Thymic Disorders Program

About the Program

The Thymic Disorders Program in the Massachusetts General Hospital Division of Thoracic Surgery has extensive expertise in treating the full spectrum of thymic conditions—from the most common to rare and complex thymic disorders.

Mass General has been a longstanding leader in the field of thymoma surgery. Our experience gives us a distinct advantage in understanding this rare condition and how best to treat it based on the patient's circumstances.

As part of our standard of care, we follow patients over the long term to monitor for possible recurrence. Where appropriate, we collaborate with thoracic oncology specialists from the Mass General Cancer Center, including medical oncologists and radiation oncologists, to treat patients with thymoma or thymic carcinoma. Our multidisciplinary approach to care enhances our ability to evaluate and treat our patients.

A History of Innovation

Mass General has been treating and researching thymic disorders since the 1950s. Today, members of our division are recognized nationally and internationally as experts on thymoma and other thymic disorders. We have published many significant papers on thymoma.

Conditions We Treat

Our surgeons are highly experienced in treating the following thymic conditions:

• Thymoma: The most common type of tumor found in the front of the mediastinum. We recommend the surgical removal of both benign and malignant thymomas
• Myasthenia gravis (MG): A rare autoimmune neuromuscular disorder that causes muscle weakness and is always diagnosed and medically stabilized by a neurologist. It is often associated with a thymoma, in which case the thymus and thymoma are removed. Many patients with MG are referred by their neurologist for a thymectomy to increase the chance of obtaining a remission of their MG and reducing the need for immunosuppressive medication
• Thymic hyperplasia: A benign condition in which the thymus is enlarged for unknown reasons. This usually does not require surgery. Instead, we follow the patient with magnetic resonance imaging (MRI) over time to confirm the condition is indeed benign
• Thymic carcinoma: A rare thymic tumor that when localized, is typically treated with chemotherapy or chemoradiotherapy, followed by surgery. If it is widespread, we treat it with chemotherapy

Our program also treats extremely rare conditions involving thymic cysts, thymolipoma and thymic carcinoids.

Patient Experience

What to Expect: Myasthenia Gravis

Patients with myasthenia gravis (MG) initially have their condition diagnosed and medically stabilized by a neurologist, who then refers the patient to our surgeons. The surgeon first arranges for the patient to have a computed tomography (CT) scan to look for a potential thymoma as MG has about a 25 percent chance of being associated with a thymoma. Based on the findings of this test and other factors, we work with the patient to determine the most appropriate surgical course of treatment.

Our division's physicians are highly skilled in performing transcervical thymectomy and video-assisted thoracoscopy (VATS), two minimally invasive procedures for thymus removal. We also perform standard open (i.e. transsternal) procedures. Recently, robotic-assisted minimally invasive thymectomy has been introduced as an additional option for selected patients. We have an excellent track record with all techniques in terms of patient outcomes.

Following surgery, the patient’s neurologist will provide ongoing follow-up, which may include medication management for any muscle weakness.

What to Expect: Thymoma

Our surgeons typically can diagnose thymoma by reading a CT scan. A PET/CT scan or MRI may also be necessary. Smaller tumors often are excised via surgery alone, which is a quick and effective approach.

Thymomas that are large and/or locally advanced require more complex treatment. We may begin by performing a fine-needle aspiration (FNA) biopsy, in which we sample cells from the tumor using a very thin needle.

Depending on the biopsy results, the patient may undergo chemotherapy or chemoradiotherapy and then surgery—all of which we coordinate with our thoracic oncology specialists at the Mass General Cancer Center. We usually perform open transsternal procedures in these cases, as we believe they produce better outcomes than minimally invasive approaches

What to Expect: Thymic Carcinoma

Thymic carcinomas are similar in nature to thymomas, but more advanced. These usually require chemotherapy or chemoradiotherapy before surgery.

Chance of recovery and treatment options for thymoma and thymic carcinoma depend on:

• Stage of cancer
• The patient's general health
• Type of cancer cell
• Whether the cancer has just been diagnosed or has come back
• Whether the tumor can be removed completely by surgery

Publications

Publications from physicians in the Thymic Disorders Program include:

• Results of a multi-institutional Phase II trial reporting successful use of neoadjuvant chemoradiotherapy prior to surgical resection, J Thorac Cardiovasc Surg, 2014
• Review of the surgical management of pleural recurrence of thymoma, Thorac Surg Clin, 2011
• Importance of World Health Organization (WHO) histology in thymoma management, Crit Rev Oncol Hematol, 2008
• Importance of size in determining the role of induction therapy, J Thorac Cardiovasc Surg, 2005
• Chemoradiotherapy as an option for induction treatment of locally advanced thymomas, Ann Thorac Surg, 2008
• The use of pleuropneumonectomy in patients with advanced (stage IVA) thymoma, Ann Thorac Surg, 2006
• Refining the need for adjuvant radiation in completely resected stage II thymoma, Ann Thorac Surg, 2002