Diffuse nodular interstitial infiltrations with bilateral hilar lymphadenopathy

Lymphocytic interstitial pneumonia(LIP) is an uncommon condition in which the alveolar septa and extra-alveolar interstitial space are markedly expanded by small lymphocytes, plasma cells and histiocytes. Chest radiographs generally show nonspecific patterns with the most common pattern showing bibasilar reticular or reticulonodular infiltrates. Hilar or mediastinal lymphadenopathy and pleural effusions are usually absent. We encountered a 42-year-old female patient who was admitted to hospital because of exertional dyspnea and palpitation. The chest X-ray showed an enlarged bilateral hilar shadow and diffusely increased bronchovascular markings in both lung fields. The chest CT showed diffuse nodular infiltrations with mild septal thickening and combined patchy ground glass opacity in both lungs, and conglomerated mediastinal and bilateral hilar lymphadenopathy. A diagnosis of LIP was made from the tissue pathology taken by a thoracoscopic lung biopsy. The patient showed clinical and radiographic improvement after 3 months of treatment with prednisolone. We report a case of LIP presenting as diffuse nodular interstitial infiltrations with multiple mediastinal and bilateral hilar lymphadenopathy.