A 17-year-old girl presents with no significant past medical history. She denied a history of fever, chills, night sweats, or weight loss during the 6 months before her office visit. She is a nonsmoker who reports no travel outside of Illinois. She has had the usual respiratory tract infections over the course of her youth. She is referred with the following chest x-rays, which were obtained during admission to the emergency department for abdominal pain, which was subsequently found to be due to appendicitis.

Chest computed tomography (CT) scans of the chest to characterize the abnormality found on chest x-ray.

The differential diagnosis of a paratracheal (middle) mediastinal mass in a young woman includes infection, malignancy, granulomatous disease, bronchogenic cyst, and esophageal duplication cyst. Infectious causes include bacterial, such as tuberculosis, and fungal, such as histoplasmosis. Malignant causes include lymphoma, lung cancer, and esophageal cancer. Noninfectious granulomatous diseases include sarcoidosis and Wegener’s granulomatosis. Histoplasmosis and sarcoidosis frequently present as asymptomatic granulomatous mediastinal lymphadenopathy.

The CT scan finding is most consistent with mediastinal lymphadenopathy; thus, an outpatient mediastinoscopy with biopsy of the enlarged mediastinal lymph nodes is necessary to obtain tissue diagnosis. The specimens should be sent for fungal and tuberculosis culture in addition to histology.