RT Journal Article SR Electronic T1 Late diagnosis: a case of rapidly progressive extranodal NK/T cell lymphoma, nasal type JF BMJ Case Reports FD BMJ Publishing Group Ltd SP bcr-2017-221019 DO 10.1136/bcr-2017-221019 VO 2018 A1 Hiroyuki Mori A1 Kei Ebisawa A1 Mitsushige Nishimura A1 Kenji Kanazawa YR 2018 UL http://casereports.bmj.com/content/2018/bcr-2017-221019.abstract AB Extranodal natural killer (NK)/T cell lymphoma, nasal type is a condition that has poor prognosis. Accurate diagnosis of lymphoma is made by pathological findings. We report a case of extranodal NK/T cell lymphoma, nasal type affecting the lung and liver and which was difficult to diagnose because of negative biopsy results from multiple sites. A 39-year-old man who had dry cough and fever for 1 month was referred to our hospital. He had pancytopenia and elevated serum levels of lactate dehydrogenase and soluble interleukin-2 receptor. Hepatosplenomegaly and multiple lung nodules were found on imaging study. Specimens of bronchoscopic lung, percutaneous liver, bone marrow and random skin biopsies were all negative. Open lung biopsy was not definitive. Unfortunately, disease progression was rapid and fatal before results of pleural fluid cytology and a second liver biopsy showed extranodal NK/T cell lymphoma, nasal type. This report focused on diagnostic planning for rapidly progressive extranodal NK/T-cell lymphoma, nasal type.