A 34-year-old woman comes to the office due to vague chest discomfort. She has no other medical conditions, although she has recently had several upper respiratory tract infections. Temperature is 37.2 C (99 F), blood pressure is 122/78 mm Hg, pulse is 70/min, and respirations are 16/min. The patient is alert and in no distress. The lungs are clear to auscultation bilaterally. Heart sounds are normal and without murmurs. The abdomen is soft and nondistended. ECG shows a normal sinus rhythm. Chest x-ray reveals an enlarged mediastinum. CT scan of the chest reveals a mass in the middle mediastinum. Which of the following is the most likely diagnosis in this patient?

Question

A 34-year-old woman comes to the office due to vague chest discomfort.  She has no other medical conditions, although she has recently had several upper respiratory tract infections.  Temperature is 37.2 C (99 F), blood pressure is 122/78 mm Hg, pulse is 70/min, and respirations are 16/min.  The patient is alert and in no distress.  The lungs are clear to auscultation bilaterally.  Heart sounds are normal and without murmurs.  The abdomen is soft and nondistended.  ECG shows a normal sinus rhythm.  Chest x-ray reveals an enlarged mediastinum.  CT scan of the chest reveals a mass in the middle mediastinum.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d916_31a5_bc81_bb142d9f8689_MD0003_00 This patient with vague chest discomfort, frequent upper respiratory infections, and a middle mediastinal mass most likely has a bronchogenic cyst. Mediastinal masses are categorized according to their location within the anterior, middle, or posterior mediastinal compartments. Most sources define the middle compartment as the space between the anterior pericardium and the ventral surface of the thoracic spine; it contains the heart and great vessels, trachea and main bronchi, esophagus, pericardium, and lymph nodes. Masses that arise from these structures may include the following: Lymphoma or lymphadenopathy (most common), with a broad differential of mediastinal lymphadenopathy that includes sarcoidosis, metastatic lung cancer, and granulomatous infections Benign cystic tumors, including bronchogenic cysts, pericardial cysts, and enteric cysts Vascular masses, including aortic aneurysms and aortic arch abnormalities Esophageal tumors, including large esophageal cancers with extraesophageal invasion Bronchogenic cysts, the most common type of benign cystic tumor, typically arise from anomalous budding of the foregut during congenital development of the tracheobronchial tree. In infancy or adulthood, affected patients may become symptomatic with chest discomfort and nonspecific respiratory symptoms such as recurrent coughing or frequent respiratory infections. CT scan of the chest with intravenous contrast can usually be used to confirm the diagnosis. (Choice B) Neuroblastoma and other neurogenic tumors (eg, schwannoma, neurofibroma) that occur at the level of the thoracic vertebrae can present with chest discomfort. However, they are generally located in the posterior (vs the middle) mediastinum. MRI is often used to evaluate spinal involvement of neurogenic tumors. (Choices C, D, and E) Retrosternal thyroid tissue, teratoma, and thymoma can occur as mediastinal masses and cause chest discomfort and compressive symptoms (eg, cough, dyspnea); however, these masses typically arise in the anterior (vs the middle) mediastinum. In addition, paraneoplastic syndromes (myasthenia gravis being the most common) are common in patients with thymoma. Educational objective: Mediastinal masses are categorized according to their compartments (ie, anterior, middle, posterior). The middle compartment contains the heart and great vessels, trachea and main bronchi, esophagus, pericardium, and lymph nodes. Middle compartment masses may include bronchogenic cysts, which arise from congenital, anomalous budding of the foregut and can cause chest discomfort and nonspecific respiratory symptoms. References: A diagnostic approach to the mediastinal masses. (http://www.ncbi.nlm.nih.gov/pubmed/23225215)

A 34-Year-Old Woman Comes to the Office Due to Vague