RESUMEN
Lymphocytic interstitial pneumonia (LIP) is a benign lymphoproliferative disorder characterized histologically by diffuse infiltration with predominantly mature lymphocytes, plasma cells and reticuloendothelial cells in the alveolar septae and along the lymphatic vessels. LIP is an uncommon disease frequently associated with autoimmune diseases such as Sj?gren's syndrome, systemic lupus erythematosus, chronic active hepatitis, thyroiditis, myasthenia gravis, autoimmune hemolytic anemia and Human Immunodeficiency Virus (HIV) or Epstein- Barr virus (EBV) infection. LIP can progress to pulmonary or systemic lymphoma. LIP in children has variable disease courses such as spontaneous resolution, episodic worsening or progression to frank respiratory failure. Intravenous immunoglobulin and corticosteroids yield variable results, and some children may respond to them for several years. We report herein a case of EBV-associated, HIV-negative LIP diagnosed by thoracoscopic lung biopsy and a clonality study in a 5 year-old boy who was admitted with recurrent coughing and dyspnea. The patient was treated and fully recovered with methylprednisolone and high dose acyclovir. At the 3-year follow-up, he showed no clinical symptom despite increased EBV copy in bronchoalveolar lavage and progressive bronchiectasis in the right middle lobe.