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Mayo Clinic Proceedings Nov 1993Thymomas and thymic carcinomas are thymic epithelial tumors that constitute approximately 15% of all mediastinal masses. From 28 to 66% of thymomas cause chest symptoms... (Review)
Review
Thymomas and thymic carcinomas are thymic epithelial tumors that constitute approximately 15% of all mediastinal masses. From 28 to 66% of thymomas cause chest symptoms as the initial manifestation; the rest are discovered on routine chest roentgenograms or during investigations prompted by the presence of a paraneoplastic syndrome. Forty percent of patients with thymoma have one or more paraneoplastic syndromes, including myasthenia gravis, pure red cell aplasia, and hypogammaglobulinemia. Extrathymic malignant lesions develop in up to 20% of patients. Traditional histologic classifications have not accurately predicted tumor behavior; a recently developed classification based on cellular differentiation toward thymic medullary or cortical epithelium may correlate better with prognosis. Nevertheless, the prognosis is best predicted by stage of the tumor determined intraoperatively and is poorer in patients with incomplete resection than in those with complete resection of the thymoma. In addition to surgical intervention, irradiation and chemotherapy have important roles in the management of thymomas, particularly in advanced stages. In this article, the clinical manifestations, diagnosis, pathologic features, staging, and treatment of thymomas are reviewed, and the prognosis of affected patients is discussed.
Topics: Humans; Neoplasm Staging; Paraneoplastic Syndromes; Prognosis; Thymoma; Thymus Gland; Thymus Neoplasms
PubMed: 8231276
DOI: 10.1016/s0025-6196(12)60907-0 -
Chinese Medical Journal 2013To review the presentation, diagnosis, staging and treatment of thymoma. (Review)
Review
OBJECTIVE
To review the presentation, diagnosis, staging and treatment of thymoma.
DATA SOURCES
Data were obtained from papers on thymoma published in English within the last 30 years. No formal systematic review was conducted, but an effort was made to be comprehensive.
STUDY SELECTION
Studies were selected if they contained data relevant to the topic addressed in the particular section. In particular, standards adopted by the International Thymic Malignancies Interest Group through a formal process of achieving worldwide consensus are featured. Because of the limited length of this article, we have frequently referenced recent reviews that contain a comprehensive amalgamation of literature rather than the actual source papers.
RESULTS
Thymomas are rare malignant tumors. They account for about half (47%) of anterior mediastinal tumors. About one third of these are associated with myasthenia gravis. Computed tomography with intravenous contrast is the standard diagnostic modality. Thymomas appear as round or oval masses in early stages but irregular shapes with calcifications occurring in later stages. They can invade surrounding structures including mediastinal fat, pleura, major blood vessels and nerves. Fine needle aspiration, core needle biopsy or open biopsy is used to obtain tissue diagnosis. Masaoka-Koga classification is currently used to stage thymomas. All thymomas should be considered for resection due to their malignant potential. A complete resection is a major prognostic factor and every effort should be made to achieve this even if this means resection and reconstruction of a major thoracic structure. Median sternotomy is the standard approach for thymoma resection. A number of minimally invasive techniques are used in selective centers. While stage I and II tumors undergo primary surgery, preoperative chemotherapy appears to increase the chances of complete resection for stage III and IVa tumors. Postoperative radiation could be considered for patients with residual disease. Excellent 5 and 10-year survival rates are noted for completely resected early stage thymomas.
CONCLUSIONS
Thymic malignancies are rare tumors. Standards have recently been achieved to allow better communication and promote collaborative research. Surgical resection is the mainstay of treatment, but a multimodality approach is useful for many patients.
Topics: Humans; Incidence; Neoplasm Recurrence, Local; Neoplasm Staging; Thymoma; Thymus Neoplasms; Tomography, X-Ray Computed
PubMed: 23769581
DOI: No ID Found -
Oncology (Williston Park, N.Y.) Oct 2012Thymomas are unusual tumors, representing no more than 1% of all malignancies. However, thymomas are the most common epithelial tumors of the anterior mediastinum....
Thymomas are unusual tumors, representing no more than 1% of all malignancies. However, thymomas are the most common epithelial tumors of the anterior mediastinum. Unfortunately, there is no general agreement regarding the best parameters to use to predict clinical behavior in these tumors.This review considers the status of the different histological classifications thus far presented for thymomas and offers an analysis of the association between histology and clinical behavior. It also emphasizes the importance of proper staging of thymomas, delineating the benefits and shortcomings of different proposed staging systems and offering thoughts on a better and more accurate staging stratification for patients with these tumors. All of the different parameters are presented in relation to survival rates. Based on current information, staging with proper stratification remains the most important parameter for predicting prognosis. For tumors limited to the mediastinal compartment, surgical resection is the most effective treatment, while induction therapy is a good alternative for patients in whom surgical resection is not possible.
Topics: Clinical Trials as Topic; Combined Modality Therapy; Humans; Neoplasm Staging; Prognosis; Thymoma; Thymus Neoplasms
PubMed: 23176011
DOI: No ID Found -
The Journal of Medical Investigation :... Feb 2008Thymoma is the most common tumor of the anterior mediastinum. This tumor is associated with unique paraneoplastic syndromes (myasthenia gravis, pure red cell aplasia,... (Review)
Review
Thymoma is the most common tumor of the anterior mediastinum. This tumor is associated with unique paraneoplastic syndromes (myasthenia gravis, pure red cell aplasia, hypogammaglobulinemia, and other autoimmune diseases). The rarity of this tumor has somewhat obscured the optimal treatment. Although the histologic classification of thymoma has remained a subject of controversy for many years, the WHO classification system, published in 1999, appeared to be an advance in our understanding of thymoma. The optimal treatment for thymoma depends on its clinical stage. Surgery remains the mainstay of treatment for thymic epithelial tumors. Thymomas also have a high response rate to chemotherapy or radiotherapy. Only surgical resection is performed for patients with stage I (non-invasive) thymoma. The value of postoperative radiotherapy in completely resected stage II or III tumors is questionable. Multimodality therapy involving surgery, chemotherapy and radiotherapy appears to increase the rate of complete resection and survival in advanced (stage III and IV) thymomas.
Topics: Antineoplastic Agents; Chemotherapy, Adjuvant; Cisplatin; Combined Modality Therapy; Humans; Neoplasm Staging; Prognosis; Radiotherapy Dosage; Radiotherapy, Adjuvant; Thymectomy; Thymoma; Thymus Neoplasms; World Health Organization
PubMed: 18319541
DOI: 10.2152/jmi.55.17 -
Ultrastructural Pathology 1991Thymoma is the most common tumor of the anterior-superior mediastinum, especially in middle-aged or older adults. Microscopically, thymomas can be differentiated from... (Review)
Review
Thymoma is the most common tumor of the anterior-superior mediastinum, especially in middle-aged or older adults. Microscopically, thymomas can be differentiated from other tumors with which they can be confused by the finding of a mixed population of cells, including neoplastic thymic epithelial cells with numerous processes surrounding activated-appearing lymphocytes. Thymomas can be classified as benign or malignant, and the majority of those that are malignant appear cytologically benign and are locally invasive. Cytologically benign thymomas have been classified as being lymphocyte rich, epithelial cell rich, or spindle cell type. This classification has not been found to be prognostically useful. A new method classifies these tumors as being cortical, medullary, or mixed. This new classification appears to have prognostic significance. Malignant thymomas that are cytologically malignant are uncommon. Such tumors usually are squamous cell carcinomas. Other types include sarcomatoid carcinoma, clear cell carcinoma, basaloid carcinoma, and mucoepidermoid carcinoma. Because other tumors can occur in the anterior mediastinum, electron microscopy and/or immunocytochemistry is helpful in making the distinction. The differential features by ultrastructural and immunocytochemical analysis are reviewed.
Topics: Humans; Microscopy, Electron; Thymoma; Thymus Neoplasms
PubMed: 1755103
DOI: 10.3109/01913129109016250 -
European Journal of Cardio-thoracic... 1994Three hundred ninety patients who underwent thymectomy for myasthenia gravis (MG) were followed up to investigate the development of associated malignancies. There were... (Comparative Study)
Comparative Study Review
Three hundred ninety patients who underwent thymectomy for myasthenia gravis (MG) were followed up to investigate the development of associated malignancies. There were 102 patients with thymoma and 288 without thymoma. Malignant neoplasms were detected in ten patients, four of whom already had the tumor at the time MG was diagnosed. Thus, malignancy developed after thymectomy in six patients. Malignant fibrous histiocytoma (MFH) developed in three patients, as well as gastric cancer, gastric leiomyosarcoma, rectal cancer, liver cancer, lung cancer, breast cancer, and thymic carcinoid in one patient each. Nine of the ten malignancies developed in the thymoma group, and only one in the non-thymoma group. The predicted number of patients with malignancy was 2.63 in the thymoma group and 2.65 in the non-thymoma group. Our findings suggest that the presence of thymoma facilitates the occurrence of extrathymic malignancy, and that thymectomy never enhances the occurrence of malignancy but possibly inhibits it.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myasthenia Gravis; Neoplasms, Second Primary; Thymectomy; Thymoma; Thymus Neoplasms; Time Factors
PubMed: 8043287
DOI: 10.1016/1010-7940(94)90155-4 -
Taiwan Yi Xue Hui Za Zhi. Journal of... Aug 1989Spontaneous pneumothorax is a rare complication in both primary and metastatic pulmonary neoplasms. Occasionally, pneumothorax is associated with chemotherapy of... (Review)
Review
Spontaneous pneumothorax is a rare complication in both primary and metastatic pulmonary neoplasms. Occasionally, pneumothorax is associated with chemotherapy of pulmonary malignancies. Pneumothorax after chemotherapy has been reported only in cases with osteogenic sarcoma, synovial sarcoma, fibrosarcoma, germinal tumors, and lymphoma with lung metastasis. We report a case of a patient with malignant thymoma who suffered from lung metastasis after radiation and adjuvant chemotherapy from lung metastasis after radiation and adjuvant chemotherapy (cyclophosphamide, adriamycin, and cis-platinum). A chest X-ray taken 2 days after chemotherapy showed bilateral pneumothorax, which was resolved with conservative treatment. The pneumothorax in this patient is believed to have been caused by the rupturing of the tumor into the pleural cavity and the bronchi.
Topics: Adult; Antineoplastic Agents; Humans; Liver Neoplasms; Male; Pneumothorax; Thymoma; Thymus Neoplasms
PubMed: 2687436
DOI: No ID Found -
Wiener Klinische Wochenschrift Sep 2005Thymoma is a rare epithelial tumor of the thymus, but the most common malignancy in the anterior mediastinum. A unique feature is its association with paraneoplastic... (Review)
Review
Thymoma is a rare epithelial tumor of the thymus, but the most common malignancy in the anterior mediastinum. A unique feature is its association with paraneoplastic syndromes, in particular myasthenia gravis. According to the WHO classification 6 histologic types of thymic epithelial tumors can be discriminated. Tumor stage according to MASAOKA is the most important prognostic factor. Non-invasive tumors (stage I) are usually completely resected and no further therapy is warranted. For incompletely resected tumors and locally advanced invasive thymomas (stage Ill-IV) postoperative radiotherapy with 50-60 Gy is advisable. Chemotherapy, preferably with Cisplatinum, is indicated with inoperable thymomas or metastatic disease. In general thymomas have a fair prognosis even in advanced stage. Long term follow-up is mandatory up to 10 years.
Topics: Drug Therapy; Humans; Neoplasm Recurrence, Local; Practice Guidelines as Topic; Practice Patterns, Physicians'; Prognosis; Radiotherapy; Thymoma; Thymus Neoplasms
PubMed: 16416343
DOI: 10.1007/s00508-005-0407-y -
Romanian Journal of Morphology and... 2010Thymomas are rare tumors of the thymic epithelium with a broad spectrum of morphological and clinical features. Despite a benign histological appearance, it can invade...
Thymomas are rare tumors of the thymic epithelium with a broad spectrum of morphological and clinical features. Despite a benign histological appearance, it can invade nearby structures or metastasize. The majority of patients are asymptomatic, but some may present with paraneoplastic syndromes such as myasthenia gravis, red cell aplasia, or hypogammaglobulinemia. Various staging systems of thymomas have been defined based on the degree of invasiveness. According to the WHO Classification, there are six histologic types of thymic epithelial tumors. The most important prognostic factor is the stage according to Masaoka's system. We report a case of invasive thymoma diagnosed incidentally in a patient with cardiovascular risk factors referred to the cardiologist with suspected thoracic aorta aneurism.
Topics: Humans; Lung; Middle Aged; Neoplasm Invasiveness; Thymoma; Thymus Neoplasms; Tomography, X-Ray Computed
PubMed: 20809041
DOI: No ID Found -
La Revue Du Praticien Apr 2017Thymic tumors. Thymic epithelial tumors are rare malignancies, that may be aggressive and difficult to treat, with variable prognosis. The histopathological...
Thymic tumors. Thymic epithelial tumors are rare malignancies, that may be aggressive and difficult to treat, with variable prognosis. The histopathological classification distinguishes two major tumor types: thymomas and thymic carcinomas. Autoimmune manifestations are observed in nearly one third of patients at diagnosis; myasthenia gravis is the most common, followed by pure red cell aplasia and hypogammaglobulinemia. Assessing the resectability of the tumor represents the first stage of the therapeutic strategy, as complete resection is the most significant prognostic factor on patient survival. For unresectable thymic tumors, treatment is then based on induction chemotherapy followed by surgical resection or radiotherapy. Following a call of the French National Cancer Institute, a network of expert centers for the management of thymic malignancies started in in 2012: RYTHMIC.
Topics: Humans; Myasthenia Gravis; Neoplasm Staging; Neoplasms, Glandular and Epithelial; Prognosis; Thymoma; Thymus Neoplasms
PubMed: 30512890
DOI: No ID Found