Vascular Involvement in Thymic Epithelial Tumors: Surgical and Oncological Outcomes

Role of Cine-Magnetic Resonance Imaging in the Assessment of Mediastinal Masses with Uncertain/Equivocal Findings from Pre-Operative Computed Tomography Scanning

BACKGROUND

Malignant neoplasms originating from or involving the mediastinum represent a diagnostic and therapeutic challenge when they are in contact with nearby cardiovascular structures. We aimed to test the diagnostic accuracy of cine-magnetic resonance imaging (cine-MRI) in detecting the infiltration of cardiovascular structures in cases with uncertain or equivocal findings from contrast-enhanced Computed Tomography (CT) scanning.

METHODS

Fifty patients affected by tumors with a suspected invasion of mediastinal cardiovascular structures at the pre-operative chest CT scan stage underwent cine-MRI before surgery at our Institution. Intraoperative findings and the histological post-surgical report were used as a reference standard to define infiltration. Inter- and intra-observer agreement for CT scans and cine-MRI were also computed over a homogenous sample of 14 patients.

RESULTS

Cine-MRI had a higher negative predictive value (93% vs. 54%, p < 0.001) than CT scans, higher sensitivity (91% vs. 16%, p < 0.001), as well as greater accuracy (66% vs. 50%, p < 0.001) in detecting cardiovascular invasion. Cine-MRI also showed better inter- and intra-observer agreement for infiltration detection.

CONCLUSIONS

Cine-MRI outperforms conventional contrast-enhanced chest CT scans in the preoperative assessment of cardiovascular infiltration by mediastinal or pulmonary tumors, making it a useful imaging modality in the preoperative staging and evaluation of patients with equivocal findings at the chest CT scan stage.

Internal jugular vein pressure monitoring guided venous reconstruction could improve perioperative safety after superior vena cava resection for mediastinal tumors: a cohort study

INTRODUCTION

After superior vena cava (SVC) resection, the decision on unilateral or bilateral reconstruction was mostly based on the expertise of surgeons without objective measurements. This study explored the use of internal jugular vein pressure (IJVP) monitoring to guide the SVC reconstruction strategy.

METHODS

In a retrospective cohort, perioperative outcomes of unilateral and bilateral reconstruction based on surgeons' experience were compared. Then, IJVP threshold was measured when temporarily clamping the left innominate vein in a testing cohort. Venous reconstruction according to IJVP monitoring was performed in a prospective validation cohort afterward. Perioperative outcomes were compared between the prospective and the retrospective cohorts. For some interested variables, intuitive explanations would be given using Bayesian methods. Potential risk factors for postoperative complications were investigated by multivariable analysis.

RESULTS

From March 2009 to September 2022, 57 patients underwent SVC reconstruction based on surgeons' experience. Bayesian analysis indicated a posterior probability of 80.49% that unilateral reconstruction had less blood loss than bilateral reconstruction (median 550 ml vs. 1200 ml). Cerebral edema occurred in two patients after unilateral reconstruction. In the testing cohort, median IJVP was 22.7 (18-27) cmH 2 O after temporary left innominate vein clamping in 10 patients. In the prospective cohort, unilateral reconstruction only was performed if the contralateral IJVP was <30 cmH 2 O in 16 patients. Bilateral reconstruction was performed if IJVP was ≥30 cmH 2 O after unilateral bypass in nine patients. No cerebral edema occurred in the prospective cohort. Less postoperative complications occurred in the prospective cohort than the retrospective cohort (12.0 vs. 38.6%, P =0.016). Upon multivariable analysis, IJVP-monitoring guided SVC reconstruction was associated with significantly less postoperative complications ( P =0.033).

CONCLUSIONS

Intraoperative IJVP-monitoring is a useful strategy for selection of unilateral or bilateral SVC reconstruction and improving perioperative safety in patients with mediastinal tumors.

Long term outcome of complex surgical resection and reconstruction for rare thoracic cancers

BACKGROUND

Complex surgical resection and reconstruction for rare thoracic cancers (RTCs) represent a major challenge, given their very low frequency, extreme variability of presentation, multi-modality treatment options and inadequate outcome prediction. We analysed the experience of a tertiary referral centre on a consecutive series of patients with thoracic germ cell tumours, thymomas and sarcomas, with the aim of reporting the long-term outcome by cancer type and complexity of surgical procedures.

METHODS

From Jan 2003 to Dec 2018, 768 surgical procedures were performed with curative intent on 644 RTC patients. Study endpoints were: post-operative hospital stay (Pod), 30-day and 90-day mortality, 5-year and 10-year overall survival (OS). Median follow-up of alive patients was 7.2 years.

RESULTS

Median Pod was 7 days, with a 1.2% 30-day and 2.9% 90-day mortality. OS was 90.8% at one year, 74.2% at five years and 62.8% at 10 years. Ten-year OS was 73.0% in low, 65.3% in intermediate, and 55.6% in high complexity score (Log-rank tests p<0.0001); 66.6% in patients with one or two reconstructions and 46.4% in patients with three or more reconstructions (p<0.0001); 46.0% with vascular and 50.0% with chest wall reconstruction; 71.8% in germ cell tumours, 64.6% in thymoma and 51.3% in sarcoma (p<0.0001).

CONCLUSION

Complex surgical resection and reconstruction was associated with acceptable 90-day mortality and good 10-year survival in all RTC types. A predictive score based on surgical complexity and cancer type can help the clinical decision making.

Significance of the Surgical Treatment with Lymph Node Dissection for Neuroendocrine Tumors of Thymus

BACKGROUND

Neuroendocrine tumors of a thymus (NETTs) are rare, accounting for approximately 2-5% of all thymic epithelial tumors, and have a poor prognosis due to frequent lymph nodes or distant metastasis.

METHODS

We retrospectively reviewed the clinicopathological background and outcomes of 40 patients who underwent resection or surgical biopsy with histologically diagnosed NETTs from 1986 to 2022.

RESULTS

The most common pathological type was atypical carcinoid. Surgical resection was performed in 35 patients, with lymph node dissection in 33 and surgical biopsy in five. The overall survival (OS) rate for all patients was 81.4% and 52.3% at 5 and 10 years, respectively. The 2-year survival rate was 20% for the biopsy group, which was significantly worse than that of the resected group (p < 0.001). The relapse-free survival rates were 61.7% and 37.6% at 5 and 10 years, respectively, in 34 patients with complete resection. The univariate analysis revealed better the OS rate in the resected cases but with no significant differences between histological grade, lymph node metastasis, tumor size, or Ki67 index.

CONCLUSIONS

Surgical complete resection is considered to improve prognosis regardless of histologic type. NETTs frequently develop lymph node metastasis, thus, lymph node dissection seems necessary for complete resection.

A Single Center Analysis of Thymic Neuroendocrine Tumors

Simple Summary

Thymic neuroendocrine tumors are extremely rare and therefore few published studies currently exist. This study sought to investigate the basic clinical characteristics, treatment and prognosis of TNETs using single-center retrospective data and to address this gap in the literature. We found that thymic neuroendocrine tumors are a rare and aggressive disease with a high recurrence rate even in typical carcinoid tumors that are usually considered to have a good prognosis, with local recurrence and bone metastases being a common mode of treatment failure. Despite the widely accepted view that surgical resection should be the treatment of choice for thymic neuroendocrine tumors, we found that combination therapy including radiotherapy and chemotherapy is necessary to address the high recurrence rate of this typically aggressive tumor. In addition, patients who suffered from large vessel invasion in our study had a lower rate of overall survival and a high risk of tumor progression, other therapeutic regimes should be explored for these patients.

Abstract

Purpose: Thymic neuroendocrine tumors (TNETs) are a collection of slow-progressing neoplasms located in the anterior mediastinum. Relatively few previously published studies have focused on thymic carcinomas. This study investigated the basic clinical characteristics, treatment, and prognosis of TNETs. Methods: Patients were enrolled in the study from January 2003 to December 2017 who had been diagnosed with TNETs through pathological screening and treated at our institution. Demographic data from each patient, the Masaoka stage, histology and size of the tumor, tumor invasion characteristics, and therapeutic strategies were gathered. The Kaplan–Meier method was used to assess patient survival. In addition, the log-rank test was used to carry out univariate analyses. Results: Twenty-six patients were eligible for inclusion in the study. The median age of the patients was 46.5 (25–69) years. The tumor median maximum diameter was 7.9 cm (from 3 to 19 cm). Twenty-four patients were treated surgically. Nineteen patients completed radiation therapy, and sixteen patients underwent chemotherapy. A median follow-up time of 54.95 months was observed. The survival rate for three years was 75.0% and 70.6% for five years. The corresponding progression-free survival rates for three and five years were 55.7% and 37.7%, respectively. The local, regional recurrence-free survival (LRFS) rates were 87.2% and 81.7%, and the distant metastasis-free survival (DMFS) rates were 55.7% and 37.7%, at three and five years, respectively. Local recurrence (six patients) and bone metastasis (six patients) were observed as the most frequent failures. Conclusion: TNET was observed to be an aggressive but rare malignant lesion. While the predominant treatment was complete resection, chemotherapy and radiotherapy were also required due to the high recurrence rate.

Thymomas With Intravascular and Intracardiac Growth

Thymomas are derived from the epithelial component of the thymus and constitute the most common tumor of the anterior mediastinum. These neoplasms are considered malignant for their potential for invasion and metastases. Several histopathologic subclassification schemes have been proposed over the years, however, correlation of histotypes with prognosis remains controversial. In contrast, studies invariably have shown that staging and resection status correlate with oncologic behavior and disease outcomes. In this regard, several staging systems have been presented, though transcapsular invasion and degree of involvement of adjacent anatomic structures are common denominators of all schemes. Involvement of the great vessels and heart most commonly results from direct invasion, which may lead to unusual clinical presentations such as superior vena cava syndrome. Moreover, intravascular and intracardiac growth with or without direct mural invasion rarely occurs. We provide an overview of thymomas with intravascular and intracardiac involvement.

Real-world clinicopathological features and outcome of thymic neuroendocrine tumors: a retrospective single-institution analysis

Background

Thymic neuroendocrine tumors comprise a heterogeneous group of rare diseases. This study aimed to investigate the real-world clinicopathological features and treatment outcomes of thymic neuroendocrine tumors.

Results

A total of 104 patients diagnosed with thymic neuroendocrine tumors in a single institution from 1983 to 2021 were eligible. Fourteen (13.46%) and 28 (26.92%) patients diagnosed with thymic neuroendocrine tumors suffered from multiple endocrine neoplasia and ectopic adrenocorticotropic hormone syndrome, respectively. Ninety-seven (93.27%) patients underwent surgical resection, including 79 (81.44%) with radical resection. Except for 5 patients lost during follow-up, the 1-, 3- and 5-year overall survival rates were 91.8%, 70.2% and 54.6%, respectively. The median overall survival was 61.57 months. Multivariate analysis revealed that years at diagnosis (HR 0.559, 95% CI 0.364–0.857, p = 0.008), radical resection (HR 2.860, 95% CI 1.392–5.878, p = 0.004), pathological grade (HR 1.963, 95% CI 1.058–3.644, p = 0.033) and Masaoka–Koga stage (HR 2.250, 95% CI 1.548–3.272, p = 0.000) exerted significant differences in overall survival among 99 patients. In the surgery group, multivariate Cox regression analysis exhibited significant overall survival differences in years at diagnosis (HR 0.563, 95% CI 0.367–0.866, p = 0.009), neoadjuvant therapy (HR 0.248, 95% CI 0.071–0.872, p = 0.030), radical resection (HR 3.674, 95% CI 1.685–8.008, p = 0.001), pathological grade (HR 2.082, 95% CI 1.098–3.947, p = 0.025) and Masaoka–Koga stage (HR 2.445, 95% CI 1.607–3.719, p = 0.000).

Conclusions

Radical resection and Masaoka–Koga stage were independent prognostic factors for the survival of patients with thymic neuroendocrine tumors. Systemic therapy and integrated management of patients with advanced-stage disease require high-level clinical evidence.