• Korean Journal of Radiology
• /
• v.24 no.1
• /
• pp.62-78
• /
• 2023

As the majority of incidentally detected lesions in the anterior mediastinum is small nodules with soft tissue appearance, the differential diagnosis has typically included thymic neoplasm and prevascular lymph node, with benign cyst. Overestimation or misinterpretation of these lesions can lead to unnecessary surgery for ultimately benign conditions. Diagnosing mediastinal cysts using MRI serves as a problem-solving modality in distinguishing between surgical and nonsurgical anterior mediastinal lesions. The pitfalls of MRI evaluation for anterior mediastinal cystic lesions are as follows: first, we acknowledge the limitation of T2-weighted images for evaluating benign cystic lesions. Due to variable contents within benign cystic lesions, such as hemorrhage, T2 signal intensity may be variable. Second, owing to extensive necrosis and cystic changes, the T2 shine-through effect may be seen on diffusion-weighted images (DWI), and small solid portions might be missed on enhanced images. Therefore, both enhancement and DWI with apparent diffusion coefficient values should be considered. An algorithm will be suggested for the diagnostic evaluation of anterior mediastinal cystic lesions, and finally, a management strategy based on MRI features will be suggested.

• Korean Journal of Radiology
• /
• v.22 no.1
• /
• pp.139-154
• /
• 2021

Magnetic resonance imaging (MRI) has become a crucial tool for evaluating mediastinal masses considering that several lesions that appear indeterminate on computed tomography and radiography can be differentiated on MRI. Using a three-compartment model to localize the mass and employing a basic knowledge of MRI, radiologists can easily diagnose mediastinal masses. Here, we review the use of MRI in evaluating mediastinal masses and present the images of various mediastinal masses categorized using the International Thymic Malignancy Interest Group's three-compartment classification system. These masses include thymic hyperplasia, thymic cyst, pericardial cyst, thymoma, mediastinal hemangioma, lymphoma, mature teratoma, bronchogenic cyst, esophageal duplication cyst, mediastinal thyroid carcinoma originating from ectopic thyroid tissue, mediastinal liposarcoma, mediastinal pancreatic pseudocyst, neurogenic tumor, meningocele, and plasmacytoma.

• Journal of Chest Surgery
• /
• v.36 no.12
• /
• pp.985-990
• /
• 2003

Bilateral diaphragmatic paralysis is a rare disease. It is caused by trauma, cardiothoracic surgery, neuromuscular disorders, corvical spondylosis, and infection. A 60 year-old male patient developed bilateral diaphragmatic paralysis after an on-bloc resection of thymic carcinoma which invaded the right upper lobe, pericardium, superior vena cava and innominate vein. Severe respiratory difficulty developed and ventilator weaning was impossible. We performed bilateral diaphragmatic plication. After the operation, satisfactorily ventilator weaning and sleeping in supine position were possible; therefore, we report this case.

• Journal of Chest Surgery
• /
• v.37 no.8
• /
• pp.684-690
• /
• 2004

Background: Primary thymic epithelial neoplasm is a type of mediastinal tumors that have various biologic and morphologic features. In this study, we reclassified 59 cases of thymic epithelial tumors by the new WHO classification. We inquired whether the new WHO classification has independent prognostic relevance by analyzing clinical characteristics of thymic epithelial tumors including Masaoka's clinical stage. Material and Method: From December 1986 to August 2003, 59. patients who underwent surgery in the Keimyung University Dongsan Medical Center with definite diagnosis of thymic epithelial tumor were studied. We analyzed the histologic subtype (WHO classification). clinical stage (Masaoka's clinical stage) and patient's characteristics (sex, age, myasthenia gravis, tumor size, invasion. recurrence, metastasis) as prognostic factors. We analyzed the relationship between histologic subtype and clinical stage. Result: 32 patients were male and 27 were female. Mean age was 50.1$\pm$14.2. From WHO A to C, all thymic epithelial tumors were reclassified by the new WHO classification. Six patients (10.2%) had Type A, 7 (11.9%) had Type AB, 7 (11.9%) had Type B$_1$, 10 (16.9%) had Type B$_2$ and 7 (11.9%) had Type B$_3$, 22 (37.3%) had Type C. Two factors were shown by multivariate analysis to be associated with a favorable prognosis: completeness of resection (p=0.003) and non-invasiveness (p=0.001). The overall 5-year survival of the 59 patients was 53%, subtype A and AB were 92.3%, B$_1$ and B$_2$ were 70.2%, and B$_3$ and C were 26.1%. The association between histologic subtype and invasive behavior (stage) was statistically significant (p<0.001). Conclusion: The WHO classfication is not only a histologic classfication of the thymic epithelial tumors but also a significant prognostic factor that influence the survival of thymic epithelial tumors.

• Korean Journal of Bronchoesophagology
• /
• v.13 no.2
• /
• pp.34-39
• /
• 2007

Background: The mediastinum is the anatomic space which is restricted and the clinical aspect varies according to location, size and type of neoplasm. Diagnostic and therapeutic approaches to mediastinal neoplasms have changed over and over. We presented our recent therapeutic experiences with these neoplasms. The object and method: The 36 patients were treated in operation from 2000 until 2006. The male patients were 20 and the female patients were 16. Age of the patients ranged from 5 to 70, and the median age was $46.4{\pm}21.9$. The child patients were two. Result: The most prevalent anatomic distribution of the neoplasm was anterosuperior mediastinum. The most common neoplasm was thymoma, followed by thymic cyst, teratoma, ganglioneuroma. The complete excison of neoplasm was accomplished in 96% of patient group except thymoma patient group. One patient underwent total thymectomy, and the other 12 patients underwent extended thymectomy from 13 thymoma patient group. In the malignant neoplasm, 7 patients were received additional treatment after operation. There was short-term death of 1 person and late death of 1 person. Conclusion: Our results except clinical manifestation are compared favorably with other reports. Surgery is the management of choice for patients with mediastinal neoplasm and early curative resection is considered to optimize clinical outcome for patients.

• Advances in pediatric surgery
• /
• v.10 no.1
• /
• pp.39-42
• /
• 2004

Thymolipoma is a rare benign mediastinal tumor, composed of mature fatty and thymic tissues. A 9-year-old boy was referred with a one-month history of neck swelling. Preoperative computed tomography scan and fine needle aspiration biopsy suggested thymolipoma. Despite it being rare, thymolipoma should be considered in the differential diagnosis of mediastinal tumors. Characteristics of its clinical feature and radiological findings that can differentiated it from other mediastinal tumors are discussed with a review of the literatures.

• Journal of Chest Surgery
• /
• v.32 no.8
• /
• pp.726-731
• /
• 1999

Background: The distinction between non-invasive and invasive or thymic carcinoma has been severely compromised by lack of objective morphological criteria. A reliable biological marker of tumor aggressiveness is, therefore, mandatory for predicting tumor behavior. Material and Method: Thirty thymic epithelial tumors, including 7 non-invasive thymoma, 10 invasive thymoma, and 13 thymic carcinoma of the Rosai's classification; and 5 stage I, 7 stage II, 2 stage III, and 3 stage IVa of the Masaoka stage of thymoma were investigated for expression of bcl-2 and p53 proteins by immunohistochemistry. Result: The thymic epithelial cells showed positive immunostain for bcl-2 in 0 (0%), 3 (30%), 8 (61.5%) of categories in the Rosai's classification respectively and in 0 (0%), 1 (14.3%), 2 (100%), 0 (0%) of stage I, II, III, IVa of the Masaoka stage respectively. Thymic carcinoma, and high stage thymoma had significantly higher proportion of bcl-2 expression than thymoma (p=0.021) and low stage thymoma (p=0.011). However, p53 showed no correlation with the histological subtypes nor with clinical aggressiveness. Bcl-2 expression appeared to be positively correlated with p53 immunoactivity (p=0.007, kappa=0.525). Conclusion: These date indicate that bcl-2 expression correlates with aggressiveness in thymic epithelial tumors, but further studies on mutation of p53 protein is necessary because bcl-2 expression appeared to be positively correlated with p53 immunoactivity.

• Journal of Gastric Cancer
• /
• v.14 no.3
• /
• pp.207-210
• /
• 2014

The peritoneum is the most frequent site of recurrence for gastric cancer after gastrectomy, followed by the liver and lymph nodes. In contrast, metastasis to the thymus is rare. Annual surveillance with computed tomography was performed on a 67-year-old man who previously underwent a distal gastrectomy and D2 lymph node dissection for gastric cancer at Tottori University. Five years after the initial operation, an anterior mediastinal tumor was detected by computed tomography. The patient underwent video-assisted thoracic surgery to remove the tumor. Histopathology revealed adenocarcinoma cells similar to those of the gastric cancer resected 5 years previously. Thymic metastasis was considered likely based on the location of the tumor. The recognition that gastric cancer can metastasize to unusual anatomic locations, such as the thymus, can facilitate an accurate, prompt diagnosis and appropriate treatment.

• Journal of Chest Surgery
• /
• v.30 no.11
• /
• pp.1149-1153
• /
• 1997

Unilateral reexpansion pulmonary edema(RPE) is generally considered a rare complication occurring when a chronically atelectatic lung is rapidly reexpanded by tube thoracostomy or thoracentesis. It can also take place when the lung collapse is of short duration or when the lung is reexpanded without intrapleural sucti n. We experienced a case of RPE following surgical resection in mediastinal thymic cyst A 26 year old female patient suffered from long-standing atelectasis of the right lung due to a huge mediastinal cyst that was misrecognized as tuberculous pleural effusion. Empyema developed after iatrogenic rupture of mediastinal cyst by pig-tailed tube thoracostomy. We successfally managed the ruptured mediastinal thymic cyst, empyema and postoperatively developed RPE following reexpansion of the collapsed lung. The patient was treated with drugs and mechanical ventilation with positive end-expiratory pressure for RPE. The remainder of her hospital course was uneventful.

• Journal of Chest Surgery
• /
• v.38 no.8 s.253
• /
• pp.564-569
• /
• 2005

Background: Thymic carcinoma is a rare malignant disease with sparse data for treatment and prognosis. We intended to investigate the prognostic factors of thymic carcinoma. Material and Method: Data of 42 patients, who were diagnosed and treated for thymic carcinoma from January of 1986 to August of 2003 were reviewed retrospectively. Influences of characteristics of patients, Masaoka stage, histologic grade, completeness of resection and adjuvant treatment on survival were evaluated. Result: There were 30 male and 12 female patients and their mean age was $52.0\pm15.7$ years old. There were 28 patients with low-grade histology and 13 patients with high-grade histology. Clinical stage according to Masaoka stage were I in 2, II in 2, III in 15 $(35.7\%)$, IVa in 10 $(23.8\%),\;and\;IVb\;in\;13\;(31\%)$ patients. Surgical resection was done in 22 patients, Complete resection was possible in 13 patients and incomplete resection was done in 9 patients. Among 20 patients without resection, 8 patients received chemotherapy, 7 patients received radiotherapy and 5 patients received combined therapy. Median survival time was $31.7\pm6.1$ months and 5 year survival rate was $28.5\%$. High grade histology (hazard ratio=3.009, $95\%\;confidence\;interval=1.178\sim7.685,$ p=0.021) and incompleteness of resection (hazard ratio=3.605, $95\%$ confidence interval= $1.1541\sim1.580$, p=0.023) were the prognostic factors of thymic carcinoma. Conclusion: In thymic carcinoma, low grade histology is a good prognostic factor and complete resection can prolong the survival of patients.