UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: Mediastinal tumors, particularly non-neuroendocrine thymic epithelial tumors (TET) are relatively uncommon, posing challenges for extensive epidemiological studies. This study presents a comprehensive analysis of these tumors in the United States (US) and Germany (GER) from 1999 to 2019.
UNASSIGNED: Patients aged 0-19 (n=478) and ≥20 years (n=17,459) diagnosed with malignant tumors of the anterior mediastinum were identified from the Surveillance, Epidemiology, and End Results registry (SEER) and the Zentrum für Krebsregisterdaten (ZfKD) databases.
UNASSIGNED: Among patients aged ≥20 years, TETs accounted for the most prevalent anterior mediastinal tumors (US/GER: 63%/64%), followed by lymphomas (14%/8%). For patients <20 years, predominant tumors included germ cell tumors (42%/14%), lymphomas (38%/53%), and TETs (10%/27%). The overall annual incidence of thymoma was 2.2/2.64 (US/GER) per million inhabitants and for thymic carcinomas 0.48/0.42. The male-to-female ratio was 1:1.09/1.03, and the mean age 59.48 ± 14.89/61.33 ± 13.94. Individuals with thymomas, but not thymic carcinomas, exhibited a 21%/29% significantly heightened risk of developing secondary malignancies compared to controls with non-thymic primary tumors.
UNASSIGNED: This study provides a comparative analysis of anterior mediastinal tumors, particularly TETs, in the US and GER over the past two decades. Furthermore, it highlights a significantly elevated incidence of secondary malignancies in thymoma patients.

BACKGROUND: Thymic carcinoma is a rare disease with an incidence of around 0.5 cases per million with a poor prognosis. The aim of this study was to assess patient outcomes with advanced thymic carcinoma receiving first-line chemotherapy.
METHODS: In our retrospective cohort study, we included patients who underwent treatment for metastatic thymic carcinoma between January 2013 to December 2019 in our hospital. Overall survival, progression-free survival (PFS), objective response rates (ORR) and chemotherapy regimens were assessed and analyzed.
RESULTS: A total of 27 patients were retrospectively analyzed. All patients received a platinum (cisplatin or carboplatin) based regimen as first-line chemotherapy (29.6% received ADOC, 11.1% received PE, 40.7% received CP, 14.8% received CAP). The median PFS on first-line chemotherapy was 199 days. The response rate was 40.7%. Median overall survival (OS) was 585 days. Positive CD5 staining was associated with better PFS.
CONCLUSIONS: We highlight the critical role of platinum-based chemotherapy agents as a primary treatment modality in advanced thymic carcinoma, underscoring the efficacy of platinum as a first-line option for recurrent disease, even in cases previously treated with platinum. Additionally, our findings indicate that CD5 positivity could be associated with improved PFS, suggesting its potential as a prognostic marker.

Multilocular thymic cysts (MTC) are acquired multilocular cysts caused by inflammation. The rarity of such lesions and a lack of recognition make diagnosis and treatment difficult. Herein, we present our experience with a multilocular mediastinal cyst that resulted in the development of thymic cancer with metastasis over a period of 13 years. Computed tomography findings revealed an anterior mediastinal mass that was suspected to be an MTC in a 49-year-old man. The mass shrank gradually over a period of 7 years; however, growth was observed at 10 years after initial detection. At 13 years after detection, thymic carcinoma with multiple lung metastases was diagnosed. Resection was recommended during the follow-up period, but the patient refused treatment. A multilocular wall and location are factors that indicate MTC. However, even if a definitive diagnosis is not made, resection of multilocular anterior mediastinal cysts should be considered as determining the preoperative diagnosis is difficult. Nevertheless, our case suggests that the coexistence of tumors with cysts is possible, and the potential for malignant tumor development exists.

BACKGROUND: To assess the feasibility of the cine MR feature tracking technique for the evaluation of cardiovascular-induced morphological deformation in the diagnosis of thymic epithelial tumors (TETs).
METHODS: Our study population consisted of 43 patients with pathologically proven TETs including 10 low-grade thymomas, 23 high-grade thymomas, and 10 thymic carcinomas. Cine MR images were acquired using a balanced steady-state free precession sequence with short periods of breath-hold in the axial and oblique planes in the slice with the largest lesion cross-sectional area. The tumor margin was manually delineated in the diastolic phase and was automatically tracked for all other cardiac phases. The change rates of the long-to-short diameter ratio (∆LSR) and tumor area (∆area) associated with pulsation were compared between the three pathological groups using the Kruskal-Wallis H test and the Mann-Whitney U test. A receiver-operating characteristic (ROC) curve analysis was performed to assess the ability of each parameter to differentiate thymic carcinomas from thymomas.
RESULTS: ∆LSR and ∆area were significantly different among the three groups in the axial plane (p = 0.028 and 0.006, respectively) and in the oblique plane (p = 0.034 and 0.043, respectively). ∆LSR and ∆area values were significantly lower in thymic carcinomas than in thymomas in the axial plane (for both, p = 0.012) and in the oblique plane (p = 0.015 and 0.011, respectively). The area under the ROC curves for ∆LSR and ∆area for the diagnosis of thymic carcinoma ranged from 0.755 to 0.764.
CONCLUSIONS: Evaluation of morphological deformation using cine-MR feature tracking analysis can help diagnose histopathological subtypes of TETs and identify thymic carcinomas preoperatively.

We herein report two cases of thymic cancer with Lynch syndrome showing a high frequency of microsatellite instability and loss of mismatch repair protein expression without MLH1 promoter hyper-methylation. In Case 1, a 71-year-old man had a pathogenic germline variant in MLH1 and underwent tumor resection. No relapse has been reported thus far. In Case 2, a 43-year-old man underwent genetic testing that also showed a pathogenic germline variant in MLH1. Since these two cases had MLH variants, we suspect a possible association between thymic cancer with Lynch syndrome and germline pathogenic variants in MLH1.

OBJECTIVE: Thymic epithelial neoplasms (TEN) represent a heterogeneous group of rare thoracic malignancies. We analyzed the clinicopathological features, survival outcomes, risk factors, and patterns of recurrence in patients undergoing resection.
METHODS: Records were reviewed for adult patients with TEN who underwent resection from 2006-2019. Survival rates were assessed using the Kaplan-Meier method. Univariable and multivariable analyses were performed using the log-rank test and Cox proportional hazards model.
RESULTS: A total of 100 patients were analyzed (51 females, median age 58 years). Thymoma was the most common histology (n = 92), followed by thymic carcinoma (n = 5), and thymic NET (neuroendocrine tumor) (n = 3). Stage II (Masaoka) tumours were most common (n = 51), followed by stage I (n = 27). WHO B2/B3 was the most prominent histological subtype (n = 34). Complete resection (R0) was achieved in 91 patients: 86/92 thymoma, 4/5 thymic carcinoma and 1/3 NET. The most common treatment modality was surgery alone in 72 patients, followed by surgery and radiation therapy in 24, and adjuvant chemoradiotherapy in 3 patients. Only one patient with thymic carcinoma received neoadjuvant chemotherapy. The 10-year overall and disease-free survival rates were 86.6% and 83.9%, respectively. Recurrence was most common in NETs (3/3). Risk factors for recurrence identified on multivariable analyses were: R1/2 resection (HR 9.30, 95%CI 1.82-36.1), TEN subtype (HR 8.08, 95%CI 1.24-34.6), and presence of lymphovascular invasion (LVI) (HR 9.56, 95%CI 2.56-25.8).
CONCLUSIONS: Complete resection remains critical in patients with TEN. Incomplete resection, high-risk histology and LVI highlight the need for effective adjuvant modalities. Given the rarity of these diseases, emphasis must be placed on collaborative research conducted on TEN.

Mediastinal masses are relatively uncommon. Surgical approach is often needed to diagnose mediastinal masses. Using endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) toward approaching a mediastinal mass has yet to be established. Here, we present a case of successful diagnosis of thymic cancer with the use of EBUS-TBNA.

The incidence of pericardial effusion in the U.S. is roughly 3.4% [1]. While most causes of pericardial effusions are indolent and transient, malignancy is a much more insidious cause that cannot be overlooked. Most cases of documented pericardial effusion secondary to malignancy have been due to mass effect from benign thymic tumors, such as thymomas. Our case highlights a 41-year-old male who presented with a dry cough and epigastric pain, found to have a large pericardial effusion and incidental thymic mass. The mass was biopsied and found to be keratinizing squamous cell carcinoma. This case expands our knowledge base as clinicians that pericardial effusions can be caused by malignant extension of tumors, rather than simply by mass effect of benign tumors.