History and Physical Examination
Many mediastinal tumors and cysts produce no symptoms and are found incidentally during chest radiography or other imaging studies of the thorax performed for another reason. Symptoms are present in approximately one third of adult patients with a mediastinal tumor or cyst but are seen more commonly in the pediatric population, in which nearly two thirds present with some symptoms. In adults, asymptomatic masses are more likely to be benign.
Symptoms associated with the respiratory tract predominate in pediatric patients because airway compression is more likely, owing to the significant malleability of the airway structures and the small size of the chest cavity in infants and children. Symptoms most often observed include persistent cough, dyspnea, and stridor. If the location and size of the mass produces partial or complete obstruction, obstructive pneumonia can also occur. Infectious symptomatology, and even signs of sepsis, can occur if a mediastinal cyst becomes infected.
Constitutional symptoms, such as weight loss, fever, malaise, and vague chest pain, commonly occur with malignant tumors in pediatric patients.
Symptoms associated with compression of some portion of the respiratory tract can be produced by benign lesions in adults, but this occurs much less commonly than in children. Infectious symptoms or sepsis from infection of a mediastinal cyst can occur in adults, though this is also very unlikely in persons in this age group. However, malignant lesions are more likely to produce signs and symptoms of obstruction, compression, or both because they invade or transfix normal mediastinal structures.
Clinical findings associated with these malignant properties include cough, dyspnea, stridor, dysphagia, and even more dramatic findings such as superior vena cava syndrome.
Invasion of the chest wall or pleura by a malignant neoplasm can produce persistent pleural effusions and a significant amount of local pain. Invasion of nearby nerves within the thorax can produce local and referred pain and a variety of other findings such as hoarseness from recurrent nerve paralysis, diaphragmatic paralysis from phrenic nerve paralysis, Horner syndrome from autonomic nerve invasion, and even motor paralysis from direct spinal cord involvement. Pain in the shoulder or upper extremity can occur from invasion of the ipsilateral brachial plexus.
Systemic findings such as weight loss, fever, and malaise also occur.
In von Recklinghausen disease or neurofibromatosis, an inheritable disease, the individual may develop multiple tumors, generally neurofibromas.
Functioning mediastinal pheochromocytomas produce an excess of circulating catecholamines. The hallmark clinical finding in individuals with these neoplasms is hypertension. The hypertension may be persistent, paroxysmal, or persistent with paroxysmal episodes.
Hypertensive crises may occur and may be triggered or exacerbated by anesthesia, trauma, and the onset of labor. The hypertension found in these individuals may be termed malignant and most often is resistant to any standard antihypertensive therapy. It certainly may lead to the usual complications of long-standing or severe hypertension such as stroke, cardiac failure, or renal function abnormalities.
In some patients, paroxysmal episodes can be accompanied by other symptoms, which include headaches, diaphoresis, anxiety, chest pain, palpitations, and pallor. Some patients also have an associated tachycardia.
Marked vasoconstriction from the excessive catecholamine discharge associated with these neoplasms creates a severely volume-contracted state in these individuals. This, in turn, produces the appearance of an elevated hematocrit value.
-
Asymptomatic mediastinal mass found during a routine chest radiograph evaluation of a 34-year-old woman. At surgery, this was found to be a benign neurofibroma.
-
Lateral chest radiograph of a mediastinal mass found during a routine chest radiograph evaluation of a 34-year-old woman. At surgery, this was found to be a benign neurofibroma (same patient as in the image above).
