Mediastinal Research Articles

The Posteromedial-Transseptal Portal for Arthroscopic Suture Hook Repair of Posterior Horn Tears and Popliteomeniscal Fascicles Tears of the Lateral Meniscus

We present a convenient and safe arthroscopic technique for suturing the lateral meniscus. In this technique, the clinician establishes a conventional posteromedial approach in the figure-of-four position of the knee by using the anterolateral and anteromedial observation approaches. Behind the posterior cruciate ligament, an operational approach is formed through the posterior mediastinum of the knee joint. Through this approach, suture hook can be brought to the posterior horn and body of the lateral meniscus, thus simplifying the suture of the lateral meniscus. We have used this technique to finish all-inside suture using suture hooks in a variety of types of lateral meniscal injuries, including longitudinal posterior horn tears, bucket handle meniscus tears, and tears around the popliteal hiatus area. Compared with traditional lateral meniscal all-inside suture technology through anteromedial or anterolateral approaches, this technology can suture more accurately, safely, and conveniently, avoid the involvement of the popliteal tendon suture, and the lower risk of complications such as popliteal vascular and nerve injury occur.

Prognostic factors in patients with thymoma who underwent surgery

PurposeThymoma is the most common primary tumor in the anterior mediastinum. The prognostic factors of patients with thymoma still need to be clarified. In this study, we aimed to investigate the prognostic factors of patients with thymoma who received radical resection and establish the nomogram to predict the prognosis of these patients.Materials and methodsPatients who underwent radical resection for thymoma with complete follow-up data between 2005 and 2021 were enrolled. Their clinicopathological characteristics and treatment methods were retrospectively analyzed. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method and compared by the log-rank test. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the independent prognostic factors. According to the results of the univariate analysis in the Cox regression model, the predictive nomograms were created.ResultsA total of 137 patients with thymoma were enrolled. With a median follow-up of 52 months, the 5-year and 10-year PFS rates were 79.5% and 68.1%, respectively. The 5-year and 10-year OS rates were 88.4% and 73.1%, respectively. Smoking status (P = 0.022) and tumor size (P = 0.039) were identified as independent prognostic factors for PFS. Multivariate analysis showed that a high level of neutrophils (P = 0.040) was independently associated with OS. The nomogram showed that the World Health Organization (WHO) histological classification contributed more to the risk of recurrence than other factors. Neutrophil count was the most important predictor of OS in patients with thymoma.ConclusionSmoking status and tumor size are risk factors for PFS in patients with thymoma. A high level of neutrophils is an independent prognostic factor for OS. The nomograms developed in this study accurately predict PFS and OS rates at 5 and 10 years in patients with thymoma based on individual characteristics.

Anterior mediastinal tracheostomy for severe tracheal stenosis in a child with severe motor and intellectual disabilities: a case report

BackgroundOwing to recurrent aspiration pneumonia and airway stenosis secondary to thoracic deformities, tracheostomy or laryngotracheal separation are often necessary in children with severe motor and intellectual disabilities. However, these procedures are associated with the risks of tracheal stenosis due to tracheal granulation and tracheoinnominate artery fistula formation. We report a case of a child with severe motor and intellectual disabilities treated with an anterior mediastinal tracheostomy.Case presentationThe patient was a 15-year-old boy with severe motor and intellectual disabilities due to intractable epilepsy. Due to thoracic deformity and tracheomalacia, the patient had a flattened and narrowed trachea. Accordingly, laryngotracheal separation was performed 4 months before admission to avoid aspiration pneumonia. Due to a common cold, the patient required frequent sputum suctioning, which exacerbated the tracheal stenosis. Bronchoscopy revealed tracheal stenosis 4–5 cm caudal to the tracheostomy site, tracheal mucosal ulcers, and pulsation of the innominate artery on the anterior wall of the trachea. We performed an anterior mediastinum tracheostomy to release the tracheal stenosis and prevent tracheoinnominate artery fistula formation.ConclusionsAnterior mediastinal tracheostomy has several advantages. Including sufficient release of bony compression, release of tracheal hyperextension, and relief of tracheal and innominate artery contact ensures a cannula-free tracheostomy, and there is no need to dissect the brachiocephalic artery. It is the procedure of choice in cases of head and neck malignancies requiring extensive tracheal resection and could be a good surgical option for severe tracheal stenosis and tracheoinnominate artery fistula in children with severe motor and intellectual disabilities.

Marginal calcification of thymoma: differences in the location of calcification indicate differences in the characteristics of thymomas.

Thymic epithelial tumors (TETs) are the most common tumors located in the anterior mediastinum. Calcification is sometimes observed in thymomas, especially in thymomas, and has been reported to be an indicator of the invasive behavior of thymomas. However, whether or not all calcification indicates invasive behavior is unclear. The present study therefore analyzed the location, size, and patterns of thymoma calcification and the relationships between calcification and clinicopathological factors and prognosis. We conducted a retrospective study among 77 thymoma patients who underwent surgery between January 2012 and May 2022 and analyzed the relationship between the location of calcification and clinicopathological findings. The patients were categorized into three groups: those with inner calcification of the tumor (group I), those with marginal calcification (group M), and those without any calcification (group N). Calcification was identified in 13 thymomas (16.9%) in group I (n=8) and group M (n=5). Group M included significantly more low-risk thymomas than the other groups (P=0.030). In low-risk thymomas, especially type AB thymoma, marginal calcification was observed more frequently than in other lesions. There were significant differences in age (P=0.024) and Masako-Koga stage (P=0.020) among the groups. In group I, younger patients and patients with advanced-stage disease were included. There were no significant differences in the rates of recurrence or the recurrence-free period among the groups. However, recurrence was not recognized in any members of group M. The location of calcification should be a point of focus in thymomas, and differences in the location of calcification indicate differences in the characteristics of thymomas.

Step-wise ligation of hilum vs mass ligation during lobectomy of the lung- is it time for a change?

The standard technique for lobectomy followed now is using the superior hilar approach and the bronchus first technique, where the pulmonary artery (PA) vessels are first divided. However, there are certain scenarios where adhesions or extensive lymphadenopathy at the hilum have distorted the vessels. Also, in case of tumors and fistulae, the bronchus and vessels may be in close proximity. Hence, it may be necessary to perform a mass ligation of the hilar structures. The separate dissection of the lobe's vein, artery, and airway forms the basis of lobectomy. The anterior approach, often known as the anterior mediastinum, is currently the most common. To our knowledge, there is limited data to compare the outcomes of step-wise ligation with mass ligation at the hilum for lobectomy. Hence we performed this study where we compared the step-wise with mass ligation of hilar structures during a lobectomy.

Novel HNRNPM::LEUTX fusion resulting from chromothripsis of chromosome 19 in a pediatric undifferentiated small round cell neoplasm.

Small round cell neoplasms comprise a diverse group of tumors characterized by a primitive/undifferentiated appearance. Although several entities are associated with recurrent gene fusions, many of these neoplasms have not been fully characterized, and novel molecular alterations are being discovered. Here, we report an undifferentiated small round cell neoplasm arising in the anterior mediastinum of a 17-month-old female. The tumor harbored a novel HNRNPM::LEUTX fusion resulting from chromothripsis of chromosome 19, which was identified by whole transcriptome sequencing, but not by targeted sequencing. The structural variations caused by the chromothripsis event also challenged the interpretation of the targeted sequencing findings. This report expands the spectrum of gene partners involved in LEUTX fusions and underscores the value of whole transcriptome sequencing in the diagnostic workup of undifferentiated small round cell tumors. It also highlights the interpretive challenges associated with complex genomic alterations. A careful evidence-based analysis of sequencing data along with histopathologic correlation is essential to ensure correct categorization of fusions.

Diagnosis and treatment of the giant malignant peripheral nerve sheath tumor in the anterior mediastinum: A case report

INTRODUCTION: Malignant peripheral nerve sheath tumor (MPNST) occurs in young and middle-aged people, more frequently in those with the genetic disease known as neurofibromatosis type 1 (NF1). Approximately, 50% of people with MPNST have NF1 and 13% of people with NF1 will get MPNST during their lifetime.
 CASE REPORT: A 30-year-old patient after surgery for MPNST of the right hip in 2013 was observed. In 2017, a relapse was detected, and combined treatment was performed, including surgical excision of the relapse and postoperative distance radiotherapy with a total focal dose of 66 Gy. In 2018, MPNST of the left femoral nerve was diagnosed, and the tumor was excised. In 2020, a chest X-ray diagnosed a single focus of localized opacity in the anterior mediastinum, adjacent to the right lung. Computed tomography (CT) was performed to further verify the neoplasm, which revealed a single hypodense focus in the anterior mediastinum, adjacent to the right lung. According to histological examination of a tumor biopsy obtained by transthoracic ultrasound-guided biopsy, MPNST was verified. Magnetic resonance imaging (MRI) with intravenous contrast enhancement, including real-time MRI, was performed to assess the invasion of the mass into soft tissues and vessels and to plan surgical treatment. The following surgeries were done: right thoracotomy, removal of a neoplasm of the anterior mediastinum with resection of the upper lobe of the right lung, and marginal resections of the lower lobe of the right lung. This case demonstrates a rare localization and non-standard instrumental diagnosis of mediastinal MPNST. Apart from CT scanning, the patient underwent MRI of the thoracic organs. MRI allows assessing the invasion of the neoplasm into the surrounding tissues. This cannot always be achieved by CT scans, including those with contrast enhancement. Invasion is an important component in the planning of further surgical treatment tactics.
 CONCLUSIONS: MPNST is a tumor with an aggressive course and a poor prognosis due to resistance to therapy. This clinical case demonstrates a rare localized MPNST with a recurrent course and metastases to the lungs. The current radiological methods, such as CT and MRI, may be used effectively both for diagnosing MPNST and determining the appropriate surgical access to the lesion and the extent of surgery.

Ectopic thyroid mass separately present in mediastinum and not a retrosternal extension: a rare case report

Retrosternal extension of goiter is one of the most common types of masses in the superior mediastinum. These types of goiters classically present with compressive symptoms such as dyspnoea, dysphonia, dysphagia, or sleep apnea. Surgical treatment with a total thyroidectomy and complete removal of the intrathoracic portion of thyroid is the gold standard treatment. These cervico-mediastinal lesions at times may not be continuous, and a sternotomy may be required for complete and safe excision of the mediastinal mass to achieve decompression of the surrounding structures and preventing the hemorrhagic complications if attempted from cervical incision.

Preoperative neoadjuvant chemoradiotherapy provides borderline resectable thoracic esophageal cancer with equivalent treatment results as clinically T3 thoracic esophageal cancer.

Because the optimal treatment strategy for borderline resectable (cT3br) thoracic esophageal cancer patients remains unclear, it is of great interest whether preoperative neoadjuvant therapy for cT3br could achieve results comparable to those seen with resectable T3 cancer (cT3r). We speculated that preoperative neoadjuvant chemoradiotherapy (NACRT) would be particularly effective in cT3br thoracic esophageal cancer patients and compared to cT3br and cT3r. Of 186 cT3 thoracic esophageal cancer patients treated with intended NACRT, 162 received radical esophagectomy. More than 97% were squamous cell carcinomas. Patients were partitioned into two groups according to whether invasion of adjacent organs was suspected (cT3br and cT3r). Treatment outcomes and survival were analyzed. Sixty-eight patients (36.6%) were classified as cT3br and 118 (63.4%) as cT3r. The cT3br group had significantly more tumors in the upper and middle mediastinum (p < 0.0001) and more cases with cM1 (lymph node) (p = 0.0104) than the cT3r group. In addition, the cT3br patients receiving esophagectomy exhibited a significantly lower pathological complete response rate than the cT3r patients (p = 0.0374). However, the R0 resection rate did not differ between the cT3br and cT3r patients (p = 0.0978), and the two groups treated with intended NACRT had similar 5-year overall (OS) and disease-specific survival (DSS) (p = 0.3831 and p = 0.9020). In addition, the incidence and patterns of recurrence did not differ between the cT3br and cT3r patients receiving esophagectomy (p = 0.8109 and p = 0.3128). Preoperative neoadjuvant chemoradiotherapy appears to be a promising treatment for patients with borderline resectable thoracic esophageal squamous cell carcinoma.

Metastatic Parathyroid Carcinoma: A Case Report

Parathyroid carcinoma is a rare clinical entity, characterized by its diagnostic difficulties. We report a case of a 58 year- old male who presented with a history of chronic hypercalcemia, the cervical ultrasound reported a deep left cervical mass, pushing back the left thyroid lobe and the trachea, oval in shape, with clear contours. The thoracic-abdominal-pelvic CT scan showed a left thyro ïd mass plunging into the posterior mediastinum with secondary bone lesions, the patient underwent a total thyroïdectomy with a diagnosis of parathyroid carcinoma on morphological and immunohistochemical studies, he was treated with first line chemotherapy with a good clinical and biological evolution. After the last course of chemotherapy, the patient presented bone pain resistant to analgesics with elevated hypercalcemia.

Anatomic patterns of anastomotic leaks after Ivor Lewis esophagectomy for cancer: Impact on management and outcomes

BackgroundAnastomotic leakage presentation after Ivor Lewis esophagectomy may vary on imaging. Such variations may influence anastomotic leakage management and outcomes. MethodsAll consecutive patients who underwent Ivor Lewis esophagectomy for cancer between 2012 and 2019 in 2 referral centers were included. Anatomical patterns of anastomotic leakage were defined on imaging as follows: eso-mediastinal anastomotic leakage was a leak contained in the posterior mediastinum, eso-pleural anastomotic leakage was a leak involving the pleural cavity, and eso-bronchial anastomotic leakage was a leak communicating with the tracheobronchial tract. According to the Esophageal Complications Consensus Group definition, management and 90-day mortality were evaluated according to these patterns. ResultsAmong 731 patients, 111 (15%) developed anastomotic leakage consisting of eso-mediastinal anastomotic leakage (n = 87, 79%), eso-pleural anastomotic leakage (n = 16, 14%) and eso-bronchial anastomotic leakage (n = 8, 7%). There was no difference among these groups regarding preoperative characteristics or time to anastomotic leakage diagnosis. There was a significant difference in initial management according to anastomotic leakage anatomic patterns (P = .001). More than half of patients who experienced eso-mediastinal anastomotic leakage (n = 46, 53%) were initially treated conservatively without requiring intervention (Esophageal Complications Consensus Group type I), whereas most patients with eso-pleural anastomotic leakage (n = 14, 87.5%) and all with eso-bronchial anastomotic leakage (n = 8, 100%) initially required interventional or surgical treatment (Esophageal Complications Consensus Group type II–III). Anastomotic leakage anatomic patterns had a statistically significant impact on 90-day mortality, intensive care unit stay, and total hospital stay (P < .001). ConclusionAnastomotic leakage anatomic patterns after Ivor Lewis esophagectomy influence outcomes. Further studies are warranted to validate it in a prospective setting. Anastomotic leakage anatomic patterns may help in guiding anastomotic leakage management.

Anatomy of mediastinal veins and nerves.

The mediastinum is the central compartment in the thoracic cavity that lies between the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly and sternum anteriorly to the vertebral column posteriorly. It is commonly divided into four compartments-superior, anterior, middle and posterior mediastinum. However, some have started to classify it into the more recent three compartments-anterior (prevascular), middle (visceral) and posterior (paravertebral). The mediastinum is of clinical significance because many vital structures, such as the heart, great vessels, esophagus, lymphatics, and trachea, lie within these compartments. Disease presentation can greatly vary depending on the structures involved, and the differential diagnosis can range widely. Therefore, knowledge of the anatomy and subdivisions of the mediastinum is vital for thoracic surgeons. Herein, we have provided a brief review of the mediastinal anatomy. Utilizing the four-compartment model, we detail the contents of each compartment of the mediastinum with special attention to its veins and nerves. There are also several venous junctions that are important for mediastinal surgery, such as the internal jugular-subclavian venous junction and the left-right brachiocephalic venous junction. We describe useful superficial landmarks, such as the sternocleidomastoid and manubrium, and how they relate to some of the key venous junctions.

An evaluation of cisplatin, doxorubicin, and cyclophosphamide (PAC) compared to other regimens for patients with unresectable or metastatic thymic carcinoma: A single-institution retrospective analysis.

e20650 Background: Thymic Epithelial Tumors (TETs) are uncommon tumors of the anterior mediastinum comprised of thymomas and Thymic Carcinomas (TC). Given the rarity of these tumors, little data exists regarding the comparative effectiveness of various combination therapies. Platinum-based treatment regimens in combination with anthracyclines (e.g., PAC), taxanes (e.g., carboplatin plus paclitaxel (CT)) or etoposide (PE) have demonstrated efficacy in TETs in the front-line setting (although current NCCN guidelines recommend only CT for the treatment previously untreated advanced TC). We sought to characterize the efficacy of these regimens for TCs in a real-world setting. Methods: We conducted a single-institution, retrospective database analysis of 164 TC patients seen at the IUSCCC from 1996 - 2020. Of those patients, 42 met the study criteria as having a de novo diagnosis of TC treated with front-line systemic chemotherapy and available outcome data. Chemotherapeutic intervention and demographic/clinical variables were evaluated in this study. Data was compiled and collected using descriptive statistics and the Kaplan Meier method for survival analysis via GraphPad Prism software. Results: Of the 42 patients identified to have sufficient data, the median age was 55.6 years (range, 21 - 82). The median follow-up for patients was 23 months. Metastatic sites of disease included the pleura (11%), lymph nodes (11%), bone (10%) and lungs (5%). Multi-site involvement accounted for 36% of cases. Squamous cell carcinoma (SCC) was found in 52.3% (n = 22) of the patients, while 26.2% (n = 11) had rare TC subtypes, including, SCC with basaloid features, SCC with neuroendocrine features, and neuroendocrine (21.4% of cases were classified as TC only). Most patients received first line treatment with PAC (n = 16), CT (n = 13) or PE (n = 9). There was no difference in progression free survival (PFS) for TC patients treated with PAC or CT (10.5 v. 7.5 months, respectively, NS). PE was associated with inferior outcomes compared to PAC (4.5 vs. 10.5 months, ***p = 0.0005) and CT (4.5 vs. 7.5 months, *p = 0.0158), respectively. A subgroup analysis of rarer histologic subtypes revealed a trend towards improved PFS for patients who received PAC compared to CT (9.5 v. 4.5 months, NS). Conclusions: The results of our study support PAC combination chemotherapy as a reasonable alternative for patients with previously untreated advanced TC. Further studies to correlate the genomic differences of common and uncommon TC subtypes will be crucial to optimize the role of conventional and targeted systemic therapies in this rare malignancy.

A Cervical Thymic Cyst in an Adult Female; A Case Report and Comprehensive Literature Review.

Introduction: Cervical thymic cyst accounts for (0.3-1) % of cervical cysts in children and are usually present during the first decade of life with few reported cases in adults. Herein, we present a 34-year-old female with a cervical thymic cyst. We conducted a review of all the previously reported cases as well. Case presentation: The patient complained of an anterolateral neck swelling that was noticed one year ago. It was a soft, fluctuant, mobile, non-tender swelling in the midline and the right side of the lower neck. Neck ultrasonography revealed a large thin-walled cyst, with no internal septa, echoes, or solid parts. Post-contrast MRI of the neck showed a well-defined, oblong-shaped, lobulated cystic lesion just beneath the strap muscle. The cyst extended caudally to the superior border of the anterior mediastinum at the level of the upper border of the manubrium sterni. The patient underwent excision of the swelling under general anesthesia via Kocher's collar neck incision. Connection with the thymus gland was detected behind the manubrium sterni which was separated. Pathological examination showed prominent thymic tissue confirming the diagnosis of a cervical thymic cyst. Conclusion: Adult cervical thymic cyst is very rare with a few cases reported in the literature. Surgical excision in symptomatic patients is the treatment of choice. Paper's main novel aspects: • A rare presentation of a cervical thymic cyst in an adult. • A comprehensive literature review including all the previously reported cases in one table.

Risk reduction of CNS relapse in diffuse large B cell lymphoma with intrathecal methotrexate prophylaxis: A single institution retrospective study.

e19531 Background: Central nervous system (CNS) relapse is an infrequent but serious and challenging complication in diffuse large B-cell lymphoma (DLBCL) that carries a dismal prognosis. While several risk factors have been identified to stratify the risk for CNS relapse including the 2015 CNS internal Prognostic index (CNS-IPI), controversy still remains regarding the indication, timing, and method of CNS prophylaxis. The purpose of this study was to determine whether IT-MTX reduced the risk of CNS relapse, as well as treatment related and financial toxicity of CNS prophylaxis. Methods: We performed a single-center, retrospective analysis on a cohort of 192 patients with DLBCL who had received treatment between January 2010- August 2022. Patients were identified by using ICD10 code diagnosis in the electronic medical records system. We included patients of all stages of disease and CNS-IPI scores along with patients with testis, breast, sinus, and bone marrow extranodal involvement. Patients with primary CNS disease and primary mediastinal disease were excluded from the study. Clinical data collected by chart review included age at time of diagnosis, sex, performance status, LDH level, disease stage, number and type of therapies administered including IT-MTX, extranodal involvement, MYC/BCL2/BCL6 translocation status, HIV status, cell of origin (COO), treatment response. Toxicities and complications thought to be associated with IT-MTX prophylaxis were also documented in addition to total costs of treatment for each patient. Patient characteristics were compared using Fisher exact test or Pearson’s chi-square test. Results: In patients with intermediate to high CNS relapse risk (CNS-IPI 2-5) IT-MTX did not reduce the 1 year risk of CNS relapse (RR 1.1296, 95% CI 0.1933 to 6.6012, P = 0.08924). The median time to CNS relapse was longer in patients who had received IT-MTX (13.5 months) vs those who did not (7 months). Thirty eight (52.8%) patients reported adverse side effects of any kind as a result of IT-MTX administration, with 23.6% of patients developing grade 2-3 adverse events. The average cost for CNS-prophylaxis was estimated to be approximately $8,059.04 over a patient’s treatment course, but as high as $20,140. Conclusions: In conclusion, our study highlights the necessity to develop improved standardized guidelines for use of CNS prophylaxis in patients with DLBCL. The results from our retrospective study add to the growing body of literature showing IT-MTX has limited and potentially transient effectiveness in preventing CNS relapse. Given the high rate of side effects and significant cost of IT-MTX, we recommend that clinicians carefully consider the risks and benefits of prophylaxis before prescribing IT-MTX for CNS-prophylaxis.

Pediatric gray zone lymphoma according to the 2022 WHO classification: An Italian cohort study.

The 2022 World Health Organization (WHO) classification redefines the concept of gray zone lymphoma (GZL), restricting it in practice to cases of mediastinal/thymic origin (mediastinal gray zone lymphoma, MGZL) with overlapping features between primary mediastinal B-cell lymphoma (PMBCL) and classical Hodgkin lymphoma (CHL). Cases with histological characteristics of GZL but occurring without mediastinal involvement are better classified as diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS), with few exceptions. We collected clinical and pathological data about all Italian pediatric patients diagnosed with GZL over a 20-year period. We identified only four cases of bona fide MGZL. All patients were adolescent and presented with a mediastinal disease, always associated with other nodal involvement. B symptoms and increased levels of both erythrocyte sedimentation rate (ESR) and lactate dehydrogenase (LDH) were observed. Only two patients achieved a first complete remission, suggesting a more aggressive clinical behavior than either PMBCL or CHL. Prospective studies evaluating prognostic factors and establishing the most effective first-line therapy for MGZL are highly needed.

Mediastinal Paraganglioma: A retrospective analysis of 51 cases

BackgroundParagangliomas are rarely found in the mediastinum, where they account for a small proportion of mediastinal masses. This study aimed to better characterize the presenting features and relevant aspects in optimizing the diagnosis and treatment of mediastinal paragangliomas. MethodsA computer-assisted search of electronic health records was performed to identify adult patients (≥18 years) who underwent evaluation for a primary mediastinal paraganglioma at Mayo Clinic between January 2000 and April 2022. Medical charts, laboratory tests and radiology images were reviewed to collect data. ResultsThe study included 51 patients, each with a single mediastinal paraganglioma. The median age was 47 years (IQR: 39–67), 67% females. Symptoms of catecholamine excess were manifest in 39% of patients, and 14% presented with mass effect, while the remaining 47% had no paraganglioma-related symptoms. Genetic testing was performed in 35 patients; 66% harbored a pathogenic variant in the succinate dehydrogenase enzyme complex. Most paragangliomas (71%) were in the middle mediastinum and showed uptake of intravenous contrast on chest imaging. Biopsies were performed in 30 (59%) patients; 27% were inconclusive and 10% resulted in major complications. Surgical resection occurred in 75%, primarily for relief of symptoms (50%) followed by proximity to critical structures (45%). Perioperative complications were common (66%), but there were no cases of local tumor recurrence during the follow-up period (median 8 years; IQR: 4–13). ConclusionMediastinal paragangliomas are most located in the middle mediastinum and can often be diagnosed noninvasively using a combination of clinical, biochemical, and radiological features.

Differentiation between rebound thymic hyperplasia and thymic relapse after chemotherapy in pediatric Hodgkin lymphoma.

Rebound thymic hyperplasia (RTH) is a common phenomenon caused by stress factors such as chemotherapy (CTX) or radiotherapy, with an incidence between 44% and 67.7% in pediatric lymphoma. Misinterpretation of RTH and thymic lymphoma relapse (LR) may lead to unnecessary diagnostic procedures including invasive biopsies or treatment intensification. The aim of this study was to identify parameters that differentiate between RTH and thymic LR in the anterior mediastinum. After completion of CTX, we analyzed computed tomographies (CTs) and magnetic resonance images (MRIs) of 291 patients with classical Hodgkin lymphoma (CHL) and adequate imaging available from the European Network for Pediatric Hodgkin lymphoma C1 trial. In all patients with biopsy-proven LR, an additional fluorodeoxyglucose (FDG)-positron emission tomography (PET)-CT was assessed. Structure and morphologic configuration in addition to calcifications and presence of multiple masses in the thymic region and signs of extrathymic LR were evaluated. After CTX, a significant volume increase of new or growing masses in the thymic space occurred in 133 of 291 patients. Without biopsy, only 98 patients could be identified as RTH or LR. No single finding related to thymic regrowth allowed differentiation between RTH and LR. However, the vast majority of cases with thymic LR presented with additional increasing tumor masses (33/34). All RTH patients (64/64) presented with isolated thymic growth. Isolated thymic LR is very uncommon. CHL relapse should be suspected when increasing tumor masses are present in distant sites outside of the thymic area. Conversely, if regrowth of lymphoma in other sites can be excluded, isolated thymic mass after CTX likely represents RTH.

Retrospective analysis of mediastinal tumors in childhood

Background: The aim of this study was to determine etiologic distribution, epidemiologic properties, treatment, clinical course and late effects of the treatment of the patients diagnosed with mediastinal tumor. Methods: Patients under 18 years old diagnosed with mediastinal tumors between January 1990 and June 2011 at the 19 Mayis university department of child oncology were examined retrospectively. Results: There were 50 (61%) males, 32 (39%) females with mediastinal tumor. Median age at diagnosis was 9.28 years (30 days-17.4 years). Most common symptoms were respiratory distress (29.2%) and cough (23.1%). Sixty eight cases (82.9%) were malignant. Two cases died before diagnosis. Thirty seven cases (45.1%) were located in anterior followed by 16 (19.5%) in middle and 23 (28%) in posterior mediastinum. Most common malignant tumors were lymphomas (n=46, 67.6%), followed by sarcomas (n=12, 17.6%), neural crest tumors (n=8, 11.8%) and germ cell tumors (n=2, 2.9%). Thirteen cases had vena cava superior syndrome and 4 cases had signs of spinal cord compression at the time of diagnosis. Forty eight cases (58.5%) were alive and symptom free on follow-up (mean 39.5 months, 3-139 months), and 22 (26.8%) were died. Sixteen cases (23.5%) had late effects. Overall survival for all malignant tumors were 60.5±7.8%. Conclusions: Mediastinal tumors should be considered in children with acute progressive respiratory distress and cough. Early diagnosis is still most important factor for prognosis.

UPLC-HRMS-based Plasma Metabolomics Study of Thymoma and Thymic Hyperplasia.

Thymoma is a rare malignant tumor but it is the most common primary tumor of the anterior mediastinum. The current imaging methods for thymoma screening suffer from false positive rate problem, and thymoma pathogenesis remains elusive. Study of thymoma metabolic characteristics could provide clues for improving the diagnosis and understanding the pathogenesis of thymoma. Metabolic profiling of sera from thymoma and thymic hyperplasia patients was performed using UPLC-HRMS in both positive and negative ionization modes. After pre- and post-processing, the dataset was divided into three age groups and statistical analysis was performed to select differential metabolites of thymoma. For feature identification, experimental MS/MS spectra were matched to those of databases and available chemical standards, and also manually annotated with plausible chemical structures to ensure high identification confidence. A total of 47 differential metabolites were identified in thymoma. Significant higher levels of histidine, sphinganine 1-phosphate, lactic acid dimer, phenylacetylglutamine, LPC (18:3) and LPC (16:1), and significant lower levels of phenylalanine, indole-3-propionic acid (IPA), hippuric acid and mesobilirubinogen were associated with thymoma. Tryptophan level in thymoma-associated myasthenia gravis (TAMG) was significantly lower than that of the MG (-) group. IPA and hippuric acid abundances exhibited increasing trends from indolent to aggressive thymoma. Our study revealed aberrant aromatic amino acid metabolism and fatty acid oxidation might be associated with thymoma. The identified unique metabolic characteristics of thymoma may provide valuable information for study of the molecular mechanism of thymoma pathogenesis, and improvement of diagnosis and discovery of new therapeutic strategies for thymoma.