Thymomas: review of current clinical practice

Wide en-bloc thymectomy and venous axis reconstruction in Masaoka stage IIIB thymoma: a case report and literature review

Thymomas are rare tumors originating from thymic tissue and rarely metastasize. They can be diagnosed either incidentally or symptomatically when compressing or invading nearby structure. A 36-year-old man presented with significant high-grade fever, chest pain that worsens upon lying down, and dyspnea. A chest X-Ray and computed tomography followed by biopsy confirmed the diagnosis of thymoma. The management included chemotherapy cycles, followed by surgery. Pericardiectomy was performed with en-bloc thymectomy and partial resection of the infiltrating lung. Venous drainage was restored by 8/16 mm inverted bifurcated brachiocephalic-superior vena cava Dacron bypass. The pericardium was reconstructed by a synthetic Dacron patch, and the right diaphragm metastasis was resected. Neoadjuvant chemotherapy was initiated. After 3 months of follow-up, no recurrence was evidenced by computed tomography.

Premalignant Lesions in the Kidney Transplant Candidate

End-stage kidney disease patients who are referred for transplant undergo an extensive evaluation process to ensure their health prior to transplant due in part to the shortage of available organs. Although management and surveillance guidelines exist for malignancies identified in the transplant and waitlist populations, less is written about the management of premalignant lesions in this population. This review covers the less common premalignant lesions (intraductal papillary mucinous neoplasm, gastrointestinal stromal tumor, thymoma, and pancreatic neuroendocrine tumor) that can be found in the transplant candidate population. High-level evidence for the management of these rarer premalignant lesions in the transplant population is lacking, and this review extrapolates evidence from the general population and should not be a substitute for a multidisciplinary discussion with medical and surgical oncologists.

Prognosis and surgical outcomes of the total thymectomy versus thymomectomy in non-myasthenic patients with early-stage thymoma: A systematic review and meta-analysis

Whether thymectomy (TM) or thymomectomy (TMM) is better for non-myasthenic patients with early-stage thymoma. We conducted a meta-analysis to compare the clinical outcomes and prognoses of non-myasthenic patients with early-stage thymoma treated using thymectomy versus thymomectomy. PubMed, Embase, Cochrane Library and CNKI databases were systematically searched for relevant studies on the surgical treatment (TM and TMM) of non-myasthenic patients with early-stage thymoma published before March 2022. The Newcastle-Ottawa scale was used to evaluate the quality of the studies, and the data were analyzed using RevMan version 5.30. Fixed or random effect models were used for the meta-analysis depending on heterogeneity. Subgroup analyses were performed to compare short-term perioperative and long-term tumor outcomes. A total of 15 eligible studies, including 3023 patients, were identified in the electronic databases. Our analysis indicated that TMM patients might benefit from a shorter duration of surgery (p = 0.006), lower blood loss volume (p < 0.001), less postoperative drainage (p = 0.03), and a shorter hospital stay (p = 0.009). There were no significant differences in the overall survival rate (p = 0.47) or disease-free survival rate (p = 0.66) between the two surgery treatment groups. Likewise, TM and TMM were similar in the administration of adjuvant therapy (p = 0.29), resection completeness (p = 0.38), and postoperative thymoma recurrence (p = 0.99). Our study revealed that TMM might be a more appropriate option in treating non-myasthenic patients with early-stage thymoma.

Incidental giant thymoma-a reminder of the importance of a global look of the imaging scans

A 49-year-old female patient, without previous medical history, underwent a thoracic CT due to SARS-CoV2 infection. This exam revealed a heterogeneous mass in the anterior mediastinum with 11 × 8.8 cm in close contact with main thoracic vessels and pericardium. Surgical biopsy documented a B2 thymoma. This clinical case reminds the importance of a systematic and global look of the imaging scans. Years before the thymoma diagnosis, the patient underwent a shoulder X-ray due to musculoskeletal pain, where an irregular shape of the aortic arch was visible, probably related to the growing mediastinal mass. An earlier diagnosis would allow a complete mass resection without such extensive surgery and less morbidity.

Molecular profiling of rare thymoma using next-generation sequencing: meta-analysis

BACKGROUND

Thymomas belong to rare tumors giving rise to thymic epithelial tissue. There is a classification of several forms of thymoma: A, AB, B1, B2, B3, thymic carcinoma (TC) and thymic neuroendocrine thymoma. In this meta-analysis study, we have focused on thymoma using articles based on the disease's next-generation sequencing (NGS) genomic profiling.

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis of the prevalence of studies that discovered the genes and variants occurring in the less aggressive forms of the thymic epithelial tumors. Studies published before 12^th December 2022 were identified through PubMed, Web of Science (WoS), and SCOPUS databases. Two reviewers have searched for the bases and selected the articles for the final analysis, based on well-defined exclusion and inclusion criteria.

RESULTS

Finally, 12 publications were included in the qualitative as well as quantitative analysis. The three genes, GTF2I, TP53, and HRAS, emerged as disease-significant in the observed studies. The Odds Ratio for all three extracted genes GTF2I (OR = 1.58, CI [1.51, 1.66] p < 0.00001), TP53 (OR = 1.36, CI [1.12, 1.65], p < 0.002), and HRAS (OR = 1.02, CI [1.00, 1.04], p < 0.001).

CONCLUSIONS

According to obtained data, we noticed that the GTF2I gene exhibits a significant prevalence in the cohort of observed thymoma patients. Moreover, analyzing published articles NGS has suggested GTF2I, TP53, and HRAS genes as the most frequently mutated genes in thymoma that have pathogenic single nucleotide variants (SNV) and Insertion/Deletion (InDel), which contribute to disease development and progression. These variants could be valuable biomarkers and target points specific to thymoma.

A phase II study of buparlisib in relapsed or refractory thymomas

PURPOSE

To investigate the efficacy and safety of buparlisib, an oral pan-PI3K inhibitor, in relapsed or refractory thymomas.

METHODS

This was a single center, single arm, open label phase II trial of buparlisib in patients with recurrent thymoma who have progressed after at least one prior line of treatment. The primary endpoint was objective response rate (complete response [CR] + partial response [PR]). Secondary endpoints included toxicity; progression free survival (PFS); overall survival (OS); disease control rate (DCR), i.e., the percentage of patients who achieve either PR or CR or stable disease [SD] for at least 4 months.

RESULTS

Between 10/13/2014 and 1/18/2017, 14 patients with stage IV disease were enrolled. Median age was 58y (23-74). 71% were females and 71% white. All patients had WHO B2 (29%) or B3 (71%) thymoma. Patients received buparlisib for a median of 4.5m (2-33). At a median follow up of 16.6m (2.4-31.3), onr patients (7%) achieved a PR. DCR was 50%. Median PFS was 11.1m (95% CI 2.9 - 18.8). Median OS, updated as of March, 2021 was 22.5m (10.7-31.3). Most common grade 3-4 adverse events related to buparlisib were dyspnea (21%), rash (14%), elevated transaminases (14%), cough (7%), pneumonitis (7%), anxiety (7%), fatigue (7%) and hyperglycemia (7%). Reasons for treatment discontinuation included progression of disease (n= 5), rash (n=4), pulmonary toxicity (n=3), sinusitis (n=1), and disseminated toxoplasmosis plus autoimmune cholangitis (n=1). As of 3/2021, 8 patients have died, 7 due to disease progression and 1 due to central nervous system toxoplasmosis and autoimmune cholangitis.

CONCLUSION

Buparlisib showed modest activity in patients with relapsed or refractory thymomas. Further investigation of PI3K pathway targeted therapy in thymoma is warranted. (clinicaltrials.gov ID: NCT02220855).

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov, identifier (NCT02220855).

A case of uniportal VATS thymectomy for Thymoma associated with myasthenia gravis and toxic multinodular goiter

BACKGROUND

Thymoma is a rare neoplasm, which may be associated with autoimmune disorders, the occurrence of hyperthyroidism in the patients with thymoma is rare.

CLINICAL PRESENTATION

Here we present an extremely rare case of a 56-year-old female patient who was discovered to have malignant thymoma with associated myasthenia gravis and hyperthyroidism due to toxic multinodular goiter. Our patient started to complain of difficulty breathing and swallowing, Chest CT scan was done and revealed an anterior mediastinal mass, measures about 4.1 × 3.1 × 2.2 cm with enlarged lymph node mostly representing thymoma. Complete thymectomy was performed via uniportal video-assisted thoracoscopic surgery, and the patient's postoperative recovery was uneventful. Microscopic histopathology findings corresponded to thymoma type B1.

CONCLUSION

The coexistence of thymoma, MG and toxic multinodular goiter is extremely rare. MG should always be suspected in a patient with thymoma. VATS thymectomy has been increasingly used to treat thymoma as it has several advantages over open surgery.

Canine Epithelial Thymic Tumors: Outcome in 28 Dogs Treated by Surgery

Simple Summary

Thymoma is a tumor of the cranial mediastinum rarely reported in dogs and should be differentiated from mediastinal lymphoma. CT and fine-needle aspirates or core biopsies are helpful in differential diagnosis, but flow cytometry may improve the pre-operative diagnostic ability. In thymomas, paraneoplastic syndromes such as myasthenia gravis and hypercalcemia may develop concurrently with the tumor. Their role as prognostic factors is not well determined. Surgical excision is the treatment of choice, but adjuvant radiotherapy and/or chemotherapy may prolong survival in cases of incomplete excision or if a thymic carcinoma is diagnosed. Local recurrence and metastasis are infrequently reported; therefore, a long survival is expected if the tumor is completely excised or if adjuvant therapy is undertaken. This article reports the authors’ experience with 28 dogs affected by 18 thymomas and 10 thymic carcinomas surgically treated from January 2000 to August 2021. The median overall survival time of the entire population was 1137 days; the median disease-free time was 903 days. Dogs with thymic carcinomas had significantly shorter disease-free intervals and shorter, although not statistically significant, survival times. Dogs with Masaoka Stage III tumors had worse outcomes.

Abstract

Thymoma is a tumor rarely reported in dogs and should be differentiated from mediastinal lymphoma. Clinical signs may have a late onset, and thymoma is often diagnosed when symptoms related to the space-occupying effect or paraneoplastic syndromes occur. CT and fine-needle aspirates or core biopsies are helpful in differential diagnosis, but flow cytometry may improve the pre-operative diagnostic ability. Concurrent paraneoplastic syndromes such as myasthenia gravis and hypercalcemia have been reported; however, their role as prognostic factors is not well determined. Surgical excision is the treatment of choice; adjuvant radiotherapy and/or chemotherapy may prolong survival in cases of incomplete excision or when a thymic carcinoma is diagnosed. Local recurrence and metastasis are infrequently reported; therefore, a long survival time is expected if the tumor is completely excised or if adjuvant therapy is undertaken. This article reports the authors’ experience with 28 dogs affected by 18 thymomas and 10 thymic carcinomas. The median overall survival in this series was 1173 days, and the median disease-free interval was 903 days. Dogs with thymic carcinoma had significantly shorter disease-free intervals and shorter, although not statistically significant, survival times. Dogs with Masaoka Stage III tumors had worse outcomes.

Biological and pharmacological activities of noscapine: Focusing on its receptors and mechanisms

Noscapine has been mentioned as one of the effective drugs with potential therapeutic applications. With few side effects and amazing capabilities, noscapine can be considered different from other opioids-like structure compounds. Since 1930, extensive studies have been conducted in the field of pharmacological treatments from against malaria to control cough and cancer treatment. Furthermore, recent studies have shown that noscapine and some analogues, like 9-bromonoscapine, amino noscapine, and 9-nitronoscapine, can be used to treat polycystic ovaries syndrome, stroke, and other diseases. Given the numerous results presented in this field and the role of different receptors in the therapeutic effects of noscapine, we aimed to review the properties, therapeutic effects, and the role of receptors in the treatment of noscapine.

Giant thymoma presenting as a large bilateral intrathoracic mass: A case report and a comparison between median sternotomy and hemiclamshell approach

Introduction

Thymoma is an epithelial tumor that commonly lies in the anterior mediastinum. It rarely extends to the pleural cavities. There is no standard approach for resecting similar giant thymomas.

Case presentation

An eighteen-year-old woman presented with a six-month history of progressive exertional dyspnea, weight loss, and loss of appetite. Radiological imaging demonstrated a giant mediastinal mass extending to both pleural cavities, a transthoracic needle biopsy was then performed, which indicated thymic hyperplasia.

Clinical discussion

The tumor was completely resected using a two-step approach, starting with a median sternotomy then extending it to a hemiclamshell incision, which provided better exposure of the tumor and caused less morbidity.

The left part of the thymoma was resected using a median sternotomy, which took a relatively long time and caused significant blood loss. Then the incision was extended to a hemiclamshell incision through the pleural cavity to remove the right part of the tumor. This approach helped us to visualize the tumor better and did not cause any significant blood loss.

The removed mass measured 36 × 29 × 10 cm and weighed 4500 g. Pathologic diagnosis indicated a type B1 tumor with no capsular invasion according to the World Health Organization classification.

Conclusion

The hemiclamshell approach is superior to the median sternotomy incision in resecting giant thymomas extending to the pleural cavity, as it saves time and causes less morbidity.

•

Giant Thymoma is an extremely rare clinical entity.

•

It is very uncommon for a thymoma to reach both pleural cavities.

•

Comparing the median sternotomy to the hemiclamshell approach in resecting giant thymomas extending to the mediastinum.

•

The hemiclamshell approach caused less morbidity and no significant blood loss compared to the median sternotomy.

How to obtain adequate biopsy specımen in suspected thymic tumors

Pathologic diagnosis of thymic tumors (TTs) can be made by surgical or nonsurgical procedures. About 20% of TTs had been diagnosed by pretreatment biopsy methods while the rest had gone to surgery for diagnosis and treatment. However, in the last two decades there was an increase in pretreatment procedures for optimal management of locally advanced or metastatic TTs. Pretreatment tissue diagnosis of a noninvasive TT is not a standard option but is required if there is suspect or atypical clinical presentation and imaging, an invasive tumor requiring a nonsurgical approach or preoperative chemotherapy or chemo-radiotherapy, strong possibility of lymphoma or unclear differential diagnosis between lymphoma or other solid tumor by imaging studies, or suspicion of a metastatic lesion. In surgical diagnosis anterior mediastinotomy, video-assisted thoracic surgery or mediastinoscopy can be chosen for invasive TTs whereas total resection is performed for small, noninvasive tumors. Nonsurgical diagnosis can be made by transthoracic fine or core needle biopsies (TTFNA, TTCNB), conventional bronchoscopy, endobronchial ultrasonography-guided transbronchial needle aspiration (EBUS-TBNA), endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) or medical thoracoscopy depending on procedural amenability according to tumor extension. TTFNA and TTCNB have been the most frequently used nonsurgical methods. However, there is an upward trend in using conventional bronchoscopy, EBUS-TBNA, EUS-FNA and medical thoracoscopy recently. To increase the diagnostic performance of these procedures in TTs, recommendations are (I) obtaining histologic specimens, (II) combining smears or liquid based cytology preparations and cell blocks, (III) obtaining multiple sufficient samples, (IV) combining histologic and cytologic specimens, (V) performing morphologic, immunohistochemical and molecular analyses on all specimens, (VI) using rapid onsite evaluation for cytologic specimens, (VII) correlating pathologic, clinical and radiologic findings, (VIII) consulting experienced pathologists.

Perioperative risk factors for occurrence of myasthenia gravis after thymectomy in patients with thymoma

OBJECTIVES

The goal of this study was to identify the relationship between clinical characteristics and the occurrence of postoperative myasthenia gravis (PMG) in patients with thymomas and to further identify the relationship between PMG and prognosis.

METHODS

Thymoma patients who had surgery at the First Affiliated Hospital of Sun Yat-sen University between July 2004 and July 2016 were reviewed and those who had no previous symptoms of myasthenia gravis were selected for further investigation. In total, 229 patients were included in the study; their clinical characteristics were gathered and analysed.

RESULTS

Among the 229 patients, 19 (8.3%) had PMG. The time between the operation and the onset of myasthenia gravis was 134 days on average (range 2-730 days). Patients experiencing PMG showed a lower rate of complete thymoma resection (73.7% vs 91.4%; P = 0.014) and total thymectomy (63.2% vs 82.9%; P = 0.035) compared with those who did not. Univariable and multivariable logistic regression revealed that thymomectomy [odds ratio (OR) 2.81, 95% confidence interval (CI) 1.02-7.77; P = 0.047] and incomplete tumour resection (OR 3.79, 95% CI 1.20-11.98; P = 0.023) were associated with the occurrence of PMG. Multivariable Cox regression showed that the PMG was not related to overall survival (P = 0.087).

CONCLUSIONS

This study revealed that incomplete tumour resection and thymomectomy were independent risk factors for PMG in thymoma patients with no previous history of myasthenia gravis.

Intermediate oncologic outcomes after uniportal video-assisted thoracoscopic thymectomy for early-stage thymoma

Background

Recent years have seen a trend towards utilizing a video-assisted thoracic surgery (VATS) approach for treatment of thymoma. Although increasing in practice, intermediate- and long-term oncologic outcome data is lacking for the VATS approach. There is no oncologic data for the uniportal VATS approach. We sought to evaluate the feasibility and impact on patient survival of uniportal VATS thymectomy for early-stage thymoma.

Method

The clinical outcomes for 17 patients with Masaoka stage I to II thymomas treated between January of 2009 and July of 2014 at a single institution were collected retrospectively. Primary endpoint was overall survival (OS) and secondary endpoint was recurrence-free survival (RFS).

Results

Ten women and seven men underwent uniportal VATS thymectomy; eleven had stage I thymoma and six had stage II thymoma. There were no conversions to open surgery. Operative mortality was zero. Mean tumor size was 3.8±1.0 centimeters, with a range of 1.9 to 6.0 centimeters. All patients underwent a R0 resection. Five-year survival was 100%, and the estimated RFS was 100%.

Conclusions

Our findings suggest that uniportal VATS thymectomy for early-stage thymoma is feasible, and the intermediate-term oncologic outcomes are comparable to historic standards for open and multi-incision VATS thymectomy. However, additional follow-up is required to evaluate for long-term oncologic outcomes.

Genomic profiling of thymoma using a targeted high-throughput approach

Introduction

Thymomas and thymic carcinoma (TC) are the most common neoplasms localised in the thymus. These diseases are poorly understood, but progress made in next-generation sequencing (NGS) technology has provided novel data on their molecular pathology.

Material and methods

Genomic DNA was isolated from formalin-fixed paraffin-embedded tumour tissue. We investigated somatic variants in 35 thymoma patients using amplicon-based TruSeq Amplicon Cancer Panel (TSACP) that covers 48 cancer related genes. We also analysed three samples from healthy individuals by TSACP platform and 32 healthy controls using exome sequencing.

Results

The total number of detected variants was 4447, out of which 2906 were in the coding region (median per patient 83, range: 2-300) and 1541 were in the non-coding area (median per patient 44, range: 0-172). We identified four genes, APC, ATM, ERBB4, and SMAD4, having more than 100 protein-changing variants. Additionally, more than 70% of the analysed cases harboured protein-changing variants in SMAD4, APC, ATM, PTEN, KDR, and TP53. Moreover, this study revealed 168 recurrent variants, out of which 15 were shown to be pathogenic. Comparison to controls revealed that the variants we reported in this study were somatic thymoma-specific variants. Additionally, we found that the presence of variants in SMAD4 gene predicted shorter overall survival in thymoma patients.

Conclusions

The most frequently mutated genes in thymoma samples analysed in this study belong to the EGFR, ATM, and TP53 signalling pathways, regulating cell cycle check points, gene expression, and apoptosis. The results of our study complement the knowledge of thymoma molecular pathogenesis.

Complex redo surgery to treat a large thymoma invading the right atrium

BACKGROUND AND AIM

Anterior mediastinal masses which invade the great vessels and heart are rare. We report a case of a 76-year-old male presenting with a large invasive anterior mediastinal mass following recent cardiac surgery (coronary artery bypass grafting and aortic valve replacement via sternotomy).

MATERIALS AND METHODS

This is a case report study with clinical patient information retrieved from hospital electronic records.

RESULTS

Computed tomography scanning revealed a large heterogeneous 6.5 × 7.2 × 7.0 cm right anterior mediastinal mass. The mass directly propagated via the left innominate vein into the superior vena cava (SVC) and proximal right atrium. The patient underwent redo sternotomy with the aid of cardiopulmonary bypass and hypothermic circulatory arrest to remove the mass. The mass was sitting in the right pleural cavity and was adherent to the right lung and pericardium. Tumor material was removed from the right atrium, SVC and left innominate vein. The mass was excised en bloc along with a portion of the upper lobe of the right lung.

DISCUSSION AND CONCLUSION

Histology of the mass revealed the diagnosis of invasive type A thymoma with transvenous and transcardiac invasion. We advocate for surgeons to be aggressive in their operative resection of such tumours to ensure the best prognostic outlook for the patient.

Treatment Outcome and Prognostic Factors of Malignant Thymoma - A Single Institution Experience

Objective:

Our objectives are to investigate the clinicopathological features, treatment modalities, and prognostic and prognostic factors in order to estimate long-term outcomes for patients with thymoma and thymic carcinoma at our institution.

Methods:

We reviewed all patients diagnosed with thymic malignancies malignancies over a period of 38 years (from 1976 to 2014). Patients were identified using a single institution database at King Faisal Specialist Hospital and Research Center (KFSH and RC), Riyadh. Demographic data, clinical staging, histopathology classification, treatment approaches, and survival data were collected. Data Analysis was performed using both the Kaplan–Meier method and Cox proportional hazards modeling.

Results:

The fifty-six identified patients consists of 30 females (53.6%) and 26 males (46.4%). The median age at diagnosis was 39 years. About 37% of the patients were diagnosed with myasthenia gravis (MG). There was a significant association between the WHO histologic classification and the Masaoka stage (p= 0.018). The estimated 5-year overall survival rate was 88.6% for patients with thymic malignancies. The median survival time of thymoma and thymic carcinoma was 61 and 14 months, respectively. The univariate analysis suggested that histology (thymoma versus thymic carcinoma, p= 0.044) and Masaoka stage (II-III versus IV, p= 0.048) were independent prognostic factors affecting overall survival. Histology (p = 0.044) was found to be an independent predictor of overall survival.

Conclusion:

The findings of this study indicates that late Masaoka-Koga staging and histology types are significantly associated with extended overall survival. Similarly, surgical resection and multimodality treatments play a significant role in thymic malignancies neoplasms therapy strategies to prolong survival rates.

A case of thymoma in myasthenia gravis: Successful outcome after thymectomy

INTRODUCTION

Thymic abnormalities occur as hyperplasia and thymoma. Myasthenia gravis is commonly present in thymoma. Thymectomy possesses risk due to anatomical proximity with vital thoracic structures and myasthenia crisis.

PRESENTATION OF CASE

Forty five years female with complaints of difficulty swallowing and weakness of upper limb muscles upon investigation showed mass in mediastinum and antibody test for myasthenia gravis positive. Medical management was done for a month followed by thymectomy. There were no intra and postoperative complications. Medical management was stopped one month after surgery and she is symptom free.

DISCUSSION

Thymectomy is the standard of care where median sternotomy is the mainstay approach to surgery. Various other surgical approaches and complications revolving around surgery has been discussed.

CONCLUSION

Surgical removal of thymoma cured myasthenia gravis in our case. We focused on proper preoperative optimization of myasthenia gravis symptoms before thymectomy.

CT imaging features of canine thymomas

Canine thymomas have been evaluated based on clinical features, treatment options, surgical excision, and outcomes with limited information on specific CT features. The objective of this retrospective, descriptive, cross-sectional study was to describe the CT characteristics of confirmed thymomas and to compare these imaging features to outcome. A total of 22 dogs met the inclusion criteria of histologically confirmed thymomas with concurrent CT imaging. Tumor size varied widely ranging from small and well-circumscribed to large and invasive. Delayed-phase, contrast-enhanced CT studies were best for determining the degree of contrast enhancement in tumors. Of these, 19 of 22 masses had heterogeneous enhancement and three of 22 masses had homogeneous enhancement. Vascular invasion was present in seven of 22 cases. Larger tumors were associated with vascular invasion (height: P = .04; width and volume: P = .02). On precontrast CT, larger tumors (16/21) were heterogeneous and cystic, with smaller tumors (5/21) being more homogeneous (all values P < .05). A larger size was associated with recurrence in fully resected masses (height: P = .03), but not a shorter outcome (P > .3 for all size dimensions). Postoperative complications and incomplete tumor resection were associated with shorter outcome (both values P < .01). Metastasis was confirmed in four cases. There were six cases with lymphadenopathy noted on CT; five of the six cases did not have evidence of metastasis. Larger tumors were more likely to be cystic and associated with vascular invasion.

Management of incidental anterior mediastinal lesions: summary of relevant studies

With the increasing use of chest computed tomography (CT) imaging, the detection of asymptomatic incidental lesions in the anterior mediastinum has become more frequent. The prevalence of incidental nodular lesions in the anterior mediastinum is 0.49% to 0.89%. Most of these lesions manifest as soft tissue nodules measuring between 10 and 30 mm on non-contrast CT images. Thymic epithelial tumors are mainly responsible for larger lesions, while smaller lesions are primarily benign cysts. Most incidental thymic epithelial tumors are early-stage and have a favorable outcome. During follow-up, most lesions are stable, but some show indolent growth. Incidental lesions can be managed by a conservative patient-tailored approach with regular follow-up and the use of non-invasive imaging modalities such as magnetic resonance imaging.

Signs heralding appearance of thymomas after extended thymectomy for myasthenia gravis

Purpose of review

Thymomas appear very rarely after extended thymectomy for early-onset myasthenia gravis (EOMG). We describe 2 such cases that highlight potential early warning signs.

Recent findings

In their 20s, one woman and one man developed EOMG (AChR antibody-positive), requiring extended transsternal removal of hyperplastic thymi at ages 35 and 27, respectively. Their myasthenia gravis was readily controlled for the next 10 and 7 years before deteriorating in both, with appearance of late clinical features and anticytokine autoantibodies suggesting underlying thymomas, namely respiratory infections, genital herpes, chronic candidiasis, and alopecia in the woman and erythroderma and lichen planus in the man, followed by Pseudomonas, Klebsiella, and cytomegalovirus infections plus chronic hepatitis during intensifying immunosuppressive therapy. Type B thymomas were then detected. Despite surgery or radiotherapy, and intensive drug therapy, the patients died 7 and 1 years later.

Summary

Certain infections/dermatologic manifestations that associate with long-standing thymomas may herald their late appearance, despite previous thymectomy.

Video-Assisted Thoracoscopic Versus Robotic-Assisted Thoracoscopic Thymectomy: Systematic Review and Meta-analysis

OBJECTIVE

Minimally invasive thoracic surgical procedures, performed with or without the assistance of a robot, have gained popularity over the last decade. They have increasingly become the choice of intervention for a number of thoracic surgical operations. Minimally invasive surgery decreases postoperative pain, hospital stay and leads to a faster recovery in comparison with conventional open methods. Minimally invasive techniques to perform a thymectomy include video-assisted thoracoscopic surgery (VATS) or robotic-assisted thoracoscopic surgery (RATS). In this study, we aim to systematically review and interrogate the literature on minimally invasive thymectomy and draw a meta-analysis on the outcomes between the two approaches.

METHODS

An extensive electronic health database search was performed on all articles published from inception to May 2015 for studies describing outcomes in VATS and RATS thymectomy.

RESULTS

A total of 350 patients were included in this study, for which 182 and 168 patients underwent RATS and VATS thymectomy, respectively. There were no recorded in-hospital deaths for either procedure. There was no statistical difference in conversion to open, length of hospital stay, or postoperative pneumonia. Operational times for RATS thymectomy were longer.

CONCLUSIONS

The VATS and RATS thymectomy offer good and safe operative and perioperative outcomes. There is little difference between the two groups. However, there is poor evidence basis for the long-term outcomes in minimally invasive procedures for thymectomy. It is imperative that future studies evaluate oncological outcomes both short and long term as well as those related to safety.

Inter-relationship among myasthenia gravis, WHO histology, and Masaoka clinical stage and effect on surgical methods in patients with thymoma: a retrospective cohort study

Background

The aim of study is to analyze the inter-relationship among WHO histology, myasthenia gravis (MG) and Masaoka stage and to assess the feasibility of thoracoscopic surgery in thymoma patients.

Methods

Data from 142 consecutive thymoma patients from January 2009 to March 2016 were retrospectively reviewed in our institution. Histological classification and clinical staging were assessed by WHO histology criteria and Masaoka stage. We investigated the clinical characteristics, inter-relationship among WHO histology, MG and Masaoka stage, and compared the feasibility and safety of thoracoscopic thymectomy by comparison of open thymectomy.

Results

Among 142 patients, the incidence of MG was 29.6%. Compared with A and AB-type thymomas, a higher prevalence of advance clinical stage was in B1 to C-type thymomas (37/63 vs. 9/43, P<0.001), and there was an increased trend of Masaoka stage from A to C-type thymomas (P<0.001). The incidence of MG was significantly higher in AB, B1 and B2-type thymomas than other type thymomas (23/63 vs. 6/44, P=0.009) and in early Masaoka clinical stage than advanced Masaoka clinical stage (29/80 vs. 12/59, P=0.042). Thoracoscopic surgery could significantly decrease blood loss in patients with (104.06±137.36 vs. 350.91±560.79 mL, P=0.001) or without MG (91.90±77.70 vs. 266.32±292.60 mL, P=0.02), with comparable complications. Additionally, thoracoscopic surgery could achieve an equal effect on the remission of MG with open surgery (7/11 vs. 10/14, P=1.000), and Masaoka stage was significantly associated with the remission of MG after thymectomy.

Conclusions

Our study suggests that WHO histology, MG, and Masaoka stage interrelate with one another, and Masaoka stage is an important prognostic factor in remission of MG after thymectomy in thymoma patients. Thoracoscopic thymectomy could achieve an equal efficacy to open thymectomy and should be recommended as a routine surgery for patients with early Masaoka stage.

Primary clear cell carcinoma of the thymus and literature comparison of features

Clear cell carcinoma arising from the thymus is considered exceedingly rare. It shows aggressive clinical behavior and demonstrates frequent local recurrences as well as widespread metastasis. The detailed clinical data of one patient with thymic clear cell carcinoma were compiled, and a review of relevant reported studies was performed. We summarized the clinical characteristics, pathological diagnosis of the patient and other reported cases. The analysis showed that older male patients were more likely to suffer, and the manifestations included chest pain and dyspnea. Some patients are asymptomatic, with the tumor being discovered during physical examination. Histologically, thymic clear cell carcinoma is composed of lobulated structures arranged in hyperchromatic fibrous stroma; the tumor cells are uniform with obvious nucleoli and clear cytoplasm. To establish the correct diagnosis, consideration and exclusion of metastasis and other original tumors in the differential diagnosis by immunohistochemistry, clinical and radiologic correlation is important.

Subxiphoid single incision thoracoscopic surgery approach for thymectomy: a case report

Thoracic surgery is rapidly evolving with minimally invasive strategies now dominating. Thymectomy has traditionally been performed through a sternotomy, but more recently video-assisted thoracoscopic surgery (VATS) approaches have become increasingly popular. To further minimise surgical impact, the uniportal subxiphoid VATS technique has recently been described, using a muscle sparing incision that avoids intercostal nerve injury. A potential advantage that makes this approach particularly suited to thymectomy includes the ability to access both sides of the chest with a single incision. There is also the potential for reduced post-operative pain and chronic thoracostomy neuralgia. Here we describe the management of a patient with thymoma, reporting our procedure and technique for performing uniportal subxiphoid VATS thymectomy.

Incidental Anterior Mediastinal Nodular Lesions on Chest CT in Asymptomatic Subjects

OBJECTIVE

The aim of this study was to investigate the prevalence and characteristics of nodular lesions in the anterior mediastinum that had been found incidentally on screening chest computed tomography (CT) in asymptomatic subjects.

METHODS

We included 56,358 consecutive participants (mean age 52.4 ± 10.5 years; male-female ratio 35,306:21,052) who underwent a baseline low-dose chest CT scan as part of a health checkup from 2006 through 2013. After the presence of anterior mediastinal nodular lesion had been confirmed, their CT findings, confirmatory diagnosis, and interval CT scan were reviewed. The standardized prevalence ratio for thymic epithelial tumor was calculated on the basis of the Republic of Korea cancer statistics for 2014.

RESULTS

Of the 56,358 participants, 413 (0.73%) had lesions (95% confidence interval: 0.66-0.80%); the prevalence increased with age (p <0.001) and a history of malignancy (p = 0.005). Of the lesions, 85.2% were smaller than 2 cm, 61.3% were round, and 80.2% had CT attenuation higher than 20 Hounsfield units. Among 51 proven cases, 39 lesions (76.9%) were benign and 12 (23.1%) were malignant. The standardized prevalence ratio for thymic epithelial tumor was 2.04 (95% confidence interval: 1.01-3.42). Of 11 resected thymic epithelial tumors, five were carcinomas, 10 were stage I or II, and all were completely resected without recurrence. Of the 237 unconfirmed cases with a follow-up CT scan, 82.2% were stable, 8.9% had increased, and the other 8.9% had decreased.

CONCLUSIONS

The prevalence of incidental nodular lesion was 0.73%. Most lesions had CT features that were indistinguishable from thymic epithelial tumors, but a considerable portion of the lesions were suspected to be benign. Incidental thymic epithelial tumors were more prevalent than clinically detected tumors, were early-stage cancer, and showed favorable outcomes.

Ectopic thymoma managed by neck dissection & video-assisted thoracoscopic thymectomy

Ectopic thymoma in the neck is a rare phenomenon, with fewer than 20 cases reported worldwide. Evidence for management of ectopic thymoma comes from literature for mediastinal thymoma despite clinical features that distinguish the two. Here we present a case of a 31-year-old female with an asymptomatic neck mass who was found to have an ectopic cervical thymoma with concomitant mediastinal thymic hyperplasia. The decision was made to perform a left-sided neck dissection and a video-assisted thoracoscopic surgery (VATS) thymectomy. We suggest that this approach be considered for a minimally invasive management of this rare but important condition.

Uniportal subxiphoid video-assisted thoracoscopic approach for thymectomy: a case series

Background

Minimally invasive techniques are becoming increasingly popular in thoracic surgery. Although median sternotomy is the traditional approach for thymectomy, video-assisted thoracoscopic surgery (VATS) approaches now predominate. This study reports a case series of the novel uniportal subxiphoid-VATS approach to extended thymectomy.

Methods

Over the period of study (October 2014-January 2017) 17 patients underwent uniportal subxiphoid-VATS extended thymectomy for a thymic nodule at the Shanghai Pulmonary Centre. Ten patients were female, and the mean age of the cohort was 55 years. The mean size of nodule was 23.6 mm.

Results

The mean operative duration was 2.5 hours, with one conversion to thoracotomy for bleeding. The mean operative blood loss was 115 mL. The median length of hospital stay was 4 days. There were no episodes of phrenic nerve palsies. The 30-day survival was 100%.

Conclusions

Uniportal subxiphoid-VATS is a feasible and safe surgical approach to extended thymectomy in selected patients, with good post-operative outcomes.

Robotic versus thoracoscopic thymectomy: The current evidence

BACKGROUND

The purpose of this study was to analyze all relevant comparative studies comparing robot-assisted minimally invasive thymectomy (RATS) and video-assisted thoracic surgery thymectomy (VATS) in terms of surgical and short-term outcomes.

METHODS

A systematic search for articles describing robot-assisted and video-assisted thymectomy and addressing surgical outcomes, operation time, length of hospitalization, intra-operative blood loss, conversion to sternotomy and post-operative complications was performed using the medical databases.

RESULTS

Of the 478 studies from preliminary screening, five articles were included. By pooling these studies, we found no significant differences between the RATS and VATS (odds ratio 1.24 (95% CI 0.51, 3.03; p = 0.63)).There were no significant differences in comparison of conversion rates, operation time (26.29 min (95% CI -2.57, 55.35; p = 0.07)) and length of hospitalization (-1.58 days (95% CI -4.78, 1.62; p = 0.33)). There was a slightly higher blood loss in the RATS group.

CONCLUSION

Our meta-analysis did not detect any statistically significant differences in surgery outcomes between the two groups.

Video-assisted thoracoscopic completion thymectomy based on mediastinal pleura guidance

We describe a practical video-assisted thoracoscopic surgery (VATS) technique for the en bloc resection of the thymoma, thymus, and bilateral mediastinum lipid based on mediastinal pleura guidance. By taking advantage of single-lumen endotracheal tube (SLET) anesthesia and artificial pneumothorax, we acquired excellent exposure of the anterior mediastinum operative field. In addition, our limited data showed that this surgical approach might have a potential tendency on reducing the blood loss and the operative times. Moreover, no complication of phrenic nerve paralysis or signs of myasthenia gravis were observed at the 6-month follow-up.

[Role of Postoperative Radiotherapy for Stage I/II/III Thymic Tumor - Results of the ChART Retrospective Database]

背景与目的

胸腺肿瘤术后放疗尚存在争议，此研究目的为评价术后放疗在Ⅰ期-Ⅲ期胸腺肿瘤中的作用。

方法

搜索中国胸腺瘤研究协作组（Chinese Alliance of Research for Thymomas, ChART）数据库中1994年至2012年接受手术切除未行新辅助治疗的Ⅰ期-Ⅲ期胸腺肿瘤患者的资料。对临床病理资料进行单因素、多因素分析，Cox比例风险模型用于决定死亡风险比。

结果

ChART数据库中Ⅰ期-Ⅲ期胸腺肿瘤共1, 546例。其中649例（41.98%）接受术后放疗。术后放疗与性别、组织学类型（World Health Organization, WHO）、胸腺切除程度、是否完全切除、Masaoka-Koga分期及辅助化疗相关。手术后辅助放疗患者5年、10年总生存和无瘤生存分别为90%和80%、81%和63%，而单纯手术者5年、10年总生存和无瘤生存分别为96%和95%、92%和90%，两组生存有统计学差异（P=0.001, P＜0.001）。单因素表明年龄、组织学分类（WHO）、Masaoka-Koga分期、是否完全切除和术后放疗与总生存相关。多因素分析提示组织学分类（WHO）（P=0.001）、Masaoka-Koga分期（P=0.029）和是否完全切除（P=0.003）是总生存的独立预后因素。单因素分析表明性别、重症肌无力、组织学分类、Masaoka-Koga分期、手术方式、术后放疗和是否完全切除与无瘤生存相关。多因素分析表明组织学类型（P＜0.001）、Masaoka-Koga分期（P=0.005）和是否完全切除（P=0.006）是无瘤生存的独立预后因素。亚组分析表明不完全切除患者接受术后放疗可以提高总生存和无瘤生存（P=0.010, P=0.017）。然而，完全切除者接受术后放疗则会降低总生存和无瘤生存（P＜0.001, P＜0.001）。

结论

此回顾性研究表明不完全切除Ⅰ期-Ⅲ期胸腺肿瘤患者术后放疗可以提高总生存和无瘤生存。但是，对于完全切除患者，术后放疗总体上并未显示出生存获益。

Superior vena cava reconstruction under the left internal jugular vein to left femoral vein bypass support

The complete surgical resection of malignant thymoma is recommended. We present a rare case of tumor resection and superior vena cava (SVC) reconstruction under veno-venous bypass support from the left internal jugular vein to the left femoral vein. The full amount of systemic heparinization (3 mg/kg) was avoided. The surgical pathology revealed thymic squamous cell carcinoma. No complications such as fatal extensive bleeding, coagulopathy, thromboembolism or transfusion reaction were found postoperatively. The patient was discharged home uneventfully. The support of this veno-venous bypass allows a safe and feasible thymic tumor resection and SVC reconstruction.

Giant thymoma successfully resected via hemiclamshell thoracotomy: a case report

Thymoma is an epithelial neoplasm of the thymus. It commonly lies in the anterior mediastinum and represents 20-30% of mediastinal tumours in adults. In this report we present a case of giant thymoma locating in the anterior-inferior mediastinum. A 46-year-old male came to our institute with slight pectoralgia and dyspnea. Chest CT shows a giant tumor measuring 19 cm × 16 cm × 15 cm in the left thoracic cavity. After careful examination, we performed surgery. At surgery, we found the tumor was adherent to left upper lobe of the lung, mediastinal pleura, and parietal pleural. The tumor was completely resected with combined resection of part left upper lobe of lung. The weight of the tumor was 2,135 g. Pathological diagnosis indicated a type AB thymoma according to the World Health Organization classification and a diagnosis of Masaoka stage IIB was made.

The role of postoperative radiotherapy for stage I/II/III thymic tumor-results of the ChART retrospective database

BACKGROUND

Postoperative radiotherapy (PORT) for thymic tumor is still controversial. The object of the study is to evaluate the role of PORT for stage I to III thymic tumors.

METHODS

The Chinese Alliance for Research in Thymomas (ChART) was searched for patients with stage I to III thymic tumors who underwent surgical resection without neoajuvant therapy between 1994 and 2012. Univariate and multivariate survival analyses were performed. Cox proportional hazard model was used to determine the hazard ratio for death.

RESULT

From the ChART database, 1,546 stage I to III patients were identified. Among these patients, 649 (41.98%) received PORT. PORT was associated with gender, histological type (World Health Organization, WHO), thymectomy extent, resection status, Masaoka-Koga stage and adjuvant chemotherapy. The 5-year and 10-year overall survival (OS) rates and disease-free survival (DFS) rates for patients underwent surgery followed by PORT were 90% and 80%, 81% and 63%, comparing with 96% and 95%, 92% and 90% for patients underwent surgery alone (P=0.001, P<0.001) respectively. In univariate analysis, age, histological type (WHO), Masaoka-Koga stage, completeness of resection, and PORT were associated with OS. Multivariable analysis showed that histological type (WHO) (P=0.001), Masaoka-Koga stage (P=0.029) and completeness of resection (P=0.003) were independently prognostic factors of OS. In univariate analysis, gender, myasthenia gravis, histological subtype, Masaoka-Koga stage, surgical approach, PORT and completeness of resection were associated with DFS. Multivariate analysis showed that histological subtype (P<0.001), Masaoka-Koga stage (P=0.005) and completeness of resection (P=0.006) were independent prognostic factors for DFS. Subgroup analysis showed that patients with incomplete resection underwent PORT achieved better OS and DFS (P=0.010, 0.017, respectively). However, patients with complete resection underwent PORT had the worse OS and DFS (P<0.001, P<0.001, respectively).

CONCLUSIONS

The current retrospective study indicates that PORT after incomplete resection could improve OS and DFS for patients with stage I to III thymic tumors. However for those after complete resection, PORT does not seem to have any survival benefit on the whole.

Management of large mediastinal masses: surgical and anesthesiological considerations

Large mediastinal masses are rare, and encompass a wide variety of diseases. Regardless of the diagnosis, all large mediastinal masses may cause compression or invasion of vital structures, resulting in respiratory insufficiency or hemodynamic decompensation. Detailed preoperative preparation is a prerequisite for favorable surgical outcomes and should include preoperative multimodality imaging, with emphasis on vascular anatomy and invasive characteristics of the tumor. A multidisciplinary team should decide whether neoadjuvant therapy can be beneficial. Furthermore, the anesthesiologist has to evaluate the risk of intraoperative mediastinal mass syndrome (MMS). With adequate preoperative team planning, a safe anesthesiological and surgical strategy can be accomplished.

Differentiating the grades of thymic epithelial tumor malignancy using textural features of intratumoral heterogeneity via (18)F-FDG PET/CT

OBJECTIVE

We aimed to explore the ability of textural heterogeneity indices determined by (18)F-FDG PET/CT for grading the malignancy of thymic epithelial tumors (TETs).

METHODS

We retrospectively enrolled 47 patients with pathologically proven TETs who underwent pre-treatment (18)F-FDG PET/CT. TETs were classified by pathological results into three subgroups with increasing grades of malignancy: low-risk thymoma (LRT; WHO classification A, AB and B1), high-risk thymoma (B2 and B3), and thymic carcinoma (TC). Using (18)F-FDG PET/CT, we obtained conventional imaging indices including SUVmax and 20 intratumoral heterogeneity indices: i.e., four local-scale indices derived from the neighborhood gray-tone difference matrix (NGTDM), eight regional-scale indices from the gray-level run-length matrix (GLRLM), and eight regional-scale indices from the gray-level size zone matrix (GLSZM). Area under the receiver operating characteristic curve (AUC) was used to demonstrate the abilities of the imaging indices for differentiating subgroups. Multivariable logistic regression analysis was performed to show the independent significance of the textural indices. Combined criteria using optimal cutoff values of the SUVmax and a best-performing heterogeneity index were applied to investigate whether they improved differentiation between the subgroups.

RESULTS

Most of the GLRLM and GLSZM indices and the SUVmax showed good or fair discrimination (AUC >0.7) with best performance for some of the GLRLM indices and the SUVmax, whereas the NGTDM indices showed relatively inferior performance. The discriminative ability of some of the GLSZM indices was independent from that of SUVmax in multivariate analysis. Combined use of the SUVmax and a GLSZM index improved positive predictive values for LRT and TC.

CONCLUSIONS

Texture analysis of (18)F-FDG PET/CT scans has the potential to differentiate between TET tumor grades; regional-scale indices from GLRLM and GLSZM perform better than local-scale indices from the NGTDM. The SUVmax and heterogeneity indices may have complementary value in differentiating TET subgroups.

Upregulated expression of NKG2D and its ligands give potential therapeutic targets for patients with thymoma

The activating receptor NKG2D (natural killer group 2, member D) of natural killer (NK) cells promotes tumor immune surveillance by targeting ligands selectively induced on cancer cells, and thus having an important role in antitumor immune response. Because these ligands are not widely expressed on healthy adult tissue, NKG2D ligands may present as useful target for immunotherapeutic approaches in cancer. In this study, to elucidate the role of NKG2D-NKG2D ligand interaction in thymoma tissues and to evaluate the potential role of NKG2D ligands as therapeutic target for thymoma, we examined the expression of NKG2D and its specific ligands: MICA (major histocompatibility complex class I chain-related protein A), MICB (major histocompatibility complex class I chain-related protein B) and ULBP (UL16-binding protein) in 36 thymomas (6 subtype A, 6 subtype AB, 8 subtype B1, 5 subtype B2, 6 subtype B3 and 5 subtype C), 15 thymic atrophy and 8 thymic hyperplasia by immunohistochemistry and reverse transcription-real-time-PCR methods. We demonstrated that both mRNA and protein levels of NKG2D, MICA, MICB and ULBP were upregulated in six types of thymomas compared with those in atrophic thymus or proliferating thymus. Furthermore, the NKG2D ligands were found to be frequently coexpressed on thymoma cells. Furthermore, the expression of MICA, MICB and ULBP in subtype C was higher compared with those in subtype A, AB, B1, B2 and B3. Thus, we concluded that high expressions of NKG2D, MICA, MICB and ULBP1 were shown in patients with thymoma, and this may enhance the recognition function of NK cells to eliminate tumor cells. MICA, MICB and ULBP presented an attractive target for thymoma therapy. The abnormal expression of NKG2D, MICA, MICB and ULBP1 can provide us with evidence of the occurrence of thymoma and could also be used as a target in the treatment of thymoma.

A phase II study of saracatinib (AZD0530), a Src inhibitor, administered orally daily to patients with advanced thymic malignancies

OBJECTIVES

Thymic malignancies are rare, and options are limited for metastatic disease. Src plays a role in normal thymic epithelial maturation, and its inhibition with the oral compound saracatinib was postulated to be effective in controlling thymic malignancy.

MATERIALS AND METHODS

Patients with unresectable thymic malignancy were treated with saracatinib 175mg by mouth daily in 28 days cycles with radiographic evaluation at cycle 2 day 1 for safety, then cycle 3 day 1 and every 8 weeks thereafter. Response was evaluated by RECIST 1.0. A two-stage optimal design was used, powered to detect a true response rate of 20%.

RESULTS

21 patients were enrolled at two institutions, 12 of them with thymoma, 9 with thymic carcinoma. Thymoma patients received a median of 4.5 cycles and thymic carcinoma patients a median of 1 cycle. There were no responses, so accrual was halted after the first stage per protocol. 9 patients had stable disease beyond the first assessment. Median time to progression was 5.7 months for thymoma patients and 3.6 months for thymic carcinoma patients. Saracatinib was well tolerated.

CONCLUSION

Src inhibition by saracatinib did not produce any radiographic responses, though some patients did experience stable disease. Though negative, this study shows the feasibility of completing a trial in this rare disease, and of accruing reasonably significant numbers of thymic carcinoma patients. More clinical trials are required for this population (NCT00718809).

Thymoma treated with 177Lu DOTATATE induction and maintenance PRRT

A 47-year-old man presented with a recurrent thymoma World Health Organization type A of the anterior chest wall with pleural metastases after failing chemotherapy. The tumor was positive on In-octreotide, and he was referred for peptide receptor radionuclide therapy (PRRT) with Lu DOTATATE. He received 4 induction and 2 maintenance Lu DOTATATE treatments (total dose, 1000 mCi) and reported significant improvement in symptoms. Before the seventh treatment, mild progression was diagnosed on CT, and PRRT was terminated. The use of induction and maintenance Lu DOTATATE PRRT therapy in the management of thymoma warrants further research.

GLI1, CTNNB1 and NOTCH1 protein expression in a thymic epithelial malignancy tissue microarray

BACKGROUND/AIM

Thymic epithelial tumors (TET) are rare. Wingless and INT (WNT), NOTCH and sonic hedgehog pathway interactions between thymocytes and thymic stroma are important to thymus and T-cell development. We analyzed a thymoma tissue microarray (TMA) for glioma associated oncogene homolog 1 (GLI1), NOTCH1 and catenin (cadherin-associated protein, beta 1) (CTNNB1) expression as surrogate markers of sonic hedgehog, NOTCH and WNT pathway activity.

MATERIALS AND METHODS

GLI1, NOTCH1 and CTNNB1 expression were assayed in a tissue microarray of 68 TET and eight benign thymus by fluorescent immunohistochemistry (AQUA) as surrogates for activity of the sonic hedgehog, NOTCH and WNT pathways respectively.

RESULTS

No difference in tumor GLI1 (mean 201 vs. 211, p=0.31), CTNNB1 (mean 222 vs. 306, p=0.66) or NOTCH1 expression (mean 317 vs. 325, p=0.82) was noted between thymic tumor and benign thymus.

CONCLUSION

No evidence for preferential expression of GLI1, NOTCH1 or CTNNB1 was noted. High-throughput immunofluorescence using AQUA technology can help overcome limitations of small sample size and tissue heterogeneity when analyzing protein expression in thymic tumors.

Comparative study of video-assisted thoracic surgery versus open thymectomy for thymoma in one single center

BACKGROUND

Due to the popularity of video-assisted thoracic surgery (VATS) techniques in clinical, thymoma patients via VATS thymectomy are increasing rapidly. However, compared with open thymectomy, the potential superiorities and defects of VATS thymectomy remain controversial.

METHODS

A number of 129 patients who underwent thymectomy of early stage thymoma (Masaoka stage I and stage II) in one single center from January 2007 to September 2013 were selected in this retrospective study. Of those patients, 38 thymoma patients underwent VATS thymectomy (VATS group) and 91 underwent open thymectomy (open group) via either transsternal [44] or transthoracic approach [47] in the same period. The postoperative variables, which included postoperative hospital length of stay (LOS), the intensive care unit (ICU) LOS, the entire resection ratio, the number of thoracic drainage tubes, the quantity of output and duration of drainage, were analyzed. Meanwhile, the operation time and blood loss were considered as intraoperative variables.

RESULTS

All thymoma patients in the analysis included 19 thymoma patients with myasthenia gravis, among which five patients via VATS thymectomy and 14 patients via open thymectomy respectively. There was no death or morbidity due to the surgical procedures perioperatively. The ICU LOS, operation time, entire resection ratio, and the number of chest tubes were not significantly different in two groups. The postoperative hospital LOS of VATS thymectomy was shorter than that of open thymectomy (5.26 versus 8.32 days, P<0.001). The blood loss of VATS thymectomy was less than open thymectomy (114.74 versus 194.51 mL, P=0.002). Postoperatively, the quantity of chest tubes output in VATS group was less than that in open thymectomy group (617.86 versus 850.08 mL, P=0.007) and duration of drainage in VATS group was shorter than that in open thymectomy group (3.87 versus 5.22 days, P<0.001).

CONCLUSIONS

VATS thymectomy is a safe and practicable treatment for early-stage thymoma patients. Thymoma according with Masaoka staging I-II without evident invading seems to be performed through VATS approach appropriately, which has shorter postoperative hospital LOS, less blood loss and less restrictions to activities, hence patients will recover sooner.

Management of thymic tumors: a European perspective

Thymic tumors are rare mediastinal tumors, which are considered as orphan diseases due to their low prevalence. The most recent histologic classification divides thymic tumors into thymomas, thymic carcinomas (TC) and neuroendocrine thymic tumors (NETT). Until recently, clinical research on thymic tumors has been primarily represented by single-institution experiences usually scattered over a long time period in order to accumulate a sufficient number of patients for clinical analysis. Europe has played a pivotal role in the advancement of the clinical research on thymus in the past years. In the last decade, there has been an increased interest in thymic malignancies in the scientific community. The European Society of Thoracic Surgeons (ESTS), the most representative society of general thoracic surgeons in the world, established a dedicated thymic working group in 2010 with the intent to provide a platform among ESTS members with a specific interest in thymic malignancies. The present review is intended to provide, through the description of the activity of the ESTS thymic working group and its published results, an overview of the European contribution to the thymic research. A brief overview of the state-of-the-art of clinical presentation, diagnosis, staging and histologic classification of thymic tumors is also provided, along with the most recent therapeutic advancements.

Docetaxel-based chemotherapy as second-line regimen for advanced thymic carcinoma

Thymic carcinoma is an uncommon neoplasm. The efficacy of second-line treatment with docetaxel in advanced thymic carcinoma has not been well studied. Therefore, we conducted a review of the efficacy of docetaxel-based chemotherapy as a second-line regimen for advanced thymic carcinoma. Fifteen patients with advanced thymic carcinoma who received second-line chemotherapy with docetaxel singlet or docetaxel/platinum combination chemotherapy regimens were retrospectively reviewed. There were 11 males and four females, with a median age of 53 years. Squamous cell carcinoma was most common (n = 10), followed by undifferentiated carcinoma (n = 4), and small cell carcinoma (n = 1). Eight patients received docetaxel/platinum combination chemotherapy and seven docetaxel mono-therapy. Four patients showed partial responses, representing a response rate of 26.7%. The median progression-free survival and overall survival in the 15 patients were 4.0 (2.8-5.2) and 22.0 (14.6-29.4) months, respectively. There was no difference in progression-free survival between the docetaxel singlet or docetaxel/platinum combination chemotherapy (3.5 months vs. 4.0 months, P = 0.889). A docetaxel-based regimen could be a potential therapeutic option as a second-line chemotherapy for advanced thymic carcinoma.

Thymic neoplasms: an update on the use of chemotherapy and new targeted therapies. A literature review

Thymic malignancies represent a wide range of clinical, histological and molecular entities, with probably considerable heterogeneity even among tumors of the same histotype. Systemic chemotherapy with cisplatin-based regimens continues to represent the standard of care in metastatic or inoperable refractory/recurrent diseases and ADOC regimen (including cisplatin, doxorubicin, vincristine and cyclophosphamide) demonstrated the longer overall response rate and median survival in the first line setting, although no randomized trial is available; and there is still a lack of standard treatment after first-line failure. To date research efforts are focused on translational studies on molecular pathways involved in thymic tumors carcinogenesis, aimed to better understand and predict the efficacy of chemotherapy and targeted therapy. Recent molecular characterization includes identification of a number of oncogenes, tumor suppressor genes, chromosomal aberrations, angiogenic factors, and tumor invasion factors involved in cellular survival and proliferation and in tumor growth. The use of biologic drugs is currently not recommended in a routine practice because there are limited data on their therapeutic role in thymic epitelial tumors. Because of the lack of data from adequate-sized, prospective trials are required for validation and the enrolment of patients with advanced disease into available clinical trials has to be encouraged.

Histologic and immunohistochemical characterization of thymic epithelial tumours in the dog

Thymic epithelial tumour (TET) histologic subclassification has not been well described in the veterinary literature as it has in humans. The objective of this study was to identify and describe TET subtypes in dogs and to determine the utility of immunohistochemistry (IHC) in differentiating these subtypes. Samples were reviewed and classified according to a modified World Health Organization (WHO) criteria for human tumours of thymic origin. Signallment, presenting signs, treatment and survival data was collected from medical records. Histologic review confirmed the same subtypes as described in humans. Presence of high stage disease, pleomorphism, mitotic figures and capsular invasion was more common in atypical thymomas and thymic carcinomas than in thymomas. IHC was performed for GLUT-1, CD5, CD117 and CK8/18; however, this was not useful in classifying the tumours.