• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5581-5585
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• 2012

Objective: To explore the relationship between computed tomography (CT) manifestations of thymoma and its WHO pathological classification. Methods: One hundred and five histopathologically confirmed cases were collected for their pathological and CT characteristics and results were statistically compared between different pathological types of thymoma. Results: Tumor size, shape, necrosis or cystic change, capsule integrity, invasion to the adjacent tissue, lymphadenopathy, and the presence of pleural effusion were significantly different between different pathological types of thymomas (P<0.05). Type B2, B3 tumors and thymic carcinomas were greater in size than other types. More than 50% of type B3 tumors and thymic carcinomas had a tumor size greater than 10 cm. The shape of types A, AB, and B1 tumors were mostly round or oval, whereas 75% of type B3 tumors and 85% of thymic carcinomas were irregular in shape. Necrosis or cystic change occurred in 67% of type B3 thymomas and 57% of thymic carcinomas, respectively. The respective figures for capsule destruction were 83% and 100%. Increases in the degree of malignancy were associated with increases in the incidence of surrounding tissue invasion: 33%, 75%, and 81% in type B2, type B3, and thymic carcinomas, respectively. Pleural effusion occurred in 48% of thymic carcinomas, while calcification was observed mostly in type B thymomas. Conclusions: Different pathological types of thymic epithelial tumors have different CT manifestations. Distinctive CT features of thymomas may reflect their pathological types.

• Journal of Chest Surgery
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• v.16 no.4
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• pp.571-583
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• 1983

Thymic tumor is the most common neoplasm originating in the anterior mediastinum. Histologically, thymic tumors and tumorlike conditions have been classified into thymic cyst, thymolipoma, true thymic hyperplasia, thymoma and carcinoid tumor of the thymus gland. We have experienced several tumors and a few tumorlike conditions of the thymus gland in 10 patients: thymoma 6, thymic hyperplasia 2, carcinoid tumor 1 and thymic cyst 1. The age distributions were ranging from 30 to 60 years except for one 3 year old child [malignant thymoma, lymphocytic type], and male to female ratio was 1:1.5. In 6 cases, thymic lesions were removed through lateral thoracic incision [right 2, left 4] because the mediastinal masses were growing far into the pleural space, meanwhile, medially located lesions [4 cases] through median sternotomy incision. Among these 10 patients, 3 were malignant thymomas, in which 2 were died of recurrence after tumor resection. Myasthenia gravis was all noted in 3 females [thymoma 2, thymic follicular hyperplasia 1], in which only two revealed remission in symptoms following thymectomy. The authors would like to recommend early radical thymectomy through median sternotomy incision whenever patients demonstrate suspicious thymic tumor lesions on the chest roentgenogram or generalized myasthenic symptoms.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2745-2748
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• 2012

Aims: To study KIT (CD117) expression in thymic epithelial tumors in China, and investigate diagnostic and clinical significance. Material and Methods: Thymic epithelial tumors (TETs) from 102 patients (3 type A, 29 type AB, 5 type B1, 22 type B2, 29 typeB3 and 16 thymic carcinomas) were examined. Immunohistochemical staining with an antic-kit monoclonal antibody was performed on a tissue microarray. Relationships between KIT positive expression and the TET clinical characteristics (WHO histologic classification and Masaoka stage system) were analysed. Results: The KIT positive expression rate was significantly higher in thymic carcinoma (60%, 9/16) than in thymoma (8%, 7/86), a strong correlation being found with the WHO classification, but not the Masaoka tumor stage. The overall survival for patients with KIT positive lesions was significantly worse. Conclusions: KIT is a good molecule marker to differentially diagnose thymic carcinoma from thymoma, while also serving as a predictor of prognosis for TETs. Further research into KIT mutations in Chinese TETs should be conducted to assess the efficacy of targeted therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.771-774
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• 2016

Thymic tumors are the most common tumors in the anterior mediastinum. Total resection is the main treatment and predictor of longer survival. Adjuvant radiotherapy alone or in combination with chemotherapy is recommended with incomplete excision or advanced disease. Thirty seven patients with thymic tumors were included in this retrospective study from January 2001 till December 2012. They were studied regarding age, sex, performance status, tumor size and invasion, stage, pathology, treatment given, overall and progression free survival. Myasthenia gravis was present in 18.1% of the patients. Masaoka stage III was diagnosed in 40.5% of the cases followed by stage II in 24.3% and the other stages with lower percentages. Pathology type B3 was the most frequent followed by B2 and B1 with percentages of 27, 24.3 and 21.7 respectively. Complete resection was conducted in 11 cases (29.75%). Partial resection or debulking was done in 15 (40.5%) and a biopsy was taken in 11 cases (29.8%) Adjuvant chemotherapy was given to 14 patients (37.8%) and neoadjuvant to 13 (35.2%). Adjuvant radiotherapy was given to 17 patients (46%) and neoadjuvant to 14 (37.8%). The 5-year overall survival by was 83% for stage I, 71% for stage II, 60% for stage III, and 44% for stage IV (p=0.0426). Five year progression free survival was 71% for stage I, 62% stage II, 42% stage III, and 37% for stage IV (p=0.0532). In conclusion with the rare thymic tumors early stage and complete resection have the highest impact on overall and progression free survival.

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

• Journal of Chest Surgery
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• v.25 no.11
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• pp.1236-1239
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• 1992

Carcinoid tumors arising in the thymus are rare. Since Rosai and Higa in 1972 distinguished these neoplasms from thymomas, fewer than 100 cases have been reported in the world literature. The pathologic diagnosis of thymic carcinoids is been on findings from light microscopy, histochemical studies, and electron microscopy. About 50% of thymic carcinoids are seen with endocrinopathies. Recurrence and extrathoracic metastasis are characteristic of thymic carcinoids. Surgical extirpation of the tumor initially and of the subseguent recurrences in the most effective treatment today The role of adjuvant radiotherapy and chemotherapy is still uncertain. Herein we report a case of thymic carcinoid tumor in a 36-year old male with brief review of literatures.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.718-722
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• 1999

Thymoma is the most common tumor in the compartment of anterior mediastinum. The malignant thymoma is classified into invasive thymoma(category I) and thymic carcinoma(category II). Recently, well-differentiated thymic carcinoma is a proposed category 1.5 used to describe a subset of thymic epithelial tumors, allowing for the existence of intermediate form based on the clinical features and the histological characteristics. Thymic cyst is a congenital or a acquired disorder. Congenital thymic cyst may develop due to failure of the thymopharyngeal duct to obliterate and acquired thymic cyst develops from inflammation(multilocular thymic cyst), or neoplasm(cystic thymoma). Cystic degeneration in thymoma is a relatively frequent but focal event. In rare cases, the process proceeds to the extent that most or all of the lesion becomes cystic. Until now, well-differentiated thymic carcinoma with extensive cystic degeneration has not been reported in our country. We experienced a case of 14 year-old female patient showing extensive cystic degeneration in well-differentiated thymic carcinoma. And so we report it with review of the articles related.

• Korean Journal of Bronchoesophagology
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• v.10 no.2
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• pp.68-71
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• 2004

Thymic cysts are uncommon tumors which usually occur in the neck and mediastinum. It is known to arise from embryonic remnants of the thymopharyngeal duct or from inflammation of thymic tissues. Patients with thymic cyst are often asymptomatic and identified after surgical removal and histologic examination. We experienced a 73 year-old man with recently developed dyspnea. During the examination, chest CT showed a $5\times6cm$ sized cystic mass causing deviation of the trachea. It was located in between the right thyroid gland and anterior mediastinum. It also caused tracheal narrowing noted by bronchoscopy. Right anterior cervical incision and removal of the mass was performed and a histological diagnosis of thymic cyst was confirmed. The patient was discharged without complication.

• Korean Journal of Bronchoesophagology
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• v.11 no.1
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• pp.25-27
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• 2005

Thymic cysts are uncommon tumors which usually occur in the neck and mediastinum. It is known to arise from embryonic remnants of the thymopharyngeal duct or from infammation of thymic tissues. Patients with thymic cyst are often asymptomatic and identified after surgical removal and histologic examination. We experienced a 73 year-old man with recently developed dyspnea. During the examination, chest CT showed a $5{\times}6cm$ sized cystic mass causing deviation of the trachea. It was located in between the right thyroid gland and anterior mediastinum. It also caused tracheal narrowing noted by bronchoscopy. Right anterior cervical incision and removal of the mass was performed and a histological diagnosis of thymic cyst was confirmed. The patient was discharged without complication.

• Tuberculosis and Respiratory Diseases
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• v.65 no.1
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• pp.23-28
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• 2008

Background: Thymic epithelial tumors are the most common tumors affecting the anterior mediastinum. The aim of this study is to investigate clinical features of the patients who were diagnosed with thymic epithelial tumors at Pusan National University Hospital. Methods: We retrospectively reviewed the records of thirty-seven patients who were diagnosed with thymic epithelial tumors from Jan. 1997 to Jan. 2007. The pathological classification and clinical stage of the thymic epithelial tumors were based on the WHO classification and Masaoka's staging system. A total 37 patients were enrolled: 23 were males and 14 were females, and their mean age was 51.3 years. Results: Thirty patients presented symptoms at the time of diagnosis and their symptoms were as follows: chest pain (53%), dyspnea (23%), and cough (17%). Myasthenia gravis was diagnosed in five patients. With respect to the tumor staging, three cases (8%) were stage I, 10 cases (28%) were stage II, 12 cases (32%) were stage III, 6 cases (16%) were stage IVA and 6 cases (16%) were stage IVB. Twenty-four cases (67%) displayed stage III or IV disease. The pathological types according to the WHO classification were as follows: B1 (32%), C (23%), B3 (20%), B2 (16%), AB (6%) and A (3%). Twenty-four patients underwent thymothymectomy and four of these patients relapsed. Stage III or type B3 was common in the relapsed patients. Five patientsexpired. Stage IV or type B3 and C were common in the expired patients. Conclusion: In this study, stage III or IV disease and type B3 or C were common at the time of diagnosis and these findings might contribute to postoperative recurrence and a poor outcome.