Optimal therapy for thymoma

A late relapse thymoma and pure red cell aplasia case with an over 5 years of clinical response under everolimus

Although several agents showed some clinical activity in patients with recurrent thymoma, there is no standard treatment option. Here, we report a late relapse thymoma and pure red cell aplasia case, responsive to everolimus with over 5 years of clinical benefit following multiple lines of treatment. Everolimus controlled the rapidly progressive disease in our patient without significant toxicity.

Myasthenia Gravis: Novel Findings and Perspectives on Traditional to Regenerative Therapeutic Interventions

The prevalence of myasthenia gravis (MG), an autoimmune disorder, is increasing among all subsets of the population leading to an elevated economic and social burden. The pathogenesis of MG is characterized by the synthesis of autoantibodies against the acetylcholine receptor (AChR), low-density lipoprotein receptor-related protein 4 (LRP4), or muscle-specific kinase at the neuromuscular junction, thereby leading to muscular weakness and fatigue. Based on clinical and laboratory examinations, the research is focused on distinguishing MG from other autoimmune, genetic diseases of neuromuscular transmission. Technological advancements in machine learning, a subset of artificial intelligence (AI) have been assistive in accurate diagnosis and management. Besides, addressing the clinical needs of MG patients is critical to improving quality of life (QoL) and satisfaction. Lifestyle changes including physical exercise and traditional Chinese medicine/herbs have also been shown to exert an ameliorative impact on MG progression. To achieve enhanced therapeutic efficacy, cholinesterase inhibitors, immunosuppressive drugs, and steroids in addition to plasma exchange therapy are widely recommended. Under surgical intervention, thymectomy is the only feasible alternative to removing thymoma to overcome thymoma-associated MG. Although these conventional and current therapeutic approaches are effective, the associated adverse events and surgical complexity limit their wide application. Moreover, Restivo et al. also, to increase survival and QoL, further recent developments revealed that antibody, gene, and regenerative therapies (such as stem cells and exosomes) are currently being investigated as a safer and more efficacious alternative. Considering these above-mentioned points, we have comprehensively reviewed the recent advances in pathological etiologies of MG including COVID-19, and its therapeutic management.

Risk factor analysis of thymoma resection and its value in guiding clinical treatment

BACKGROUND

In this study, relationships between clinicopathologic characteristics and progression-free survival (PFS) of patients after thymomectomy were analyzed to provide valuable suggestions regarding the treatment of thymoma.

METHODS

Data from 187 thymoma patients undergoing surgery at Beijing Tongren Hospital between January 1, 2006, and December 31, 2015, were retrospectively reviewed. We explored the risk factors for PFS among sex, age, thymoma-associated MG, completeness of resection, histologic type and TNM stage, and investigated their interrelationship.

RESULTS

Among the 187 patients, 18 patients (9.63%) had tumor recurrence/metastasis, and all of whom had in situ recurrence or pleural metastasis, and most of them (10 of 18 patients) had MG symptoms that reappeared or were aggravated. Fifteen patients (8.02%) died, and myasthenic crisis was a leading cause. Based on Cox regression analysis, only age (HR = 3.16; 95% CI: 1.44-6.91; p = 0.004) and the completeness of resection (HR = 9.03; 95% CI: 2.58-31.55; p = 0.001) were independent risk factors for PFS. Furthermore, we found that the completeness of resection was related to the histologic type (p = 0.009) and TNM stage (p < 0.001) by Fisher's exact test.

CONCLUSIONS

The results of this cohort study remind us that we should pay attention to the reappearance or aggravation of MG after thymoma resection, because it is the leading cause of death and may indicate tumor progression. Furthermore, completeness of resection was related to the histologic type and TNM stage, but it was the independent risk factors of thymoma. Therefore, R0 resection is critical to the prognosis of thymoma.

Chinese expert consensus on the diagnosis and treatment of thymic epithelial tumors

Thymic epithelial tumors (TETs) are a relatively rare type of thoracic tumor, accounting for less than 1% of all tumors. The incidence of TETs is about 3.93/10000 in China, slightly higher than that of European and American countries. For resectable TETs, complete surgical resection is recommended. Radiotherapy or chemotherapy may be used as postoperative adjuvant treatment. Treatment for advanced, unresectable TETs consist mainly of radiotherapy and chemotherapy, but there is a lack of standard first- and second-line treatment regimens. Recently, targeted therapies and immune checkpoint inhibitors have shown promising outcomes in TETs. Based on the currently available clinical evidences and the opinions of the national experts, the Thymic Oncology Group of Yangtze River Delta Lung Cancer Cooperation Group (East China LUng caNcer Group, ECLUNG; Youth Committee) established this Chinese expert consensus on the clinical diagnosis and treatment of TETs, covering the epidemiology, diagnosis, treatment, prognosis and follow-up of TETs.

Fluorescence Imaging-Guided Identification of Thymic Masses Using Low-Dose Indocyanine Green

BACKGROUND

Indocyanine green (ICG) fluorescence imaging has been used to detect many types of tumors during surgery; however, there are few studies on thymic masses and the dose and time of ICG injection have not been optimized.

OBJECTIVE

We aimed to evaluate the optimal ICG injection dose and timing for detecting thymic masses during surgery.

METHOD

Forty-nine consecutive patients diagnosed with thymic masses on preoperative computed tomography (CT) and scheduled to undergo thymic cystectomy or thymectomy were included. Patients were administered 1, 2, or 5 mg/kg of ICG at different times. Thymic masses were observed during and after surgery using a near-infrared fluorescence imaging system, and the fluorescence signal tumor-to-normal ratio (TNR) was analyzed.

RESULTS

Among the 49 patients, 14 patients with thymic cysts showed negative fluorescence signals, 33 patients with thymoma or thymic carcinoma showed positive fluorescence signals, and 2 patients showed insufficient fluorescence signals. The diagnosis of thymic masses based on CT was correct in 32 (65%) of 49 cases; however, the differential diagnosis of thymic masses based on NIR signals was correct in 47 of 49 cases (96%), including 14 cases of thymic cysts (100%) and 33 cases of thymomas or thymic carcinomas (94%). In addition, TNR was not affected by the time or dose of ICG injection, histological type, stage, or tumor size.

CONCLUSIONS

Low-dose intravenous injection of ICG at flexible time can detect thymic tumors. In addition, thymic cysts can be distinguished from thymomas or thymic carcinomas during surgery by the absence of ICG fluorescence signals.

Invasive thymoma extending to the right atrium with superior vena cava syndrome presenting massive intracardiac thrombosis immediately after the start of chemotherapy: an autopsy case report

Invasive thymomas with intraluminal tumor thrombi are rare. Removal of the thymoma and infiltration of the superior vena cava (SVC) is a curative alternative. We report an autopsy case of invasive thymoma with intraluminal growth into the intracardiac right atrium extension. Furthermore, the patient died of massive intracardiac thrombosis 5 days after the start of chemotherapy. A 66-year-old man with SVC syndrome was referred to our hospital. He had been aware of swelling of the face for 6 months. The patient was diagnosed with invasive thymoma by a CT-guided needle biopsy of the anterior mediastinal mass. Contrast-enhanced chest computed tomography showed a mass in the anterior mediastinum extending to the SVC and right atrium. As a result of discussion with surgeons and radiotherapists, we planned a multidisciplinary treatment in which neoadjuvant chemotherapy would reduce the tumor size, and surgery and postoperative radiotherapy were followed by chemotherapy. He was administered neo-adjuvant chemotherapy with CBDCA + PTX (carboplatin, area under the curve = 6, and paclitaxel, 200 mg/m²). On the 4th day of chemotherapy, he suddenly developed obstructive shock due to intracardiac thrombosis in the right ventricle. We believe that chemotherapy may trigger rapid thrombus formation. If an invasive thymoma spreads into a large vessel or the right atrium, surgical treatment should be considered if possible. However, if surgery is impossible, administration of anticoagulants should be considered to prevent thrombus formation before chemotherapy.

Radiotherapy for thymic epithelial tumours: a review

Thymic epithelial tumours (TETs) represent a rare disease, yet they are the most common tumours of the anterior mediastinum. Due to the rare occurrence of TETs, evidence on optimal treatment is limited. Surgery is the treatment of choice in the management of TETs, while the role of postoperative radiotherapy (PORT) remains unresolved. PORT remains debated for thymomas, especially in completely resected stage II tumours, for which PORT may be more likely to benefit in the presence of aggressive histology (WHO subtype B2, B3) or extensive transcapsular invasion (Masaoka-Koga stage IIB). For stage III thymoma, evidence suggests an overall survival (OS) benefit for PORT after complete resection. For incompletely resected thymomas stage II or higher PORT is recommended. Thymic carcinomas at any stage with positive resection margins should be offered PORT. Radiotherapy plays an important role in the management of unresectable locally advanced TETs. Induction therapy (chemotherapy or chemoradiation) followed by surgery may be useful for locally advanced thymic malignancies initially considered as unresectable. Chemotherapy only is offered in patients with unresectable, metastatic tumours in palliative intent, checkpoint inhibitors may be promising for refractory diseases. Due to the lack of high-level evidence and the importance of a multidisciplinary approach, TETs should be discussed within a multidisciplinary team and the final recommendation should reflect individual patient preferences.

Effect of Postoperative Radiotherapy in Thymoma Patients: A SEER-Based Study

INTRODUCTION

The role of postoperative radiation therapy (PORT) for thymoma is under debate, especially in patients aged ≥60 years with an advanced stage (Masaoka stages III and IV). We aimed to evaluate the efficacy of PORT for thymoma in a population-based registry.

METHODS

A retrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) database was conducted to compare the outcomes of thymoma patients with or without PORT. The primary outcomes were overall survival (OS) and cancer-specific survival (CSS). Conditional inference tree analyses were performed for risk classification according to the study variables. Cox regression was performed to evaluate the prognostic effect of PORT in the specific subgroups.

RESULTS

A total of 2,236 patients were included. The conditional inference tree analysis identified that an age ≥60, a Masaoka stage ≥3, and the year of diagnosis were important factors when classifying patients into prognostic subgroups. PORT was found to be a protective predictor of OS in patients aged ≥60 years, those with a Masaoka stage III-IV, and those diagnosed after 2005. Further subgroup analyses revealed that PORT was significantly associated with a better OS (HR = 0.77) in patients aged ≥60 years, whereas it was not significantly associated with CSS.

CONCLUSIONS

An older age (≥60 years) is critical for predicting survival outcomes in thymoma patients. Moreover, patients aged ≥60 years could benefit from PORT in terms of OS.

The role of postoperative radiotherapy for thymomas: a multicentric retrospective evaluation from three Italian centers and review of the literature

Background

Thymoma is a rare mediastinal neoplasia. Surgery is the backbone of the treatment, but the role of postoperative radiotherapy (PORT) remains controversial. We aimed to obtain data on survival and safety in patients treated with PORT in three different Italian institutions.

Methods

We retrospectively analyzed 183 consecutive patients who underwent surgery from 1981 to 2015. According to the Masaoka-Koga staging system, 39.3%, 32.7%, 18.6% and 9.8% patients were in stage I, II, III and IV of disease, respectively. PORT was indicated in 114 patients (62.3%), while 69 subjects underwent surgery alone. Complete resection was obtained in 68 patients who underwent PORT. Adverse events (AEs) were graded according to CTCAE v4.0. We analyzed the recent literature to describe the current reports on PORT for resected thymoma.

Results

Mean follow-up was 130 months (range, 3–417 months). Overall survival (OS) at 1-, 5- and 10-year from surgery was 98.3%, 90.2% and 69.7% respectively. One-, 5- and 10-year disease specific survival (DSS) was 98.9%, 92.3% and 89.8% respectively. Disease free survival (DFS) at 1, 5 and 10 years from surgery was 96.7%, 88.3% and 82.8% respectively. Univariate analysis showed that complete resection, cell histology A-AB-B1 and stages I–II were significant predictors of better DSS and DFS. Multivariate analysis showed that sex, R0 margins and WHO histology was independent prognostic factors. Among patients treated with PORT, a trend towards better OS was evident with Masaoka stage I–II (P=0.09). Patients with R0 margins treated with PORT showed better OS and DSS (P=0.05). No differences in DSS for performance status (P=0.70), WHO histology (P=0.19), paraneoplastic syndrome (P=0.23) and surgical procedure (P=0.53) were evident. Patients treated with PORT had a higher level of acute AEs compared to surgery alone, but none of these was graded ≥3.

Conclusions

Our results confirmed that patients with incompletely resected thymoma had the worst OS and DSS. High grade acute toxicity was not different between PORT and surgery alone. Other trials reported a significant benefit in OS, DSS and DFS in stage IIb–IV thymoma treated with PORT.

Surgical management of thymic epithelial tumors

Resection is the mainstay of treatment for thymic epithelial tumors (TETs), with complete removal of the tumor and involved organs being the ultimate aim. The choice of surgical approach plays a major role in defining treatment success, and the optimal choice of method should thus provide an adequate surgical view to achieve complete tumor resection. While median sternotomy is considered the gold standard for access to the mediastinum, several minimally invasive approaches to thymectomy have been described, including video-assisted robotic-assisted thymectomy, although the oncological outcomes of that procedure remain unclear. A multimodal approach incorporating chemotherapy or chemoradiotherapy followed by extended surgery may improve resectability and outcomes for patients with advanced TETs. Surgical debulking is also reportedly acceptable for invasive thymoma because of its potential for achieving favorable outcomes. Re-resection is an acceptable option for patients with recurrent thymoma after initial resection, and repeat resection for recurrent pleural dissemination seems effective. Here, the literature on current clinical practices in the surgical management and treatment of TETs is reviewed.

Heart rupture repair during huge mediastinal mass resection - case report

BACKGROUND

Ventricular rupture is rarely described in the literature outside the context of myocardial infarction, infection or neoplasm. It is associated with a high mortality rate due to late presentation and delayed surgical intervention, which involves sutureless or sutured techniques. Comprehensive literature review failed to identify any case of intra-operative right ventricular heart rupture followed by myocardial repair and a complete recovery after a prolonged intensive care unit (ICU) stay.

CASE PRESENTATION

A 57-year-old previously healthy gentleman presented complaining of a new onset shortness of breath for 2 months. A large mediastinal mass was found on chest imaging and biopsy revealed a thymoma. Patient received a neoadjuvant Cisplatin/Doxorubicin/Cyclophosphamide (CAP) regimen chemotherapy then sternotomy and thymectomy en bloc with anterior pericardium. Post-thymectomy, the patient continued to be hypotensive in recovery despite aggressive fluid resuscitation. He was sent back to theatre, aggressive fluid resuscitation continued, surgical site exploration was done by reopening the sternum, and the bleeding source was identified and controlled, but intraoperative asystole developed. During internal cardiac massage, the right ventricle ruptured with a 3 cm defect which was successfully repaired using a pericardial patch without a bypass machine due to unavailability at our cancer center. The patient remained dependent on mechanical ventilation through tracheostomy for a total of 2 months due to bilateral phrenic nerve paralysis, was discharged from ICU to the surgical floor 66 days after the operation and weaned off ventilator support after 85 days, adequate respiratory and physical rehabilitation followed. Patient is doing very well now with excellent performance, and free of tumor recurrence 30 months after surgery.

CONCLUSION

Right ventricular rupture is rarely described outside the context of myocardial infarction and valvular heart disease. Tumor proximity to the heart and neoadjuvant cardiotoxic chemotherapy are the proposed causes for precipitating the cardiac rupture in our case. Post-surgical patients who receive early physical rehabilitation and respiratory physiotherapy have improved survival and outcome.

Comparison between CT and MRI in the Diagnostic Accuracy of Thymic Masses

Purpose: The aim of this study was to compare diagnostic accuracy between CT and MRI for thymic masses.

Methods: We searched literature and collected information on first author, publication year, cases of different types of thymic lesions, correct diagnostic cases of CT and MRI and results of quantitative analysis of CT and MRI. The ROC curve was applied to compare the diagnostic performance of different imaging modalities.

Results: Eight literatures were finally included and analyzed in this study. There were 253 cases examined by CT and 340 cases by MRI in total. We showed outcomes of quantitative analysis of each study in this article. The sensitivity of CT and MRI was both 100%, while the specificity was 75% and 80%, respectively. AUC of CT was 0.875 [95%CI: 0.473, 0.997] and that of MRI was 0.880 [95%CI: 0.531, 0.995].

Conclusion: The diagnostic accuracy of MRI is superior to CT in detecting thymomas, thymic cysts or thymic hyperplasia but that of CT and MRI is still unclear in differentiating thymic carcinomas and lymphomas/germ cell tumors.

Best practices for the management of thymic epithelial tumors: A position paper by the Italian collaborative group for ThYmic MalignanciEs (TYME)

Thymic epithelial tumors (TETs) are a heterogenous group of rare tumors, with a complex histopatological classification. Furthermore, the recent introduction of the first TNM staging system, that is scheduled to replace the Masaoka-Koga system, may create further difficulties in TET management, that remains challenging. Several guidelines for treatment of TETs are available and provide recommendations based mainly on non randomized trials and retrospective or limited series. Often the lack of evidence leads to formulation of indications based on expert opinions. As for other rare cancers it is crucial to create networks to coordinate the work among centres involved in treatment of these diseases in order to offer the best diagnostic and therapeutic tools. For this purpose, in 2014 a network named TYME (ThYmic MalignanciEs), was founded in Italy with the aim of improving care and research in TETs. In September 2017 a panel of multidisciplinary experts from TYME network and from other Italian centres strongly involved in TET diagnosis and treatment convened a first Italian Expert meeting together with representatives of association for patients affected by rare thoracic cancers Tu.To.R, to explore how these tumors are managed in the different centres of Italy compared to ESMO guidelines. In this paper we summarize the issues discussed during that meeting and we propose recommandations based on Masaoka Koga and the new TNM staging system.

Prognostic value of preoperative neutrophil-lymphocyte ratio is superior to platelet-lymphocyte ratio for survival in patients who underwent complete resection of thymic carcinoma

BACKGROUND

Preoperative neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) have prognostic value in patients with various operable tumors. The aim of our study was to determine whether NLR and PLR are predictive of survival in thymic carcinoma patients after complete resection.

METHODS

A total of seventy-nine patients who underwent complete resection of thymic carcinoma at our hospital between January 2005 and December 2015 were retrospectively enrolled. Differential leukocyte counts were collected before surgery, and the relationships of NLR, PLR, and other patient clinical variables with survival were estimated by Cox regression analysis and Kaplan-Meier survival analysis.

RESULTS

Univariate analysis found that a high level of NLR was associated with lower disease-free survival (DFS) (HR: 3.385, 95% CI: 1.073-10.678, P=0.037) and lower overall survival (OS) (HR: 12.836, 95% CI: 1.615-101.990, P=0.016). The optimal NLR threshold of 4.1 could stratify the patients with high risk of recurrence or metastasis (P=0.026) and death (P=0.006). Meanwhile, the NLR value of >4.1 in those patients was associated with bigger tumor size (P=0.035) and more advanced Masaoka stages (P=0.040) compared with NLR ≤4.1. However, the PLR and other variables were not significantly associated with survival in thymic carcinoma patients.

CONCLUSIONS

The preoperative NLR of >4.1 was significantly associated with larger tumor size, more advanced Masaoka stages and reduced DFS and OS, but was not an independent predictor of survival in thymic carcinoma patients after complete resection.

Postoperative radiotherapy and tumor recurrence after complete resection of stage II/III thymic tumor: a meta-analysis of cohort studies

BACKGROUND

Whether postoperative radiotherapy (PORT) is effective for reducing the recurrence risk in patients who received complete resection of the stage II or III thymic tumors has not been determined. A meta-analysis was performed by combining the results of all available controlled trials.

METHODS

PubMed, Cochrane's Library, and the Embase databases were searched for studies which compared the recurrence data for patients with complete resection of the stage II or III thymic tumors assigned to an observing group, or a PORT group. A random effect model was applied to combine the results.

RESULTS

Nineteen studies, all designed as retrospective cohort studies were included. These studies included 663 patients of PORT group and 617 patients of observing group. The recurrence rate for the patients in PORT group and observing group were 12.4% and 11.5%, respectively. Results of our study indicated that PORT has no significant influence on recurrent risk in patients with stage II or III thymic tumor after complete resection (odds ratio 1.02, 95% confidence interval 0.55-1.90, P=0.96). When stratified by stages, our meta-analyses did not indicate any significant effects of PORT on recurrent outcomes in either the stage II or the stage III patients. Moreover, subsequent analysis limited to studies only including patients with thymoma or thymic carcinoma also did not support the benefits of PORT on recurrent outcomes.

CONCLUSION

Although derived from retrospective cohort studies, current evidence did not support any benefit of PORT on recurrent risk in patients with complete resection of the stage II or III thymic tumors.

Pure Red Cell Aplasia Following Interleukin-2 Therapy

A 61-year-old woman with metastatic renal cell carcinoma underwent systemic treatment with high-dose interleukin-2 (IL-2). Anemia requiring transfusion of 1 unit of packed red blood cells (PRBCs) was required during the second week of IL-2 therapy. One month following completion of high-dose IL-2 treatment, she was hospitalized for severe, symptomatic anemia and received 5 units of PRBCs. She was referred back for evaluation. A complete hematologic evaluation was performed including antiviral serology, evaluation for hemolysis, complete iron studies, and finally bone marrow aspiration and biopsy. The diagnosis was pure red cell aplasia, and no inciting viral cause could be ascertained. She required PRBCs for 5 months following IL-2 therapy. It was concluded that IL-2 was the cause of her red cell aplasia. This subsequently resolved spontaneously, and she had normal hemoglobin and hematocrit, respectively, 1 and 2 years after treatment.

Adjuvant treatment in patients at high risk of recurrence of thymoma: efficacy and safety of a three-dimensional conformal radiation therapy regimen

Background

The clinical benefits of postoperative radiation therapy (PORT) for patients with thymoma are still controversial. In the absence of defined guidelines, prognostic factors such as stage, status of surgical margins, and histology are often considered to guide the choice of adjuvant treatment (radiotherapy and/or chemotherapy). In this study, we describe our single-institution experience of three-dimensional conformal PORT administered as adjuvant treatment to patients with thymoma.

Methods

Twenty-two consecutive thymoma patients (eleven male and eleven female) with a median age of 52 years and treated at our institution by PORT were analyzed. The patients were considered at high risk of recurrence, having at least one of the following features: stage IIB or III, involved resection margins, or thymic carcinoma histology. Three-dimensional conformal PORT with a median total dose on clinical target volume of 50 (range 44–60) Gy was delivered to the tumor bed by 6–20 MV X-ray of the linear accelerator. Follow-up after radiotherapy was done by computed tomography scan every 6 months for 2 years and yearly thereafter.

Results

Two of the 22 patients developed local recurrence and four developed distant metastases. Median overall survival was 100 months, and the 3-year and 5-year survival rates were 83% and 74%, respectively. Median disease-free survival was 90 months, and the 5-year recurrence rate was 32%. On univariate analysis, pathologic stage III and presence of positive surgical margins had a significant impact on patient prognosis. Radiation toxicity was mild in most patients and no severe toxicity was registered.

Conclusion

Adjuvant radiotherapy achieved good local control and showed an acceptable toxicity profile in patients with high-risk thymoma.

Management of metastatic malignant thymoma with advanced radiation and chemotherapy techniques: report of a rare case

Malignant thymomas are rare epithelial neoplasms of the anterior superior mediastinum that are typically invasive in nature and have a higher risk of relapse that may ultimately lead to death. Here we report a case of an advanced malignant thymoma that was successfully treated with neoadjuvant chemotherapy followed by surgical resection and subsequently with advanced and novel radiation therapy techniques. A 65-year-old male was diagnosed with a stage IV malignant thymoma with multiple metastatic lesions involving the left peripheral lung and pericardium. Initial neoadjuvant chemotherapy with a cisplatin-based regimen resulted in a partial response allowing the inoperable tumor to become operable. Following surgical resection of the residual disease, the tumor recurred within a year. The patient then underwent a course of targeted three-dimensional intensity modulated radiation therapy (IMRT) and image-guided radiation therapy (IGRT). Five years after radiation therapy, the localized soft tissue thickening at the left upper lung anterior pleural space had resolved. Seven years after radiation therapy the tumor mass had completely resolved. No recurrences were seen and the patient is well even 8 years after IMRT/IGRT with a favorable outcome. Chemotherapy with targeted three-dimensional IMRT/IGRT should be considered the primary modality for the management of advanced malignant thymoma patients.

Therapy for thymic epithelial tumors

Thymoma is the most common tumor of the anterior mediastinum. This tumor is associated with unique paraneoplastic syndromes. The rarity of this tumor has somewhat obscured the optimal treatment for this disease. The World Health Organization classification system, which published in 1999, appears to be an advance in our understanding of thymoma. The Masaoka classification is now the most widely accepted and is an excellent predictor of the prognosis of thymoma. Now the International Thymic Malignancy Interest Group is currently engaged in the development of a validated formal TNM classification system for thymic malignancies. The optimal treatment of thymoma is performed according to its clinical stage. Surgery remains the mainstay of treatment for thymic epithelial tumors. Minimally invasive surgery including thoracoscopic surgery and robotic surgery for stage I and II thymomas is increasing now. The value of postoperative radiotherapy in completely resected stage II or III tumors is questionable. As thymomas have a moderate response rate to chemotherapy or radiotherapy, multimodality therapy involving surgery, chemotherapy and radiotherapy appears to increase the rate of complete resection and survival in the advanced (stage III and IV) thymomas.

Thymic neoplasm: a rare disease with a complex clinical presentation

Thymic neoplasms constitute a broad category of rare lesions with a wide spectrum of pathologic characteristics and clinical presentations which therefore require a high index of suspicion to diagnose. The natural history of the disease is seldom predictable, anywhere from an indolent to an aggressively malignant course. Although the classification and staging of these lesions are complex and controversial, complete radical surgical resection remains the gold standard of therapy. Radiation and chemotherapy are important elements of the multimodality approach to treating these patients and it is important for thoracic surgeons to work closely with their colleagues in other disciplines in the management of and future research endeavors in thymic neoplasm. In this review, we discuss the evaluation of the patient with an anterior mediastinal mass, the classification and staging of thymic neoplasms, the role of surgery, radiation and chemotherapy in treating this disease, as well as future directions in research for novel targeted therapies.

Thymomas in childhood: 11 cases from a single institution

AIM

Thymomas are rare in children. Our aim was to review clinical and pathologic characteristics and outcome in children with thymomas.

PATIENTS AND METHODS

Between 1979 and 2011, 11 children with thymomas were diagnosed. Hospital files were reviewed for presenting complaints, clinical, radiologic, and other laboratory data, surgical practices, chemotherapy and radiotherapy outcomes.

RESULTS

Median age was 8 years (range, 1 to 13 y). Male to female ratio was 9/2. Most common initial complaints were dyspnea, cough, chest pain, and fever. Median time from onset of symptoms was 1 month (range, 0.23 to 3 mo). Associated conditions including hyper-IgE syndrome, hypogammaglobulinemia, and systemic lupus erythematosus plus idiopathic thrombocytopenic purpura were present in 3 patients. Chest x-rays and/or thoracic computed tomographies displayed thymic hyperplasia and/or masses in anterior mediastinum accompanied by pleural (n = 2) and pericardial effusions (n = 1), pulmonary metastases (n = 1), and cervical lymph node metastasis (n = 1). Compression or invasion of trachea or vessels was documented in 5 cases. Seven cases underwent initial tumor resection; others experienced open or trucut biopsies. Histopathologically, 5 cases had invasive and 6 had benign thymomas. Benign thymomas did not receive any postoperative treatment; all cases are disease free at a median follow-up of 211 months. Three of 5 cases with invasive thymomas underwent surgery, 4/5 received chemotherapy and external radiotherapy (3600 to 4500 cGy). Two invasive thymomas died of disease. Three cases with invasive thymomas are disease free at a median follow-up of 209 months.

CONCLUSIONS

Benign thymomas have excellent prognosis. For invasive thymomas with or without metastasis, radiotherapy, and chemotherapy offers survival advantage. Complete surgical resection may increase chances for cure.

Entire hemithorax irradiation for Masaoka stage IVa thymomas

Thymomas are rare neoplasms that have an indolent growth with a preferentially intra-thoracic dissemination pattern. Surgery is currently the standard treatment of thymomas; however radiotherapy is often used in an adjuvant setting due to a high sensitivity of these tumors to such treatment. Postoperative entire hemithoracic irradiation has been used in selected Masaoka stage IVa cases after complete surgical excision of metastatic lesions. In the present article, the authors report three cases of Masaoka stage IVa thymoma that underwent entire hemithorax irradiation after surgical excision of metastatic lesions. The first two patients presented as stage IVa thymomas. The third case consisted of a pleural recurrence of a thymoma. Hemithoracic irradiation with low doses has been used by different authors; the available data shows that it is a well-tolerated treatment that could potentially lead to better loco-regional control and increased overall survival.

[Spontaneous regression of epithelial thymic tumours]

INTRODUCTION

Spontaneous regression of an epithelial thymic tumour has been reported but seems extremely rare. Its mechanism is unknown.

CASE REPORT

We report two cases of epithelial thymic tumour, either histologically proven or highly suspected on imaging, that regressed spontaneously (partially in one patient and totally in the other).

CONCLUSION

Spontaneous regression of an epithelial thymic tumour is very rare but this possibility could lead to clinical and radiological monitoring rather than surgery in selected patients.

A case of middle mediastinal thymoma

A 56-year-old male was referred to our clinic after an abnormality was found on chest X-ray films during regular health examinations. Middle mediastinal tumor was detected by computed tomography, he was admitted for surgical treatment. The tumor was removed by surgery, and a pathological diagnosis of mixed thymoma (type AB, the World Health Organization Classification) was made by examining the resected specimen. Because the tumor had invaded to its capsule, it was considered to be a stage II thymoma according to the Masaoka staging system. Postoperative radiation therapy (50 Gy) was administered to the mediastinum. The patient has remained disease-free and without any recurrence as of 9 years and 8 months after the operation. We herein present our findings because middle mediastinal thymoma is incredibly rare.

Induction therapy for thymic malignancies

Thymic malignancies are rare tumors of the chest that express a broad range of biological behaviors. Surgery remains the mainstay of therapy, and complete surgical resection is the primary predictor of long-term survival. Although there is a paucity of clinical trials assessing the role of induction/adjuvant chemotherapy and/or radiation therapy in the treatment of thymic malignancies, existing data suggest that induction therapy should be offered for the treatment of advanced-stage disease, and postoperative radiation for specific stages.

Myasthenia gravis: a review of available treatment approaches

Patients with autoimmune myasthenia gravis (MG) should be further classified before initiating therapy, as treatment response varies for ocular versus generalised, early onset versus late onset, and acetylcholine receptor antibody positive versus MuSK antibody positive disease. Most patients need immunosuppression in addition to symptomatic therapy. Prednisolone and azathioprine represent first choice drugs, whereas several second choice options are recommended and should be considered. Thymectomy should be undertaken in MG with thymoma and in generalised, early-onset MG. For MG crises and other acute exacerbations, intravenous immunoglobulin (IvIg) and plasma exchange are equally effective and safe treatments. Children and females in child bearing age need special attention regarding potential side effects of immunosuppressive therapy. MG pathogenesis is known in detail, but the immune therapy is still surprisingly unspecific, without a pin-pointed attack on the defined disease-inducing antigen-antibody reaction being available.

Prolonged survival in advanced thymoma: Effectiveness of sequential multiple lines of chemotherapy in an inoperable case

A standard therapeutic approach for advanced malignant thymoma has yet to be defined given the rarity of this condition. We present a patient with advanced thymoma, evaluated as inoperable at diagnosis due to multiple serosal metastases. The strong constitution and determination of the patient allowed treatment with six distinct and subsequent chemotherapy regimens, all administered on an outpatient basis. A survival of 64 months from diagnosis was achieved. A favorable clinical response was obtained after the first three treatment lines, with the disappearance of all lesions on both computed tomography and positron emission tomography (PET) images. However, this result was not confirmed by surgical exploration of the thorax, undertaken with the aim of radical excision of possible residual disease. The presence of multiple pleural nodules, not evident on the imaging techniques, prevented even limited tumor debulking. The chemotherapy lines administered following detection of the lessions, stabilized the disease for a further 2 years, while a satisfactory quality of life was maintained. Only in the last months did the tumor progress and signs of cardiotoxicity appear, with the latter constituting the eventual cause of death. This case is important since the medical literature does not indicate non-cross-resistant regimens for advanced thymoma following second-line chemotherapy, and the sequence of regimens presented in this case study may serve as a feasible outline program. Moreover, we highlight the known possibility of false-negative PET studies, which can occur despite the claimed glucose avidity of thymoma tissue.

Thymoma and autoimmunity

The thymus is a central lymphatic organ that is responsible for many immunological functions, including the production of mature, functional T cells and the induction of self-tolerance. Benign or malignant tumors may originate from the thymus gland, with thymoma being the most common and accounting for 50% of anterior mediastinal tumors. Malignancies linked to thymoma include the loss of self-tolerance and the presence of autoimmunity. In this review, we compiled the current scientific evidence detailing the various interactions between thymoma and autoimmune diseases, including myasthenia gravis, systemic lupus erythematosus, inappropriate antidiuretic hormone secretion, pure red cell aplasia, pernicious anemia, pemphigus and autoimmune thyroid diseases. In recent years, several mechanisms have been proposed to explain these interactions. Most are based on the assumption that the 'sick' thymus, like the 'normal' thymus, can generate mature T cells; however, the T cells generated by the sick thymus are impaired and thus may exert cellular autoreactivity. Here, we present several theories that may shed light on the loss of self-tolerance associated with this epithelial tumor of the thymus.

New predictors of response to neoadjuvant chemotherapy and survival for invasive thymoma: a retrospective analysis

BACKGROUND

Cell-cycle protein (p27, p21, and p53) expression can predict response to neoadjuvant chemotherapy and prognosis in some neoplasms. This study evaluated whether these markers could also be effective in invasive thymoma during a multimodality treatment.

METHODS

Between 1989 and 2008, 33 patients with invasive thymoma underwent surgical resection after neoadjuvant chemotherapy. Expression of p27, p21, and p53 was assessed using immunohistochemistry in specimens retrieved pre and post chemotherapy. Factors influencing response to neoadjuvant chemotherapy and survival were investigated by univariate and multivariate analysis. Good response was defined as complete disappearance of tumor at imaging or necrosis >90% at pathologic studies.

RESULTS

Twelve patients disclosed an imaging good response. Complete resection was possible in 17 patients, 9 of whom had presented imaging good response and 11 of whom had revealed pathologic good response. On univariate analysis both imaging and pathologic poor responses were significantly associated with incomplete resection (P = 0.04 and P = 0.03, respectively) and preneoadjuvant triple combination of p27 low, p21 low, and p53 high expressions (P = 0.001 and P < 0.0001, respectively), the last factor being the only one selected on logistic regression (P = 0.01 and P = 0.005, respectively). Long-term survival analysis was negatively influenced by triple combination of p27, p21, and p53 (P < 0.0001) and incomplete resection (P < 0.0001), which were also selected on Cox's regression (P = 0.004 and P = 0.02, respectively).

CONCLUSIONS

The triple combination of p27 low, p21 low, and p53 high expressions was the most significant predictor of imaging and pathologic poor responses to neoadjuvant chemotherapy in invasive thymoma. This combination together with incomplete resection was also the most significant negative predictor of long-term survival.

[Epithelial tumours of the thymus]

Epithelial tumours of the thymus include thymomas, thymic carcinomas and neuro-endocrine tumours. Rare, they nevertheless represent 20% of all mediastinal tumours and 50% of those located in the anterior mediastinum. Thymomas, in particular, can be associated to auto-immune disorders, among which predominates myasthenia gravis. Their clinical behaviour varies widely, from a relative indolence to the potential of lymph node and/or systematic metastases. However, even patients with an invasive disease may have a long clinical history, explaining that a 10-year or 20-year survival from diagnosis does not imply a definitive cure. In daily practice, both the clinical Masaoka's staging system and the WHO histological classification condition the treatment strategies and allow to anticipate the prognosis. The initial treatment, as well as that of the recurrence, is based mainly on a complete resection. Postoperative radiotherapy is systematically added to the treatment of invasive tumours and/or to those with an aggressive histological subtype. Inoperable or metastatic tumours require a cisplatine and anthracyclin-based chemotherapy, followed by radical surgery and/or radiotherapy.

Ectopic thymoma of the lung; a rare case report and review of the literature

Introduction

Ectopic thymoma is a rare neoplasm, which can be developed in various sites, with the lung being amongst the rarest.

Case presentation

In this paper, we present the case of a woman with a slow-growing ectopic thymoma, stemming from the visceral pleura of the upper lobe of the left lung anteriorly, extending into the left lung and the cardiac wall, invading the fatty tissue near the pericardium, notably without infiltrating the lung or cardiac parenchyma. The thymoma was successfully removed via thoracotomy.

Conclusion

Ectopic thymoma is an uncommon neoplasm. To our knowledge, a case of an ectopic thymoma stemming from the visceral pleura of the lung is extremely rare.

Adjuvant radiotherapy for thymic epithelial tumors: a systematic review and meta-analysis

Adjuvant radiotherapy after complete resection of localized, invasive thymic epithelial tumors is considered by many to be the standard of care, despite little supporting literature. We hypothesized that individual studies may lack statistical power to demonstrate a reduction in recurrence with this approach, but meta-analysis of published data may allow for more adequate statistical evaluation. Analysis of data from 592 patients with completely resected stage II or III thymic epithelial tumors, however, revealed no statistically significant reduction in recurrence after adjuvant radiotherapy (odds ratio 1.05; 95% confidence interval: 0.63 to 1.75; p = 0.840). Additionally, the majority of publications suggest that the most common sites of recurrence are the lung, pleura, and diaphragm, even when incompletely resected patients are included.

The Correlation of the World Health Organization Histologic Classification of Thymic Epithelial Tumors and Its Prognosis: A Clinicopathologic Study of 108 Patients From China

This study retrospectively reviewed the clinicopathological features of thymic epithelial tumors in 108 patients, and evaluated World Health Organization (WHO) histologic classification of thymic tumors. Other prognostic factors, including age, gender, clinical stage, and completeness of tumor resection were also analyzed. Seven type A tumors, 19 type AB, 23 type B1, 19 type B2, 27 type B3, and 13 thymic carcinomas were studied. The 5-year and 10-year survival rates were 100% after resection of tumor types A and AB; 93% and 81% for B1; 83% and 70% for B2; and 43% and 33% for B3. The overall 5-year and 10-year survival rates were 72.0% and 63.0%, respectively. Tumor classification was highly significant in predicting survival ( P .001) and also reflected the clinical behavior of tumors. The Masaoka stage was the most important independent prognostic index in thymomas. The WHO histologic subtype and completeness of resection were also important prognostic factors.