RT Journal Article SR Electronic T1 Spontaneous regression of natural killer cell lymphoma JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 647 OP 650 DO 10.1136/jcp.2008.062976 VO 62 IS 7 A1 Y Isobe A1 N Aritaka A1 M Sasaki A1 K Oshimi A1 K Sugimoto YR 2009 UL http://jcp.bmj.com/content/62/7/647.abstract AB Spontaneous tumour regression is extremely rare in aggressive lymphoma. A case of natural killer (NK) cell lymphoma with cutaneous manifestation showed an indolent clinical course, and the relapsed nodular lesion disappeared spontaneously without any treatment. Although only small number of T cells were present in the primary skin lesion, there was massive CD8-positive cytotoxic T cell infiltration in the relapsed lesion. This is believed to be the first report of an abscopal effect on NK cell lymphoma. Infiltration of cytotoxic T cells strongly suggests immunological attack against the lymphoma cells.