitation, and appropriate implantable cardioverter defibrillator (ICD) discharge, either from a single ICD or as part of a cardiac resynchronization therapy device (CRTD). We analyzed the incidence of ArE with respect to H/M ratios, WRs and New York Heart Association (NYHA) functional classes among Japanese (J; n = 581) and European (E; n = 246) cohorts. We also simulated ArE rates versus H/M ratios under specific conditions using a machine-learning model incorporating 13 clinical variables. Consecutive patients with CHF were selected in group J, whereas group E comprised candidates for cardiac electronic devices. Groups J and E mostly comprised patients with NYHA functional classes I/II (95%) and II/III (91%), respectively, and 21% and 72% were respectively implanted with ICD/CRTD devices. The ArE rate increased with lower H/M ratios in group J, but the relationship was bell-shaped, with a high ArE rate within the intermediate H/M range, in group E. This bell-shaped curve was also evident in patients with NYHA classes II/III in the combined J and E groups, particularly in those with a high (> 15%) mIBG WR and with ischemic, but not in those with non-ischemic etiologies. Machine learning-based prediction of ArE risk aligned with these findings, indicating a bell-shaped curve in NYHA class II/III but not in class I. CONCLUSIONS: The relationship between cardiac 123I-mIBG activity and lethal arrhythmic events is influenced by the background of patients. The bell-shaped relationship in NYHA classes II/III, high WR, and ischemic etiology likely aids in identifying patients at high risk for ArEs.

Ectopic Thyroid Tissue in the Anterior Mediastinum: A Case Report.

Ectopic thyroid tissue (ETT) is a rare finding on mediastinoscopy which could be attributed to a defect early in thyroid gland embryogenesis, as the glandular tissue makes its way to a pre-tracheal position. The more distal the location of the ectopic tissue from typically neighboring structures, such as the recurrent laryngeal nerves or the superior thyroid artery, the greater the likelihood for issues such as hyperthyroidism, compression of nearby neurovascular structures, and malignancy. Depending on the exact anatomical location and hormonal activity of the tissue, management can range from administration of iodine to surgical resection. This report discusses a case of ETT discovered during the resection of an anterior mediastinal mass, possible treatment, and management plans.

Dedifferentiated Mediastinal Liposarcoma: A Case Report.

Liposarcoma is the most common soft tissue sarcoma type in adults, originating mainly from the retroperitoneum and lower extremities. Mediastinal liposarcomas constitute an extremely rare clinical entity of mesenchymal origin. Among subtypes, dedifferentiated liposarcoma is characterized by poor survival, but little is known about its biological behavior. We present the case of a 78-year-old male patient who presented with vague symptoms, predominantly dyspnea and chest pain. Imaging revealed a large mediastinal mass and surgical resection was performed in a piecemeal manner due to the inability to achieve a microscopically negative surgical margin (R0 resection) for the residual tumor. Histological examination confirmed the diagnosis of dedifferentiated liposarcoma. The patient's postoperative course was uneventful, with discharge from the hospital on the 10th postoperative day. However, local recurrence was detected after two months and the patient died four months after the operation. The present case report highlights the importance of radical excision for the prevention of local recurrence and the presentation of histological characteristics of this tumor. Radical surgical resection remains the fundamental treatment, while chemo and radiotherapy may have an adjuvant role. In cases of inability to obtain negative margins, surgical debulking can offer symptomatic relief.

Recognition of an extralobar pulmonary sequestration during lung resection.

BACKGROUND: Extralobar pulmonary sequestration is located outside the lung parenchyma and is covered by a separated pleural sac, which comprises approximately 25% of all pulmonary sequestration. CASE PRESENTATION: This article reported one case of an extralobar pulmonary sequestration originated from the mesoesophagus, which was recognized and excised during a lung resection. Histologic examination revealed an ectopic lung tissue with hyperplasia of bronchioles, which was accord with an extralobar pulmonary sequestration. CONCLUSIONS: CT angiogram, ultrasound and MRI can be used to clarify the diagnosis and detect the abnormal feeding arteries of extralobar pulmonary sequestration. Carefulness should be taken while dissecting and ligating the potential feeding arteries. Endovascular occlusion might be an alternative option to surgery.

Teratoma to Angiosarcoma: A Metamorphosis in the Mediastinum.

We describe a rare and remarkable transformation of an immature mediastinal teratoma into high-grade angiosarcoma in a 21-year-old male. Mediastinal teratomas, particularly immature ones, are exceedingly rare, representing a small fraction of germ cell tumors (GCTs). Our case describes the clinical journey of the patient, who initially presented with acute chest pain and was subsequently diagnosed with an immature teratoma following imaging studies and elevated tumor markers. Despite an initial positive response to cisplatin-based chemotherapy, surveillance imaging revealed liver masses, which a biopsy confirmed as angiosarcoma. This transformation underscores the aggressive nature of immature teratomas and the propensity for sarcomatous differentiation, particularly in the mediastinum. The case contributes valuable insight into the management and surveillance of mediastinal non-seminoma germ cell tumors (MNGCT), a subset of GCTs with limited literature. We believe this case is the first in the literature to describe a transformation from an immature teratoma in the mediastinum to a high-grade angiosarcoma.

Metastatic right atrial mass in the presence of atrial septal defect: A rare clinical coincidence.

Key Clinical Message: The key takeaway from this clinical scenario is to choose the most appropriate and reasonable treatment plan when dealing with a patient who has atrial septal defect (ASD) and concurrent atrial and mediastinal masses. In such cases, a heart-oncology team should make the therapeutic decision. Abstract: Right atrial masses are not pretty rare and might be a diagnostic challenge. Thrombosis, tumors, and vegetations are primary differential diagnoses. Workup for these masses usually includes multimodality imaging and biopsy in selected cases. We report a case of a 37-year-old lady who presented with cough, dyspnea, and head and neck swelling after a cesarean section. Echocardiography revealed a right atrial mass accompanied by a secundum type atrial septal defect (ASD). Pulmonary CT Angiography was performed, in which a lobulated mass in the anterior mediastinum was detected, and a heart-oncology team made the therapeutic decision. The patient was scheduled for surgical ASD closure and concomitant tissue biopsy. The pathology results were in favor of poorly differentiated germ cell tumors, and chemotherapy was started following the surgery. After two sessions of chemotherapy, the tumor did not respond to the primary regimen. Thus, an updated regimen was initiated. Compliance with the updated regimen was acceptable, and the patient is currently under treatment and follow-up.

Endobronchial ultrasound-guided transbronchial fine needle aspiration of mediastinal lymphadenopathy: Diagnostic performance and clinical implications of the World Health Organization reporting system.

INTRODUCTION: Lymph node fine-needle aspiration cytology (LN-FNAC) is a common, rapid, minimally invasive and cost-effective diagnostic method. For mediastinal lymph nodes, endobronchial ultrasound (EBUS) guided LN-FNAC is a first-line investigation and has an indispensable role in the diagnosis and staging of patients with suspected lung cancer. Recently, a new WHO system has been proposed for classification of LN-FNAC heralding five different diagnostic categories; insufficient, benign, atypical, suspicious for malignancy and malignant. The aim of this study was to evaluate the diagnostic accuracy and risk of malignancy (ROM) of these categories in EBUS-guided LN-FNAC from mediastinal lymph nodes. METHOD: We evaluated 2110 consecutive mediastinal lymph nodes during this one-year retrospective study. Corresponding radiological images and histologic material were used as ground truth to calculate accuracy, sensitivity, specificity and ROM. RESULTS: The WHO system showed an overall accuracy of 93.7% with a sensitivity of 83.0% and a specificity of 97.5%. The positive predictive value was 92.3% and the negative predictive value 94.2%. The overall ROM for each category in the WHO classification system was 12.8% for the inadequate, 2.4% for the benign, 47.4% for the atypical, 81.0% for the suspicious for malignancy and 93.6% for the malignant category. CONCLUSION: The results of the present study indicate that the new WHO system entails a high diagnostic accuracy regarding EBUS-guided LN-FNAC assessment of mediastinal lymph nodes and supports its integration into clinical practice. Application of the WHO system standardizes risk assessment thus facilitating communication between cytopathologists and clinicians and minimizes the need for histopathological analysis.

Primary mediastinal seminoma with azoospermia: case report and review of the literature.

Introduction: Since the first report, primary mediastinal seminoma has a low incidence in the population, and it mainly affects young and middle-aged men, is clinically rare, and accounts for a very small proportion of mediastinal tumors. In this study, we describe the first case of primary mediastinal seminoma with azoospermia and hypothesize that the coexistence of the two disorders may not be a coincidence. Case report: A 16-year-old man presented with chest tightness and chest pain, a mediastinal mass on chest CT, and abnormal 18F-fluoro-deoxyglucose uptake on a PET-CT scan. By biopsy of the mass, the pathological diagnosis was a primary mediastinal seminoma. Because chemotherapy is included in the treatment of the tumor, the patient underwent sperm freezing before treatment, considering that chemotherapy can affect fertility, but the patient was diagnosed with azoospermia. Finally, the patient underwent tumor resection and postoperative chemotherapy. No tumor recurrence was observed at the current follow-up. Conclusion: Primary mediastinal seminoma is mainly confirmed by histopathological examination, and surgery and chemoradiotherapy are the current treatments. In patients with mediastinal seminoma or azoospermia, doctors should be aware that the two disorders may coexist, especially in men who have fertility requirements or long-term infertility, and that examination of the mediastinum and semen may lead to unexpected findings in the diagnosis and treatment. For mediastinal germ cell tumors, genetic testing is of great value in the treatment of tumors and the prediction of associated diseases. Future studies exploring the potential correlation between mediastinal seminoma and azoospermia will be prospective.

A Rare Case of Cervico-Mediastinal Thyroid Teratoma.

Teratomas are rare germ cell tumors derived from multiple germinal cell layers. Thyroid teratomas, specifically, are exceptionally uncommon and present unique diagnostic and therapeutic challenges. Here, we report a case of cervico-mediastinal thyroid teratoma, highlighting diagnostic difficulties and surgical management. A 37-year-old woman presented with right lateral cervical swelling, leading to radiological imaging suggesting a thymic teratoma. However, cytology indicated a colloid cyst. Surgical removal was performed, revealing a mixed-type teratoma originating from the thyroid gland. Thyroid teratomas pose diagnostic and therapeutic challenges due to their rarity and complex nature. Further research is needed to establish standardized guidelines for their management.

Gastropericardial fistula: A successfully operated heart code.

Gastropericardial fistula is a rare, extremely serious and life-threatening condition. Its most common aetiology is secondary to iatrogenic injury following gastric surgery. Clinical manifestations may be non-specific with precordial pain, simulating an acute coronary syndrome, and may be accompanied by electrocardiogram abnormalities. Diagnosis is made by thoracoabdominal computed tomography (CT) with oral and intravenous contrast. Treatment is surgical and consists of repair of the anomalous communication. We present the case of an 81-year-old male patient with gastropericardial fistula who underwent surgery, with the aim of reviewing the diagnosis and the appropriate therapeutic strategy.

A pancreatic pseudocyst sitting in the mediastinum-A case report of an unusual occurrence.

Pancreatitis can produce several complications such as pseudocyst, which can happen in acute and chronic pancreatitides. Pseudocysts are typically found in the abdomen but can rarely extend into the mediastinum. Atypical symptoms such as dyspnea, dysphagia, coughing, vomiting, abdominal or chest pain, and hemoptysis are usually the notable complaints. CT scan, MRI, and endoscopic ultrasound are valuable diagnostic modalities. Drainage and surgical removal of the pseudocyst are the treatment options. Herein, we outline the case of a young female with episodic chest and epigastric discomfort, dysphagia, and weight loss. Previously, she was incorrectly diagnosed with gastroesophageal reflux disease and peptic ulcer. A mediastinal pseudocyst secondary to chronic pancreatitis was found to be the cause. The patient underwent surgical removal of the pseudocyst and a pancreaticojejunostomy. Significant improvement was noticed at follow-up. This article highlights the possibility of such unusual conditions and the importance of a proper assessment while treating patients with epigastric pain.

Surgical access to the mediastinum-all roads lead to Rome: a literature review.

Background and Objective: The mediastinum is a complex, heterogeneous area, which leads vertically across the thoracic cavity between the bilateral mediastinal pleurae, connecting the head and neck region with the thoracic cavity. Different classifications have been published to differentiate between the so-called mediastinal compartments while the most used classification surely is the 4-compartments Gray`s classification, dividing it into the superior, anterior, middle and posterior mediastinum. Mediastinal abnormalities include infections (mediastinitis) and solid or cystic mediastinal masses. These masses can be divided into benign and malignant lesions originating from mediastinal structures/organs or represent manifestations of metastatic disease, often metastatic non-small cell lung cancer (NSCLC). This review aims to explore the different mediastinal pathologies along with indications and surgical approaches. Methods: We performed literature research in PubMed, MEDLINE, Embase, CENTRAL, and CINAHL databases. Only papers written in English were included. Key Content and Findings: Depending on the indication for surgical intervention and the localization of the pathology, surgical approach may differ immensely. Mediastinal staging of lung cancer, primary lesions of the mediastinum, mediastinitis and traumatic mediastinal injuries display the most frequent indications for mediastinal surgery. Surgical approaches trend towards minimally invasive, video- or robotic-assisted techniques and are becoming increasingly refined to adapt to the special characteristics of the mediastinum. However, certain indications still require open access for best possible mediastinal exposure or oncological reasons. Conclusions: To guide optimal surgical approach selection to the mediastinum, the following overview will present all published surgical approaches to the mediastinum and discuss their practical relevance and indications aiming to help surgeons in the management of patients with mediastinal pathologies who should undergo surgery.

Giant cell tumor of the posterior arc of the rib: A case report and literature of review.

INTRODUCTION AND IMPORTANCE: Giant cell tumors of bone (GCTB) are infrequent tumors that usually impact the epiphyses of long bones and uncommonly manifest in the ribs. Herein, we report a case of asymptomatic GCTB directly invading the lung tissue. CASE PRESENTATION: A 36-year-old man was referred to our emergency department with only left chest pain. Computed tomography revealed a large heterogeneous solid cystic mass in the left lung apex and amorphous calcification and distraction in the posterior part of the left fourth rib. Histological examination also exhibited that the GCTB originated from the rib. The patient underwent an en-bloc resection with no recurrence in his one-year follow-up. CLINICAL DISCUSSION: GCTB is characterized by osteoclast-like multinucleated giant cells and can exhibit aggressive local behavior. GCTB in the rib is rare, mainly found in the posterior arc. Radiographic features include lytic lesions with bone remodeling, often seen eccentrically in long bone epiphyses. Aggressive tumors may show cortical destruction and soft tissue extension. Surgery is often recommended for GCTB management, aiming for complete resection with sufficient surgical margins. CONCLUSION: The absence of well-defined diagnostic criteria hinders the accurate diagnosis of GCTB, making a comprehensive assessment through radiological and histological examinations crucial. Upon physical examination, GCTB should be considered in the differential diagnosis for mediastinal lesions, regardless of their size. Furthermore, surgical removal can be taken into account as the primary treatment strategy for tumors that originate from the posterior arc of the ribs, such as GCTB.