Summary

Natural killer (NK)/T-cell lymphomas represent a rare type of lymphoma derived from either activated NK cells or cytotoxic T cells. Most cases with T/NK cell lymphoma present with extranodal manifestations. Primary nodal disease is very rare. The upper respiratory tract is the most common site involved in extranodal disease. Symptoms include epistaxis and nasal obstruction. T/NK cell lymphomas show aggressive and invasive clinical progression, with a poor prognosis. Without treatment, survival is measured in months. We report a case of a 51-year-old male patient with pneumopericardium as a complication of intestinal T/NK cell lymphoma. To the best of our knowledge, this is the first report showing pneumopericardium as a fatal complication of T/NK cell lymphoma. Pneumopericardium should be considered in patients diagnosed with T/NK cell lymphoma presenting with chest pain.