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.

Clinicopathological characteristics of unicentric Castleman disease: A single-center experience of 12 patients.

BACKGROUND: Castleman disease (CD) is an uncommon lymphoproliferative disorder with distinct pathological characteristics. Unicentric Castleman disease (UCD) presents as a single lymph node enlargement, often without significant symptoms. Complete surgical resection is the standard treatment for UCD. This study aimed to explore the clinicopathological features of UCD in a Taiwanese population. METHODS: We retrospectively identified 12 patients with UCD who had undergone surgical treatment between January 1, 2006 and June 30, 2022 at the National Taiwan University Hospital. Clinical and radiological findings were retrieved from medical records. All available pathological slides were reviewed. RESULTS: The patients' mean age was 38.1 years (range, 17 to 69); five (41.7%) were male, and seven (58.3%) were female. Nearly all cases of UCD were in the mediastinum, except for one case in the neck. Most patients were asymptomatic and without abnormal laboratory test results. Computed tomography revealed well-defined tumor borders, contrast enhancement, and occasional calcification. Ten patients underwent en bloc tumor resection, while the remaining two underwent partial resection. Among them, seven (58.3%) underwent video-assisted thoracoscopic surgery (VATS), and four (33.3%) underwent thoracotomy. The mean follow-up duration was 92 months. The patients who underwent total resection had no recurrence. CONCLUSION: Detailed clinicopathological information on UCD in the Taiwanese population is present in our article. Both complete and partial surgery are effective for treatment. VATS may be preferred over thoracotomy due to less operative time and bleeding.

Using CT to evaluate mediastinal great vein invasion by thymic epithelial tumors: measurement of the interface between the tumor and neighboring structures.

OBJECTIVES: For thymic epithelial tumors, simple contact with adjacent structures does not necessarily mean invasion. The purpose of our study was to develop a simple noninvasive technique for evaluating organ invasion using routine pretreatment computed tomography (CT). METHODS: This retrospective study analyzed the pathological reports on 95 mediastinal resections performed between January 2003 and June 2020. Using CT images, the length of the interface between the primary tumor and neighboring structures (arch distance; Adist) and maximum tumor diameter (Dmax) was measured, after which Adist/Dmax (A/D) ratios were calculated. Receiver operating characteristic (ROC) curves were used to analyze the Adist and A/D ratios. RESULTS: An Adist cut-off of 37.5 mm best distinguished between invaded and non-invaded mediastinal great veins based on ROC curves. When Adist > 37.5 mm was used for diagnosis of invasion of the brachiocephalic vein (BCV) or superior vena cava (SVC), the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the ROC curve for diagnosis of invasion were 61.9%, 92.5%, 81.25%, 82.2%, 81.97%, and 0.76429, respectively. Moreover, there were significant differences between BCV/SVC Adist > 37.5 mm and ≤ 37.5 mm for 10-year relapse-free survival and 10-year overall survival (p < 0.01). CONCLUSIONS: When diagnosing invasion of the mediastinal great veins based on Adist > 37.5 mm, we achieved a higher performance level than the conventional criteria such as irregular interface with an absence of the fat layer. Measurement of Adist is a simple noninvasive technique for evaluating invasion using CT. Key Points • Simple contact between the primary tumor and adjacent structures on CT does not indicate direct invasion. • Using CT images, the length of the interface between the primary tumor and neighboring structures (arch distance; Adist) is a simple noninvasive technique for evaluating invasion. • Adist > 37.5 mm can be a supportive tool to identify invaded mediastinal great veins and surgical indications for T3 and T4 invasion by thymic epithelial tumors.

Simultaneous resection of coexisting pulmonary and mediastinal lesions by video-assisted thoracic surgery: a case-series study.

BACKGROUND: With the growing number of patients with coexisting pulmonary and mediastinal lesions detected, reports about simultaneous video-assisted thoracic surgery (VATS) for these concurrent diseases are still rare. To further explore the safety and effectiveness of simultaneous resection of pulmonary and mediastinal lesions by uniportal or biportal VATS, we retrospectively analyzed the clinical data of the largest series of cases to date. METHODS: From July 2018 to July 2021, all patients whose pulmonary lesions and mediastinal tumors were resected simultaneously in our institution were retrospectively reviewed. Their demographic and clinical data were collected and analyzed. RESULTS: A total of 54 patients were enrolled, of whom 44 underwent unilateral uniportal VATS, 3 underwent bilateral uniportal VATS and 7 underwent unilateral biportal VATS. Seven cases were converted to thoracotomy during surgery. For the remaining 47 patients with various demographic and clinical characteristics, most of the operations were completed within 3 h (n = 33, 70.2%) with blood loss of no more than 100 mL (n = 43, 91.5%). The duration of chest tube drainage was 5.66 ± 3.34 days, and the average daily volume was 196.90 ± 122.31 mL. Four cases of postoperative complications occurred during hospitalization. The length of postoperative hospital stay was 8.60 ± 3.63 days. No severe complications or deaths were observed during follow-up. CONCLUSIONS: Uniportal and biportal VATS are safe and effective for simultaneous resection of selected coexisting pulmonary and mediastinal lesions, but the indications and operational details need more evaluation.

Computed tomography (CT)-derived radiomic features differentiate prevascular mediastinum masses as thymic neoplasms versus lymphomas.

OBJECTIVES: We aimed to assess the ability of radiomics, applied to not-enhanced computed tomography (CT), to differentiate mediastinal masses as thymic neoplasms vs lymphomas. METHODS: The present study was an observational retrospective trial. Inclusion criteria were pathology-proven thymic neoplasia or lymphoma with mediastinal localization, availability of CT. Exclusion criteria were age < 16 years and mediastinal lymphoma lesion < 4 cm. We selected 108 patients (M:F = 47:61, median age 48 years, range 17-79) and divided them into a training and a validation group. Radiomic features were used as predictors in linear discriminant analysis. We built different radiomic models considering segmentation software and resampling setting. Clinical variables were used as predictors to build a clinical model. Scoring metrics included sensitivity, specificity, accuracy and area under the curve (AUC). Wilcoxon paired test was used to compare the AUCs. RESULTS: Fifty-five patients were affected by thymic neoplasia and 53 by lymphoma. In the validation analysis, the best radiomics model sensitivity, specificity, accuracy and AUC resulted 76.2 ± 7.0, 77.8 ± 5.5, 76.9 ± 6.0 and 0.84 ± 0.06, respectively. In the validation analysis of the clinical model, the same metrics resulted 95.2 ± 7.0, 88.9 ± 8.9, 92.3 ± 8.5 and 0.98 ± 0.07, respectively. The AUCs of the best radiomic and the clinical model not differed. CONCLUSIONS: We developed and validated a CT-based radiomic model able to differentiate mediastinal masses on non-contrast-enhanced images, as thymic neoplasms or lymphoma. The proposed method was not affected by image postprocessing. Therefore, the present image-derived method has the potential to noninvasively support diagnosis in patients with prevascular mediastinal masses with major impact on management of asymptomatic cases.

[Mediastinal T lymphoblastic lymphoma/leukemia: clinicopathological and prognostic analyses of 61 cases].

Objective: To investigate the clinicopathologic features and prognosis of mediastinal T lymphoblastic lymphoma/leukemia (T-LBL/ALL). Methods: Sixty-one patients with mediastinal T-LBL/ALL diagnosed at First Affiliated Hospital of Zhengzhou University from August 1, 2011 to December 31, 2018 were enrolled. Their clinical, pathological, imaging features and prognosis were retrospectively analyzed. Results: Of the 61 patients with mediastinal T-LBL/ALL, 46 were male and 15 were female, with a male to female ratio of approximately 3∶1, aged 5 to 71 years (median 24 years, average of 24.5 years). Radiological findings were mediastinal soft tissue masses (58 cases) or mediastinal multiple enlarged lymph nodes (1 case). The tumor had a diameter of 4.9 to 18.3 cm in size, and data of 2 cases was unavailable. The patient's main symptoms were superior vena cava syndrome (cough, dyspnea, facial or neck edema), shortness of breath and chest pain, while about 1/3 of patients developed B symptoms (high fever, night sweats or significant weight loss). All 61 cases were biopsy specimens, and 2 of the tumors were later resected. Histopathologic examination showed that the thymic tissue epithelial network structure was destroyed or completely disappeared. A large number of lymphocytoid tumor cells were diffusely infiltrative, with infiltration into adipose tissue, starry sky phenomenon, linear-like arrangement, interstitial collagen hyperplasia and tumor cell extrusion. Focal tumor necrosis was present in some cases. Tumor cells were overall small to medium in size. They had little cytoplasm, slightly distorted, round or oval-shaped nuclei, fine chromatin, and innocuous/small nucleoli. Immunohistochemical studies showed that the tumor cells expressed CD7 (100%, 33/33), TDT (93.4%, 57/61), CD99 (83.3%, 25/30), CD1a (4/7), CD10 (8/18), CD34 (13.2%, 5/38), but did not express B cell markers (CD20 and PAX5) or granulocyte monocyte marker (MPO). The Ki-67 proliferation index was usually greater than 50%. One case was tested for TCR clonal rearrangement, which was positive. Several hemotherapy regiments were used. Hyper-CVAD (cyclophosphamide, vindesine, dexamethasone, and epirubicin) were most frequently administrated (60.4%, 32/53), followed by BFM-90 (50.9%, 27/53). Some patients were treated with the above two and other treatment options. Follow-up data were available in 55 of the 61 patients, and 26 patients (47.3%) survived. The average five-year survival rate was 50.6%. The patient's prognosis was not significantly related to the International Prognostic Index, age of onset, gender, or tumor size. Conclusions: The mediastinal T-LBL/ALL is rare, and most of its specimens are needle biopsies. The histological morphology is often difficult to interpret, while the addition of clinical features and immunohistochemistry may help. The combination of CKpan, TDT, CD99, CD7, CD3, PAX5, CD34, CD10, and Ki-67 immunohistochemicl studies may assist in diagnosis of the most cases.

A rare presentation of cephalad extension of an anterior mediastinal teratoma - A case report.

We report a case of a 28 year old female who presented to us in November 2016 with a swelling in front of neck for three years and worsening shortness of breath for last one year, causing right sided tracheal deviation and mildSuperior Vena Caval obstruction. X-ray showed a soft tissue density mass in antero-superior mediastinum with cephalad extension. Contrast enhanced CT neck and chest revealed a multi cystic lesion extending from the root of neck to anterior mediastinum causing compression and deviation of trachea, and nearby structures especially Superior Vena Cava (SVC) along with collateral formation. Mass was surgically excised from the neck and mediastinum with uneventful post-operative recovery. Histopathology was consistent with benign mature cystic teratoma.

Extragonadal germ cell tumor of the posterior mediastinum in a child complicated with spinal cord compression: a case report.

BACKGROUND: Germ cell tumors (GCTs) in children are rare neoplasms with diverse pathological findings according to the site and age of presentation. The most common symptoms in children with mediastinal GCTs, which are nonspecific, are dyspnea, chest pain, cough, hemoptysis, vena cava occlusion syndrome, and fatigue/weakness. Because of these nonspecific symptoms, it is difficult to suspect a mediastinal mass. A posterior mediastinal tumor causing spinal cord compression is an important example of an oncologic emergency arising from a neurogenic tumor. CASE PRESENTATION: Children with posterior mediastinum GCTs can be easily mistaken as having a neurogenic tumor because of site of tumor origin. We treated our 7-year-old patient with emergency decompression surgery and high-dose steroid pulse therapy to prevent secondary injury to the spinal cord. Primary injury was a result of spinal cord compression due to the initial manifestation of GCT in the posterior mediastinum. Cisplatin-based chemotherapy was also administered. The patient was followed up regularly for 3 years and is undergoing rehabilitation without any signs of recurrence. CONCLUSIONS: We present an extremely rare case of a child with paraparesis caused by extradural spinal cord compression as the initial manifestation of GCT in the posterior mediastinum. The child was treated with emergency decompression surgery and high-dose pulse steroid therapy to prevent secondary injury to the spinal cord.

[Primary mediastinal large B-cell lymphoma: a clinicopathologic study of 27 cases].

Objective: To study the clinicopathologic characteristics and diagnostic criteria of primary mediastinal B-cell lymphoma (PMBL), and to distinguish PMBL from classic Hodgkin lymphoma(CHL) and systemic diffuse large B-cell lymphoma(DLBCL). Methods: The clinical features, histologic findings, results of immunohistochemical study and prgnosis in 27 PMBL cases were analyzed, with review of literature. Results: The age of patients ranged from 19 to 82 years (median age 34 years). All cases were located in the mediastinum and frequently accompanied by superior vein cava syndrome. Histologically, the tumor cells were pleomorphic and diffusely distributed. Clear cytoplasm and spindle tumor cells were seen in some cases. Varying amount of sclerosing stroma with collagen deposition was seen.Immunohistochemical study showed that the tumor cells were positive for CD20(100%, 27/27), CD30 (64.0%, 16/25), CD23 (77.3%, 17/22) and p63 (16/19). Clonal B cell gene rearrangement was seen. Conclusions: PMBL is a subtype of diffuse large B-cell lymphoma with various histomorphology. Immunohistochemistry can help to confirm the diagnosis, and the prognosis is better than diffuse large B cell lymphoma, not otherwise specified.

[Mediastinal germ cell tumors]. / Mediastinale Keimzelltumoren.

The mediastinum is among the most frequent anatomic region in which germ cell tumors (GCT) arise, second only to the gonads. Mediastinal GCT (mGCT) account for 16 % of all mediastinal neoplasms. Although the morphology and (according to all available data) the molecular genetics of mediastinal and gonadal GCT are identical, a number of unique aspects exist. There is a highly relevant bi-modal age distribution. In pre-pubertal children of both sexes, mGCT consist exclusively of teratomas and yolk sac tumors. The prognosis is generally favorable with modern treatment. In post-pubertal adults, virtually all patients with malignant mGCT are males; the prognosis is more guarded and depends (among other factors) on the histological GCT components and is similar to GCT in other organs. So-called somatic type malignancies (i. e. clonally related, non-germ cell neoplasias arising in a GCT) are much more frequent in mGCT than in other organs, and the association between mediastinal yolk sac tumors and hematological malignancies, such as myelodysplasias and leukemias, is unique to mediastinal tumors. The prognosis of GCT with somatic type malignancies is generally dismal.

Primary mediastinal B-cell lymphoma - metabolic and anatomical features in 18FDG-PET/CT and response to therapy.

AIM OF THE STUDY: Determining the role of PET/CT imaging in the evaluation of treatment efficacy in primary mediastinal B-cell lymphoma (PMBCL). MATERIAL AND METHODS: Retrospective analysis of seven PMBCL patients, treated at the University Hospital in Krakow, with interim PET/CT after the third course of chemo-immunotherapy.The analysis was based on the calculation of exact tumour volume and metabolic activity, compared with initial values (directly after diagnosis). RESULTS: Patients (five females, two males, average age 26.2 years, range 18-40 years), in clinical stage IIBX at diagnosis, were treated with eight cycles of R-CHOP-14 regimen, with radiotherapy consolidation (7/7) and central nervous system prophylaxis (6/7). The observed decrease in tumour volume between the initial staging and the interim PET ranged 72-89%. The mean ΔSUVmax reduction between initial (when available) and interim PET was 87% (range 84-89%). In 3/7 cases in the interim PET/CT, the uptake of the tumour was higher than the liver (Deauville Criteria score 4-5), and in 4/7 it was lower than the liver but higher than mediastinal blood pool structures (score 3 according to Deauville Criteria). After a median follow-up of 58 months - OS and EFS is 100%. CONCLUSIONS: The excellent clinical outcome in the study group corresponds with very good metabolic and volumetric response in the interim PET. The ΔSUVmax seems to be easier in implementation and has a more significant impact than other measurements.

Exuberant Vasculoconnective Component in Mediastinal Mixed Germ Cell Tumors.

We aimed to evaluate the histologic components of primary mediastinal mixed germ cell tumors. A total of 221 patients diagnosed with a mediastinal germ cell tumor (GCT) were retrospectively reviewed. Among them, 14 patients underwent surgical resection after chemotherapy and 8 patients were diagnosed with mixed GCT, who were then selected for further evaluation. Clinical chart review and histologic review of biopsy and surgical specimens of 8 patients were performed. All 8 patients were young males and showed a mature teratoma or a mature teratoma with a focal immature teratoma in the resected specimens. Serum alpha-feto protein was variably elevated. Seven patients experienced an increase in tumor size after the chemotherapy. In 5 patients, a variable amount of vasculoconnective tissue was found along with the mature teratoma occupying average 66.3% of resected mass, and 3 of them showed an identical vasculoconnective component on biopsy before chemotherapy. We suggest that vasculoconnective tissue might be the intrinsic component of primary mediastinal mixed GCT. When vasculoconnective tissue is obtained on small biopsy of an anterior mediastinal mass of a young male, the possibility of underlying mixed GCT should be considered and further clinical work up should be performed.

Prognostic significance of immunophenotypes and a nodular pattern in primary mediastinal large B-cell lymphoma.

To investigate the clinicopathological and prognostic significance of a nodular pattern and immunophenotypes in primary mediastinal large B-cell lymphoma (PMBL), histopathological features, including a nodular pattern and immunophenotypes, were analyzed in 58 Japanese PMBL patients. The patients were 23 men and 35 women with a median age of 31 years. The 4-year progression free survival (PFS) rate was 78%, and the 4-year overall survival (OS) rate was 89%. Among the histopathological and immunohistochemical features, Bcl6(+) (P = 0.013), MUM1(+) (P = 0.091), and pale cytoplasm (P = 0.064) were favorable prognostic indicators of PFS, and Bcl6(+) (P = 0.051) and MUM1(+) (P = 0.07) were favorable prognostic indicators of OS. Patients with Bcl2 negativity (n = 11) had 4-year PFS and OS rates of 100%. Histologically, a nodular pattern, resembling nodular sclerosis classical Hodgkin lymphoma (CHL), was observed in 22 patients (38%). However, this was not a significant prognostic indicator. In conclusion, Bcl6(+) , MUM1(+) , Bcl2(-) , and pale cytoplasm are candidate favorable prognostic indicators for PMBL and should be further examined in larger studies. We suggest that PMBL with a nodular pattern may belong to the same histological spectrum as nodular sclerosis CHL.

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.

Internal jugular vein-femoral vein diversion during anterior mediastinal mass resection and superior vena cava replacement.

Surgery which involves anterior mediastinal mass resection with artificial replacement of the superior vena cava results in significant disruption to the circulatory system. In this case, a pathway was established to divert blood from the internal jugular to the femoral vein after clamping of the superior vena cava. Blood which would ordinarily return to the right atrium via the superior vena cava was now being returned via the inferior vena cava. The mean arterial pressure was maintained at least 50 mmHg higher than the central venous pressure during clamping of the superior vena cava to avoid cerebral hypoperfusion. The combined use of the above strategies aimed to provide satisfactory surgical conditions and cerebral protection.

Development and Validation of a CT-Radiomics Nomogram for the Diagnosis of Small Prevascular Mediastinal Nodules: Reducing Nontherapeutic Surgeries.

RATIONALE AND OBJECTIVES: The preoperative diagnosis of small prevascular mediastinal nodules (SPMNs) presents a challenge, often leading to unnecessary surgical interventions. Our objective was to develop a nomogram based on preoperative CT-radiomics features, serving as a non-invasive diagnostic tool for SPMNs. MATERIALS AND METHODS: Patients with surgically resected SPMNs from two medical centers between January 2018 and December 2022 were retrospectively reviewed. Radiomics features were extracted and screened from preoperative CT images. Logistic regression was employed to establish clinical, radiomics, and hybrid models for differentiating thymic epithelial tumors (TETs) from cysts. The performance of these models was validated in both internal and external test sets by area under the receiver operating characteristic curve (AUC), while also comparing their diagnostic capability with human experts. RESULTS: The study enrolled a total of 363 patients (median age, 53 years [IQR:45-59 years]; 175 [48.2%] males) for model development and validation, including 136 TETs and 227 cysts. Lesions' enhancement status, shape, calcification, and rad-score were identified as independent factors for distinction. The hybrid model demonstrated superior diagnostic performance compared to other models and human experts, with an AUC of 0.95 (95% CI:0.92-0.98), 0.94 (95% CI:0.89-0.99), and 0.93 (95% CI:0.83-1.00) in the training set, internal test set, and external test set respectively. The calibration curve of the model demonstrated excellent fit, while decision curve analysis underscored its clinical value. CONCLUSION: The radiomics-based nomogram effectively discriminates between the most prevalent types of SPMNs, namely TETs and cysts, thus presenting a promising tool for treatment guidance.

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.

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.