If you don't remember your password, you can reset it by entering your email address and clicking the Reset Password button. You will then receive an email that contains a secure link for resetting your password
If the address matches a valid account an email will be sent to __email__ with instructions for resetting your password
Abnormalities of the thymus comprise more than half of the lesions found in the anterior mediastinal compartment in adults. Greater than 95% of the tumors of the thymus are thymomas that originate from thymic epithelial cells. They generally present as an incidental radiographic finding. They are of surgical importance both as isolated entities as well as in association with myasthenia gravis (MG). Surgical excision is the cornerstone of therapy for thymoma.
He pulled the enlarged thymus out of the mediastinum and performed a pexy of the thymic capsule to the posterior aspect of the manubrium. Transcervical thymic surgery was generally the preferred route until the 1930s. In 1936, Dr. Alfred Blalock performed the first successful transsternal thymectomy through an upper median sternotomy in a patient with myasthenia gravis and a large anterior superior mediastinal tumor.
Radical transsternal resection evolved from this approach and the surgical technique now focuses on the en bloc resection of the entire thymus and pericardial fat pad from the thyroid gland down to the diaphragm and laterally to the phrenic nerves. This is performed through a full sternotomy. Advantages of this approach are direct and safe access to the entire anterior mediastinum. Opening the pleural spaces allows visualization and preservation of the phrenic nerves. Advocates of this approach feel that radical resection is the technique that is most likely to remove all thymic tissue and give the highest likelihood of cure, particularly in the setting of myasthenia gravis.
They point to the fact that even small portions of remnant thymic tissue has been associated with recurrent myasthenic symptoms and that reoperation after transcervical thymectomy has been required for resection of remnant tissue.
In children, thymic hyperplasia can be associated with a variety of endocrine disorders including hyperthyroidism. In adults, thymic hyperplasia has been associated with thymoma as well as many immune dysfunction syndromes—the most notable being myasthenia gravis. Removal of the thymus gland, by a variety of surgical approaches, appears to influence the immune dysfunction observed in myasthenia gravis.
The mechanism of this influence, and the relative benefit of removing all residual or ectopic thymic tissue, is unclear.
The most frequent asymptomatic indication for thymectomy is thymoma. Chest CT scan imaging of the thymus gland is often diagnostic of a thymic mass because the thymus gland is the only anatomic structure anterior to the brachiocephalic vein. Thymomas are not associated with lymphadenopathy. The presence of a separate aortopulmonary window mass or paratracheal adenopathy should raise the possibility of lymphoma. Similarly, Hodgkin’s disease can be associated with thymic enlargement.
In most cases, the radiographic appearance of thymoma is sufficient to preclude the necessity of a tissue biopsy before surgical resection. Further, tissue biopsy is notoriously inefficient because of the marked heterogeneity within the thymus gland. It is common for a resected thymoma to reflect areas of lymphocyte predominance (stage I) and epithelial predominance (stage III) within the same tumor.
Although the subsequent development of pleural implants is commonly attributable to presurgical biopsy, the supportive data are weak. Pleural implants clearly occur without prior biopsy. Similarly, needle or mediastinotomy biopsy is infrequently associated with localized pleural disease. Local incisional recurrence has rarely been reported.
Thymic carcinomas are rare epithelioid malignancies. Thymic carcinomas are frequently aggressive tumors that spread both within the pleural space (so-called “drop” metastases) as well as hematogenously. In most cases, the diagnosis is suspected on the radiographic studies and confirmed by anterior mediastinotomy. These tumors should be treated with aggressive combination therapy.
Combined neoadjuvant chemoradiation therapy followed by aggressive radical surgery has had only a limited impact on patient survival.
In the absence of lymphadenopathy, mediastinal invasion, or anatomic ambiguity, we recommend transsternal total thymectomy of a thymoma without prior biopsy. The transsternal approach can be performed with a cosmetically acceptable incision. The superficial skin incision of 7 to 8 cm is comparable to the aggregate incision of a thoracoscopic approach and the sternotomy is well tolerated by most patients. More importantly, the transsternal approach provides sufficient incision and exposure to extract the tumor intact for detailed pathologic evaluation of the thymic capsule and to adequately assess for any local invasion. We feel that this approach provides exposure of the neck and anterior mediastinum that is superior to a transcervical approach. We recommend transsternal thymectomy for thymomas that may require a radical resection and for total resection of the observable thymus gland and associated ectopic thymic tissue.