This patient's symptoms of dry cough and malaise for 2 months with findings of bilateral hilar adenopathy on chest x-ray strongly suggest sarcoidosis.  Sarcoidosis is a chronic multisystem disorder due to noncaseating granulomatous inflammation.  It typically occurs in young adults, is 3-4 times more common in African Americans, and affects more women than men.  Sarcoidosis is frequently detected incidentally on chest x-ray, and bilateral hilar adenopathy is the first manifestation of disease in 50% of patients.  It can also present with symptoms of cough, dyspnea, fever, fatigue, and weight loss.

Definitive diagnosis requires consistent radiographic and clinical findings, and a biopsy demonstrating noncaseating granulomas.  Bronchoscopy with transbronchial biopsy is often performed to obtain tissue diagnosis.  If there is evidence of systemic involvement, more accessible sites such as peripheral lymph nodes or cutaneous lesions can be biopsied.  Patients with incidental bilateral hilar adenopathy are typically monitored without biopsy unless symptoms develop.

(Choice A)  Allergen-induced bronchospasm occurs in asthma.  Patients typically present with cough and intermittent dyspnea (absent in this patient).  Hilar adenopathy is not a typical finding on chest x-ray.

(Choice C)  Loss of elastin in the lung matrix occurs in alpha-1-antitrypsin (AAT) deficiency, leading to emphysema.  Nonsmoking patients with AAT typically present in their mid-40s with dyspnea, cough, and sputum production.  Chest x-ray reveals hyperinflation, and bilateral hilar adenopathy is not a typical finding.

(Choice D)  Necrotizing pulmonary vasculitis occurs in granulomatosis with polyangiitis (formerly Wegener granulomatosis).  Fever, weight loss, and rhinosinusitis are commonly seen on presentation.  Pulmonary nodules and alveolar consolidation are typical findings on chest x-ray but are not present in this patient.

(Choice E)  Pulmonary venous congestion occurs in patients with congestive heart failure.  Characteristic chest x-ray findings include cardiomegaly, cephalization of pulmonary vessels with prominent vascular markings, and pleural effusions, which are not present in this patient.

(Choice F)  Pulmonary embolism typically is accompanied by chest pain and dyspnea, and hilar adenopathy on chest x-ray is not typically seen.

Educational objective:
Sarcoidosis typically affects young adults and is more common in African Americans.  It is often discovered incidentally on routine chest x-ray by the presence of bilateral hilar adenopathy.  The underlying histopathologic lesion is noncaseating granulomas on tissue biopsy.