Mediastinum (Hong Kong, China)最新文献

This review article comprehensively examines the diagnostic approach to thymic epithelial tumors (TETs) and other mediastinal masses, focusing on imaging modalities and differential diagnosis. Beginning with a discussion on traditional and contemporary classification systems for mediastinal tumors, including the Japanese Association for Research on the Thymus (JART) and International Thymic Interest Group (ITMIG) classifications, it highlights the shift towards computed tomography (CT)-based categorizations. Emphasis is placed on the importance of distinguishing between solid and cystic lesions in the anterior mediastinum, with detailed insights into imaging characteristics and histological features of various TET subtypes such as thymomas, thymic carcinomas, and thymic neuroendocrine tumors (NETs). The review also elucidates common differential diagnoses, including lymphomas and germ cell tumors, providing guidance on key imaging findings and considerations for accurate diagnosis. Furthermore, it underscores the significance of patient background and blood tests in differential diagnosis, discussing age-related prevalence patterns and tumor marker assessment. After addressing the diagnostic challenges posed by thymic cysts offering insights into their radiological features, management considerations, and potential complications, this review extends to other rare mediastinal lesions highlighting the need for a comprehensive evaluation for accurate identification and management of these tumors. Finally, as illustrative examples, we present six cases highlighting various aspects of anterior mediastinal tumors, including TET. These cases provide valuable insights into the diagnostic challenges, imaging characteristics, and management considerations encountered in clinical practice. The cases presented herein do not all illustrate typical images, courses, and diagnoses. However, they each contain significant implications. Thus, we present them with the belief that they will aid in understanding the intricate nuances of image diagnosis in actual clinical practice.

Background and objective: Thymic carcinoma is an exceptionally rare cancer, with an annual incidence of just 0.15-0.29 per 100,000 people. Owing to its rarity, only few proven treatments have been developed. Understanding its genetic profile is crucial for the development of targeted therapies. However, limited studies have exclusively examined thymic carcinoma mutations, with most investigation combining thymomas and thymic carcinomas. This paper reviews findings from genetic studies focusing on thymic carcinoma alone and compares them to those of thymoma.

Methods: We conducted a PubMed search for relevant English studies on thymic carcinoma genomics. Then, key papers utilizing target sequencing or whole-exome sequencing were analyzed.

Key content and findings: The most frequently mutated genes were TP53, CDKN2A, CDKN2B, CYLD, KIT, TET2, SETD2, BAP1, and ASXL1. TP53 and CDKN2A are correlated with poor prognosis. CYLD, which regulates signaling related with proliferation and interacts with AIRE expression and T cell development, might predict the immunotherapy response. KIT mutations might enable targeted therapy. TET2, SETD2, BAP1, and ASXL1 regulate epigenetics, suggesting disruption of these mechanisms. Higher tumor mutational burden (TMB) and 16q loss distinguish thymic carcinoma from thymoma. Although some copy number aberrations are shared, thymic carcinoma exhibits a mutational profile distinct from that of thymoma.

Conclusions: Thymic carcinoma demonstrates a unique genomic landscape, suggesting a molecular pathogenesis distinct from that of thymoma. Our findings revealed prognostic biomarkers such as TP53/CDKN2A and potential therapeutic targets such as KIT. Because thymic carcinoma is extremely rare, sharing molecular profiling data could provide valuable insights into the molecular mechanisms driving the development of these tumors.

Thymic epithelial tumors (TETs), encompassing thymoma and thymic carcinoma, represent a rare and heterogeneous group of thoracic malignancies with varying prognoses and treatment strategies. Surgical resection is the cornerstone of therapy for localized stages, but the management of locally advanced or unresectable TETs often involves induction therapy, including chemotherapy and/or radiation therapy, as a neoadjuvant approach aimed at downstaging the tumor to facilitate subsequent resection. This review synthesizes current knowledge on the re-evaluation process and operative indications following induction therapy for TETs, highlighting the pivotal role of accurate assessment in guiding surgical decisions and optimizing patient outcomes. Induction therapy's efficacy is contingent upon precise re-evaluation methods to accurately gauge treatment response and assess resectability post-therapy. This review discusses the various modalities employed in re-evaluation, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT), and the significance of tumor markers, underlining their strengths and limitations. The adoption of modified RECIST criteria for TETs by the International Thymic Malignancy Interest Group (ITMIG) underscores the necessity for standardized assessment guidelines to ensure consistency and reliability across studies and clinical practices. Furthermore, we explore the implications of induction therapy on surgical decision-making, emphasizing the criteria for determining the suitability of patients for surgical intervention post-therapy. The review addresses the challenges and future perspectives associated with the re-evaluation process, including the potential for advanced imaging techniques and the integration of molecular and genetic markers to enhance the precision of treatment response assessment. In conclusion, the re-evaluation of TETs post-induction therapy is a complex but critical component of the multidisciplinary management approach for these patients. Standardizing re-evaluation methodologies and incorporating novel diagnostic tools could significantly improve the prognostication and treatment stratification, ultimately enhancing the therapeutic outcomes for patients with advanced TETs.

Background and objective: Thymic epithelial tumors (TETs) are rare and originate from the thymus. Thymomas and thymic carcinomas are the most common types of TETs. Of the two, thymomas tend to have a better prognosis and are typically localized, while thymic carcinomas have a worse prognosis and are more likely to spread. The Masaoka-Koga staging system is commonly used to determine the stage of TETs. Complete resection is the preferred treatment option, but treating locally advanced TETs can be challenging due to the invasion of surrounding structures. In such cases, induction therapy is administered to downstage the tumors and enable complete resection. We conducted this narrative review to evaluate the current progress in induction treatment for locally advanced TETs.

Methods: The literature search was performed using PubMed and Web of Science in June 2023. Prospective and retrospective published trials, systemic and narrative reviews, and meta-analyses were included.

Key content and findings: Induction chemotherapy is often used as a preoperative treatment for advanced TETs. Platinum and anthracycline-based chemotherapy regimens are commonly used for treating thymoma (response rate, 37-100%), and complete resection is highly common. Treatment with cisplatin and etoposide, carboplatin and paclitaxel, docetaxel and cisplatin have also demonstrated effectiveness, particularly in patients with thymic carcinoma or thymoma who cannot tolerate anthracycline regimens. The emergence of immunotherapy and targeted therapies may provide additional options for the treatment of TETs. Induction radiotherapy, as the sole treatment for TETs, is not widely practiced due to concerns about potential damage to surrounding tissues. However, combining modern radiation techniques with surgery has shown promising results in selected patients. Induction chemoradiotherapy, which combines chemotherapy and radiation, is an emerging approach for treating TETs. Despite the lack of randomized trials comparing chemotherapy with chemoradiotherapy, concurrent chemoradiation with radiation doses of 40-50 Gy is often considered the optimal induction therapy for thymic carcinoma patients or in more advanced special situations, such as great vessel invasion.

Conclusions: Overall, the optimal treatment for locally advanced TETs remains controversial. Induction therapy, including chemotherapy, radiotherapy, or chemoradiotherapy, is administered to downstage tumors and improve resectability. The choice of treatment depends on individual factors such as tumor stage, histology, and overall patient condition. However, further research and well-designed studies are needed to determine the most effective treatment strategies for locally advanced TETs.

Background and objective: Thymic epithelial tumors (TETs), including thymomas and thymic cancers, are relatively rare malignancies originating from the thymus. Although complete surgical resection is the cornerstone of treatment for these tumors, the optimal management strategy for locally advanced cases remains uncertain. Neoadjuvant therapies, with their potential to improve the likelihood of complete resection, are promising, particularly in marginally operable cases. However, the current evidence supporting this approach is lacking. This review of the existing literature on the efficacy of induction therapy followed by surgical resection for stage III or IV locally advanced TETs aimed to provide an up-to-date perspective and highlighting directions for future clinical research.

Methods: PubMed was searched using the keywords "surgery," "survival", "thymoma", "thymic cancer", and "induction therapy". Relevant articles including case series, retrospective studies, prospective studies, and review articles were reviewed and selected for this comprehensive narrative review.

Key content and findings: This review included primarily revealed retrospective studies and a limited number of prospective phase II trials on induction therapy followed by surgery for stage III or IV locally advanced TETs. No randomized phase III studies were identified, indicating that a comprehensive evaluation of the benefits of induction therapy on overall survival (OS) has not yet been conducted. Induction therapies for both invasive thymoma and thymic cancer included chemotherapy, radiotherapy, and chemoradiotherapy, with anthracycline-based combination chemotherapies being the primary option. For exclusively invasive thymomas, the median rate of complete surgical resection and the 5-year OS rate were reported as 76% and 85%, respectively. Literature focusing on induction therapy for TETs, which includes both thymoma and thymic cancers, indicates that the rates of complete resection and 5-year OS are 76% and 70%, respectively.

Conclusions: Our narrative review of retrospective and prospective studies highlighted promising long-term OS rates in patients with advanced TETs who underwent induction therapy followed by surgical resection. These findings support this multimodal treatment strategy in selected patients with stage III and IV TETs.

Background and objective: Thymic epithelial tumors (TETs), including thymomas and thymic carcinomas, are rare mediastinal tumors. Surgical resection is the treatment strategy for resectable TETs, and postoperative radiotherapy (PORT) is administered to improve local control in patients with a high risk of recurrence. The rarity of TETs has led to a lack of randomized controlled trials, and the current indications for PORT rely largely on retrospective studies. This review analyzes the literature on TETs, highlighting PORT, to guide current research and future investigations.

Methods: Studies that focused on TETs, addressed topics on PORT, and had English abstracts accessible online were eligible for inclusion in our review. We excluded case reports or review articles, articles written in languages other than English, articles published >30 years ago, and articles concerning thymic neuroendocrine tumors.

Key content and findings: Masaoka or Masaoka-Koga staging, World Health Organization (WHO) histological subtype, and resection status indicate PORT in resected TETs. Current literature suggests that PORT does not improve overall survival in stage I-IIA TETs, with inconsistent results for stage IIB-III TETs. Patients with a higher risk, such as carcinomas or WHO type B, might benefit from PORT if they do not develop distant metastasis. Determining which patients will benefit most from PORT requires further investigation. For recurrent TETs, the significance of applying PORT is unclear because available data are limited. Given the long-term survival of TETs, late toxicities, including radiation pneumonitis, radiation-induced cardiotoxicities, and secondary malignancies, must be addressed. Proton beam radiotherapy might reduce toxicities by sparing organs at risk compared to conventional photon beam radiotherapy. The use of high-precision radiation therapy, along with emerging immunotherapy, targeted therapy, and minimally invasive surgery, could improve TET outcomes.

Conclusions: This review consolidates the literature on PORT for TETs, factoring in the Masaoka-Koga staging, WHO histological subtypes, and resection status. Varying results regarding PORT efficacy have led to an undefined strategy for stage IIB-III TETs. Although advanced radiotherapy techniques promise to reduce radiation-induced toxicities, further research is needed to investigate the efficacy of PORT and combination therapy.

Locally invasive thymic neoplasms are challenging clinical scenarios and typically require a multidisciplinary approach. The involvement of major mediastinal veins such as the superior vena cava (SVC) used to be a contraindication to surgery, but with improved surgical technique and outcomes, this paradigm has shifted. In some situations, complex resections and reconstructions may be indicated and required to improve the long-term outcome of these patients. We report two of our cases along with a current review of literature. We also describe the preoperative workup, operative techniques, postoperative management, complications, and outcomes of patients with invasive thymic neoplasms that involve the mediastinal veins. Our first case describes a patient who was diagnosed with a thymoma extending from the diaphragm to the base of the neck that was also encasing major vascular structures including the SVC and left innominate vein. Our second case describes a patient who was also diagnosed with a large anterior mediastinal mass encasing the great veins and invading the chest wall. We describe the management of these patients and then delve deeper into operative techniques including SVC resection and reconstruction. We describe the types of conduits that can be used and complications to be mindful of when clamping the great veins, such as the SVC. Improvements in conduit materials and neoadjuvant and adjuvant therapies over the years have made it more feasible for patients with invasive thymic neoplasms to undergo surgery.

Background: Descending necrotizing mediastinitis (DNM) is an acute life-threatening infection that originates in the oropharyngeal region. It is an uncommon disease with a mortality rate of about 20-40%. This high mortality is mainly attributed to delays in diagnosis and treatment and poor drainage of the mediastinum. We highlight key points that may help reduce mortality.

Case description: We analyze a retrospective case series of seven patients diagnosed with DNM between March 2019 and July 2022 at Hospital de la Santa Creu i Sant Pau. The primary oropharyngeal infection was peritonsillar abscess in three cases and odontogenic abscess in four. All patients showed symptoms of severe cervical infection and symptoms suggestive of mediastinitis. A cervicothoracic computed tomography (CT) scan confirmed the presence of cervical and mediastinal collections and emphysema in all cases. All patients were simultaneously evaluated by the otorhinolaryngology and thoracic surgery teams. Broad-spectrum antibiotic therapy was instituted pending culture. All the patients underwent urgent surgery, consisting of cervicotomy to control the cervical focus and unilateral or bilateral video-assisted thoracoscopic debridement and drain of the pleural cavities and mediastinum. Regarding the outcomes, no patients died, one patient (14.2%) underwent transcervical mediastino-thoracoscopy drainage only. In six patients (85.8%) we performed a combined transcervical and transthoracic approach. Reoperation was required in 3 (43%) cases. The parameter that indicated a poor clinical evolution in these patients was an increase in C-reactive protein and the infection extension on the cervicothoracic CT scan. The follow-up was 30 days from last surgery; there were no losses.

Conclusions: Based on our experience, the key points that can help reduce the high mortality associated with DNM are a rapid multidisciplinary assessment and a combined surgical procedure, considering the minimally invasive approach as the first option to drain the pleural cavities and mediastinum.