An Abnormal Chest x-Ray

Figure 1. Chest x-ray.

Figure 1. 

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Figure 2. Computed tomographic scan of the chest. Computed tomography revealed an anterior mediastinal mass separated from the lung. The patient underwent a neck exploration and the mass was found to be a thymoma. Mediastinal tumors or cysts are grouped according to their location in the anterior, middle, or posterior mediastinum.¹The anterior mediastinum is defined as the area posterior to the sternum and anterior to the heart and great vessels. The middle mediastinum contains the heart and the pericardium, while the posterior mediastinum is posterior to the heart and anterior to the upper thoracic vertebrae. The most common lesions of the anterior mediastinum are thymomas (47%), lymphomas (22%), endocrine tumors (16%), and germ cell tumors (16%).²Most patients with thymomas are asymptomatic on initial examination, although those with symptoms of chest pain, cough, or dyspnea are more likely to have a malignant type of thymoma.³There is no characteristic radiographic appearance of a thymoma on chest x-ray but the CT scan can provide evidence of invasion into adjacent structures. The diagnosis is made when the mass is excised, usually through a median sternotomy.⁴Thymomas are also associated with a wide variety of autoimmune abnormalities, such as myasthenia gravis, hypogammaglobulimenia, and pure red blood cell aplasia.⁵The staging for a thymoma is according to clinical, anatomic, and histologic characteristics.⁶

Figure 2. 

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Corresponding author and reprints: Syed Hashmi, MD, Division of Surgical Critical Care, Department of Surgery, Brigham and Women' s Hospital, 75 Francis St, Boston, MA 02115 (e-mail: shashmi@partners.org).