Magnetic Resonance Elastography of Anterior Mediastinal Tumors.

BACKGROUND: Preoperative differentiation of the types of mediastinal tumors is essential. Magnetic resonance (MR) elastography potentially provides a noninvasive method to assess the classification of mediastinal tumor subtypes. PURPOSE: To evaluate the use of MR elastography in anterior mediastinal masses and to characterize the mechanical properties of tumors of different subtypes. STUDY TYPE: Prospective. SUBJECTS: 189 patients with anterior mediastinal tumors (AMTs) confirmed by histopathology (62 thymomas, 53 thymic carcinomas, 57 lymphomas, and 17 germ cell tumors). FIELD STRENGTH/SEQUENCE: A gradient echo-based 2D MR elastography sequence and a diffusion-weighted imaging (DWI) sequence at 3.0 T. ASSESSMENT: Stiffness and apparent diffusion coefficients (ADC) were measured in AMTs using MR elastography-derived elastograms and DWI-derived ADC maps, respectively. The aim of this study is to identify whether MR elastography can differentiate between the histological subtypes of ATMs. STATISTICAL TESTS: One-way analysis of variance (ANOVA), two-way ANOVA, Pearson's linear correlation coefficient (r), receiver operating characteristic (ROC) curve analysis; P < 0.05 was considered significant. RESULTS: Lymphomas had significantly lower stiffness than other AMTs (4.0 ± 0.63 kPa vs. 4.8 ± 1.39 kPa). The mean stiffness of thymic carcinomas was significantly higher than that of other AMTs (5.6 ± 1.41 kPa vs. 4.2 ± 0.94 kPa). Using a cutoff value of 5.0 kPa, ROC analysis showed that lymphomas could be differentiated from other AMTs with an accuracy of 59%, sensitivity of 97%, and specificity of 38%. Using a cutoff value of 5.1 kPa, thymic carcinomas could be differentiated from other AMTs with an accuracy of 84%, sensitivity of 67%, and specificity of 90%. However, there was an overlap in the stiffness values of individual thymomas (4.2 ± 0.71; 3.9-4.5), thymic carcinomas (5.6 ± 1.41; 5.0-6.1), lymphomas (4.0 ± 0.63; 3.8-4.2), and germ cell tumors (4.5 ± 1.79; 3.3-5.6). DATA CONCLUSION: MR elastography-derived stiffness may be used to evaluate AMTs of various histologies. TECHNICAL EFFICACY: Stage 2.

Robot-assisted thoracoscopic resection of a posterior mediastinal tumor with immunoglobulin G4-related disease: a case report.

BACKGROUND: Immunoglobulin (Ig)G4-related disease affects nearly every organ, and its clinical course varies depending on the involved organ; however, its occurrence in the mediastinum is rarely reported. CASE PRESENTATION: A 58-year-old woman presented with a posterior mediastinal tumor along the thoracic spine on imaging. Based on her elevated serum IgG4 level of 349.7 mg/dL, IgG4-related disease was suspected. Since the tumor was growing and malignancy could not be excluded, surgical resection was performed for definitive diagnosis. Robot-assisted thoracoscopic surgery was performed via the left semipronation and right thoracic approaches. The irregularly-shaped tumor was located on the level of the seventh to ninth thoracic vertebra, along the sympathetic nerve. A malignancy was not excluded based on the appearance of the tumor. The tumor had poor mobility. The sympathetic nerves, intercostal arteries, and veins were also excised. In this case, the articulated forceps, used during the robotic surgery, were useful in achieving complete tumor resection along the vertebral body. The pathological examination revealed IgG4-positive plasma infiltration, which fulfilled the criteria for IgG4-related diseases. The postoperative course was uneventful, and the patient underwent follow-up on an outpatient basis without additional medications. CONCLUSION: The clinical presentation of IgG4-related disease varies, based on the involved organs. This case was rare because the mediastinum was involved, and it emphasized the effectiveness of surgical resection.

Mediastinal malignant rhabdoid tumor in an infant: A rare case report.

Mediastinal malignant rhabdoid tumor (MRT) is an exceedingly rare and aggressive neoplasm, particularly uncommon in infants. We present the case of a previously healthy 7-month-old male infant with mediastinal MRT. The patient initially presented with left eyelid ptosis and was otherwise asymptomatic. Initial investigations, including brain MRI, yielded unremarkable results, and the infant was discharged with vitamin B supplements. However, he was readmitted a week later with prolonged fever, poor feeding, diarrhea, and respiratory distress. Despite an initial diagnosis of bronchiolitis/viral respiratory tract infection, the patient's condition rapidly deteriorated. Subsequent evaluation revealed mediastinal MRT as the underlying cause. This case underscores the diagnostic challenges associated with mediastinal MRT in infants and highlights the importance of considering rare neoplastic etiologies in atypical clinical presentations.

Spatiotemporal distribution of mediastinal neoplasms: A comprehensive multi-center study.

OBJECTIVES: Mediastinal neoplasms are typical but uncommon thoracic diseases with increasing incidence and unfavorable prognoses. A comprehensive understanding of their spatiotemporal distribution is essential for accurate diagnosis and timely treatment. However, previous studies are limited in scale and data coverage. Therefore, this study aims to elucidate the distribution of mediastinal lesions, offering valuable insights into this disease. MATERIALS AND METHODS: This multi-center, hospital-based observational study included 20 nationwide institutions. A retrospective search of electronic medical records from January 1st, 2009, to December 31st, 2020, was conducted, collecting sociodemographic data, computed tomography images, and pathologic diagnoses. Analysis focused on age, sex, time, location, and geographical region. Comparative assessments were made with global data from a multi-center database. RESULTS: Among 7,765 cases, thymomas (30.7%), benign mediastinal cysts (23.4%), and neurogenic tumors (10.0%) were predominant. Distribution varied across mediastinal compartments, with thymomas (39.6%), benign cysts (28.1%), and neurogenic tumors (51.9%) most prevalent in the prevascular, visceral, and paravertebral mediastinum, respectively. Age-specific variations were notable, with germ cell tumors prominent in patients under 18 and aged 18-29, while thymomas were more common in patients over 30. The composition of mediastinal lesions across different regions of China remained relatively consistent, but it differs from that of the global population. CONCLUSION: This study revealed significant heterogeneity in the spatiotemporal distribution of mediastinal neoplasms. These findings provide useful demographic data when considering the differential diagnosis of mediastinal lesions, and would be beneficial for tailoring disease prevention and control strategies.

Computed tomography-guided percutaneous needle biopsy for middle mediastinal tumors with retroaortic paravertebral approach: A case report.

A 74-year-old man was referred to our hospital for a close examination of a mediastinal mass. Contrast-enhanced CT showed a middle mediastinal tumor. We planned to perform a CT-guided percutaneous needle biopsy of the tumor using a retroaortic paravertebral approach to avoid transpulmonary puncture. A coaxial blunt-tip needle with a side hole was used to create space in the mediastinum and avoid azygos vein injury. After injecting normal saline, a blunt-tip needle was advanced through the space between the aorta and the vertebral body to the anterior surface of the tumor, and tissue was obtained. The patient was discharged the following day with no complications. For percutaneous middle mediastinal tumor biopsy, the retroaortic paravertebral approach may be a safe, effective route.

Management of a Large Hypervascular Apicoposterior Mediastinal Mass Using the Purse-String Suture Technique in Robotic-Assisted Thoracoscopic Surgery: A Case Report.

Complete resection of an apicoposterior mediastinal mass is essential due to the mass effect, which exerts pressure on adjacent organs. Recently, the use of minimally invasive surgery has had many advantages. In this report, we describe a case in which a large apicoposterior mediastinal hypervascular mass was managed using a purse-string suture technique during robotic-assisted thoracoscopic surgery (RATS). The patient, a 77-year-old woman, was diagnosed with a 6.2-cm apicoposterior mediastinal hypervascular solid mass originating from the branches of the right subclavian artery. The patient underwent RATS for treatment. To obtain an adequate view of the apex of the thoracic cavity, a needle aspiration was performed, followed by the application of a purse-string suture technique. This was done to reduce the size of the tumor and to prevent catastrophic events such as seeding or spillage of the cystic mass. The mass was histopathologically diagnosed as a schwannoma. The patient was discharged on the first postoperative day without experiencing any complications.

Tumor-to-thoracic height ratio as an easy method to predict the feasibility of reduced-port video-assisted thoracic surgery for mediastinal lesions in children: a single-center experience.

In the last few decades, reduced-port video-assisted thoracic surgery (RP-VATS) has been developed to minimize surgical invasiveness. Nevertheless, VATS in children can occasionally be difficult because the lesion occupies a small thoracic cavity, limiting the working space. This study aimed to assess the feasibility of RP-VATS for the resection of mediastinal lesions in children in association with the tumor-to-thoracic height ratio (TTH ratio). We reviewed all patients aged ≤10 years who underwent resection for mediastinal lesions in our institute between January 2008 and August 2022. Patients who underwent diagnostic procedures were excluded from this study. The TTH ratio was calculated as tumor height divided by thoracic height. Seven patients in the RP-VATS group and six in the conventional procedures (multi-portal VATS or open surgery) group were included in this study. The TTH ratio was significantly lower in the RP-VATS group than in the conventional procedures group (median, 26.3% vs. 50.8%; P=0.007). The operating time (P=0.01) and duration of drainage (P=0.003) were significantly shorter and the blood loss (P=0.001) was significantly lower in the RP-VATS group than in the conventional procedures group. After adjusting for age, a lower TTH ratio was significantly associated with the completion of RP-VATS (odds ratio: 0.776; 95% confidence interval: 0.529-0.926; P=0.048). In conclusion, RP-VATS can be performed appropriately in carefully selected cases of pediatric mediastinal lesions. A low TTH ratio may predict the feasibility of RP-VATS. Further studies are warranted to determine the criteria for the indications of RP-VATS in children, so that more children can benefit from RP-VATS.

A massive immature mediastinal teratoma treated with chemotherapy and surgical resection: a case report.

BACKGROUND: Teratoma is a type of germ cell tumor consisting of one or multiple tissues derived from germinal layers. The location and size of the tumor can cause various presentations. Here we report one of the largest ever cases of immature cystic teratoma. CASE PRESENTATION: In this report, we presented a 24-year-old patient with dyspnea, chest pain, nausea, and anorexia. A computed tomography scan revealed a giant, right-sided mass measuring about 190 × 150 × 140 mm. Chemotherapy was initiated for the patient, followed by thoracotomy. Histopathological evaluation revealed the nature of the mass to be an immature mediastinal teratoma. CONCLUSION: the incidence of immature mediastinal teratoma is uncommon, and due to its rarity, the diagnosis needs more profound evaluation studies such as radiological and pathological assessments. Immature teratomas are optimally treated by a combination of chemotherapy and complete resection.

Surgical removal of an unusual huge solitary fibrous tumor in the mediastinum: a case report.

BACKGROUND: Intrathoracic Solitary Fibrous Tumors (SFT) mainly arise from the pleura; however, these tumors may also originate from the mediastinum. We present a rare case of posterior SFT extending to several mediastinal sites and with an unusual large size, successfully treated with surgical resection. CASE PRESENTATION: A 66-year-old female presented with an initial manifestation of ambiguous pain in the chest and dysphagia and later developed pitting edema in both lower extremities and cachexia five months before admission. Chest imaging confirmed a mediastinal mass (17 × 15 × 8 cm) which was surgically removed. Immunohistochemistry confirmed the diagnosis of a solitary fibrous tumor with positive B-cell lymphoma 2, STAT6, and CD99, negative S100 and smooth muscle actin, and low levels of Ki67 (5-7%). The patient's follow-up course was unremarkable. CONCLUSION: Mediastinal SFTs may grow extremely huge, with the potential to invade multiple adjacent sites. Surgical removal of the tumor remains the mainstay of treatment in these cases.

Management of Parastomal Recurrence Following Total Laryngectomy.

Parastomal recurrence occurs in around 5% of patients undergoing total laryngectomy for laryngeal squamous cell carcinoma. It carries a poor prognosis which has changed little over the last 50 years, and poses a significant challenge to the head and neck surgeon. At present, surgical excision offers the only realistic chance of cure, although patients must be selected carefully following thorough work-up and in-depth multidisciplinary team discussion. This article provides a review of the literature on the management of parastomal recurrence following total laryngectomy.

A Rare Case of Mediastinal Mass: Thymoma and Thymic Tumor.

Thymomas and thymic carcinomas are rare mediastinal neoplasms arising from thymic epithelial cells, and the presence of synchronous or metachronous primary thymic neoplasms in a single patient is an extremely rare event. Thymoma patients appear to have an inherent predisposition toward developing additional neoplasms. This additionally presents a diagnostic challenge, revealing the importance of multidisciplinary expertise to the management of these patients. This is a case report of a patient with a thymoma and thymic carcinoma, submitted to surgical resection and postoperative radiotherapy.

Extracellular volume fraction derived from equilibrium contrast-enhanced CT as a diagnostic parameter in anterior mediastinal tumors.

PURPOSE: To assess the usefulness of extracellular volume (ECV) fraction derived from equilibrium contrast-enhanced CT (CECT) for diagnosing anterior mediastinal tumors. METHOD: This study included 161 histologically confirmed anterior mediastinal tumors (55 low-risk thymomas, 57 high-risk thymomas, 32 thymic carcinomas, and 17 malignant lymphomas) that were assessed by pretreatment CECT. ECV fraction was calculated using measurements obtained within the lesion and the aorta on unenhanced and equilibrium phase CECT. ECV fraction was compared among anterior mediastinal tumors using one-way ANOVA or t-test. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the ability of ECV fraction to differentiate thymic carcinomas/lymphomas from thymomas. RESULTS: ECV fraction differed significantly among the anterior mediastinal tumors (p < 0.001). ECV fraction of thymic carcinomas was significantly higher than those of low-risk thymomas, high-risk thymomas, and lymphomas (p < 0.001, p < 0.001, and p = 0.006, respectively). ECV fraction of lymphomas was significantly higher than that of low-risk thymomas (p < 0.001). ECV fraction was significantly higher in thymic carcinomas/lymphomas than in thymomas (40.1 % vs. 27.7 %, p < 0.001). The optimal cutoff value to differentiate thymic carcinomas/lymphomas from thymomas was 38.5 % (AUC, 0.805; 95 %CI, 0.736-0.863). CONCLUSIONS: ECV fraction derived from equilibrium CECT is helpful in diagnosing anterior mediastinal tumors. High ECV fraction is indicative of thymic carcinomas/lymphomas, particularly thymic carcinomas.

Aortic Wall Abrasion Caused by Needle Injury after Endoscopic Ultrasound-Guided Fine Needle Aspiration of a Mediastinal Hemangioma.

Benign mediastinal cysts are challenging to diagnose. Although Endoscopic Ultrasound (EUS) and EUS-guided fine needle aspiration (FNA) can accurately diagnose mediastinal foregut cysts, little is known about their complications. This paper reports a rare case in which EUS-FNA performed on mediastinal hemangioma resulted in an aortic hematoma. A 29-year-old female patient was commissioned for EUS of an asymptomatic accidental mediastinal lesion. Chest CT revealed a 4.9×2.9×10.1 cm thin-walled cystic mass in the posterior mediastinum. EUS revealed a large, anechoic cystic lesion with a regular thin wall with negative Doppler. EUS-guided FNA was performed using a single-use 19-gauge aspiration needle (EZ Shot 3; Olympus, Tokyo, Japan), and approximately 70 cc of serous pinkish fluid was aspirated. The patient was in a stable condition with no signs of acute complication. One day after EUS-FNA, thoracoscopic resection for mediastinal mass was conducted. The purple and multi-loculated large cyst was removed. Upon removal, however, an aortic hematoma caused by a focal descending aortic wall injury was observed. After a few days of close observation, the patient was discharged upon stable 3D aorta angio CT findings. This paper reports a rare and severe complication of EUS-FNA, in which an aspiration needle caused a direct injury to the aorta. The injection must be performed carefully to avoid damaging the adjacent organs or digestive tract walls.

Mediastinal Teratoma Mimicking Neurofibroma in CT-Guided Biopsy in a Patient With Neurofibromatosis Type 1.

Teratomas are a type of germ cell tumor that may contain several different types of tissue. Neurofibroma is a benign peripheral nerve sheath tumor with the plexiform type being pathognomonic for neurofibromatosis type 1. We report a case of a 33-year-old woman with a background of Neurofibromatosis type 1 who presented with left-sided chest pain and shortness of breath. She was diagnosed with a large mediastinal mass which was confirmed from a CT-guided biopsy as neurofibroma. Following a multidisciplinary team discussion, she underwent mediastinal mass resection and the final histopathology report revealed mediastinal mature teratoma.

[Classification of Hodgkin lymphoma and related entities : News and open questions]. / Klassifikation der Hodgkin-Lymphome und verwandter Entitäten : Neuigkeiten und offene Fragen.

Two new classifications were recently released: the 5th edition of the WHO classification of hematolymphoid tumors and the International Consensus Classification (ICC) drafted by the Clinical Advisory Committee. In the preparation of both classifications, the previously existing lymphoma categories were reevaluated according to recently obtained data on clinical, morphological, and molecular findings. In this review we summarize the current placements of classic and nodular lymphocyte predominant Hodgkin lymphoma and their relevant differential diagnoses.

Metastatic prostate cancer presenting as a posterior mediastinal mass: A rare presentation.

A 68-year-old African American male presented to the emergency department with back and abdominal pain. Imaging showed a posterior mediastinal mass interposed between the carina, the left main stem bronchus, and the descending thoracic aorta. Biopsy of the mass favored a metastatic prostate carcinoma, which is an extremely rare presentation.

[Lesions of the prevascular mediastinum]. / Läsionen des prävaskulären Mediastinums.

CLINICAL/METHODOLOGICAL ISSUE: Mediastinal masses are a group of heterogenous lesions which may be a coincidental finding or present with symptoms. More than half of mediastinal lesions are located in the prevascular mediastinum. As these tumors are not often encountered in clinical routine, making a diagnosis with a high degree of confidence may seem challenging. STANDARD RADIOLOGICAL METHODS: The latest computed tomography (CT)-based classification of the mediastinal compartments by the International Thymic Malignancy Interest Group (ITMIG) moves away from earlier radiograph-based classification systems and helps to reliably classify tumors based on location, although in some cases the lesion can occupy more than one compartment. PERFORMANCE: Radiology plays an important role in the evaluation of anterior mediastinal lesions. Although in some cases imaging features alone allow a diagnosis to be made; in other cases knowledge of important radiological features and their analysis in the context of patient factors like age and duration of symptoms can help to narrow down the differential diagnosis, avoid unnecessary workup, and guide further steps. PRACTICAL RECOMMENDATIONS: Computed tomography (CT) is central for the characterization of mediastinal masses in clinical routine. In some situations, like in the case of thymic cysts or thymic hyperplasia, magnetic resonance imaging (MRI) can be used as a noninvasive problem-solving tool.

Cavernous mediastinal hemangioma presenting with persistent cough: a rare case report and review of literature.

BACKGROUND: Cavernous hemangioma is a rare benign tumor which can sometimes mimic the clinical presentation and radiological findings of malignant tumors. Here we present a rare presentation of cavernous hemangioma in the mediastinum (CHM), along with a literature review among the main databases. CASE PRESENTATION: We present a 48-year-old male who had suffered from persistent cough as the sole symptom of an anterior CHM. Computed tomography scan demonstrated a 12.5 × 10.8 cm mass in the anterior mediastinum. The mass was surgically resected, and histopathological evaluation established the diagnosis of CHM. The patient was discharged in good condition, in which during his four-month follow-up period, no recurrence of the tumor has been observed. CONCLUSION: Although cavernous hemangioma rarely present in the mediastinum, it should be considered in the differential diagnosis of mediastinal tumors. However, our review of literature demonstrated a female dominance and average age of 40 years, with a 52% mortality rate based on previous reports.

Role of diffusion-weighted MRI in differentiation between benign and malignant anterior mediastinal masses.

Diffusion-weighted imaging (DWI) is considered to be a useful biomarker to characterize the cellularity of lesions, yet its application in the thorax to evaluate anterior mediastinal lesions has not been well investigated. The aims of our study were to describe the magnetic resonance (MR) characteristics of anterior mediastinal masses and to assess the role of apparent diffusion coefficient (ADC) value in distinguishing benign from malignant lesions of the anterior mediastinum. We conducted a retrospective cross-sectional study including 55 patients with anterior mediastinal masses who underwent preinterventional MR scanning with the following sequences: T1 VIBE DIXON pre and post-contrast, T2 HASTE, T2 TIRM, DWI-ADC map (b values of 0 and 2000 sec/mm2). The ADC measurements were obtained by two approaches: hot-spot ROI and whole-tumor histogram analysis. The lesions were grouped by three distinct ways: benign versus malignant, group A (benign lesions and type A, AB, B1 thymoma) versus group B (type B2, B3 thymoma and other malignant lesions), lymphoma versus other malignancies. The study was composed of 55 patients, with 5 benign lesions and 50 malignant lesions. The ADCmean, ADCmedian, ADC10, ADC90 in the histogram-based approach and the hot-spot-ROI-based mean ADC of the malignant lesions were significantly lower than those of benign lesions (P values< 0.05). The hot-spot-ROI-based mean ADC had the highest value in differentiation between benign and malignant mediastinal lesions, as well as between group A and group B; the ADC cutoffs (with sensitivity, specificity) to differentiate malignant from benign lesions and group A from group B were 1.17 x 10-3 mm2/sec (80%, 80%) and 0.99 x 10-3 mm2/sec (78.4%, 88.9%), respectively. The ADC values obtained by using the hot-spot-ROI-based and the histogram-based approaches are helpful in differentiating benign and malignant anterior mediastinal masses.