bilateral hilar lymphadenopathy bilateral hilar lymphadenopathy bilateral hilar lymphadenopathy is a bilateral enlargement of the lymph nodes of pulmonary hila. it is a radiographic term for the enlargement of mediastinal lymph nodes and is most commonly identified by a chest x-ray. ct scan of the chest showing bilateral lymphadenopathy in the mediastinum due to sarcoidosis. causes the following are causes of bhl: sarcoidosis infection tuberculosis fungal infection mycoplasma intestinal lipodystrophy (whipple's disease) malignancy lymphoma carcinoma mediastinal tumors inorganic dust disease silicosis berylliosis extrinsic allergic alveolitis such as bird fancier's lung less common causes also exist: eosinophilic granulomatosis with polyangiitis human immunodeficiency virus extrinsic allergic alveolitis adult-onset still's disease