LAUSR

Department of Gastroenterology, Grand Hopital de Charleroi, Gilly, Catholic University of Louvain, Brussels, Pathology, Institut de Pathologie et de Génétique (IPG), Gosselies, and Department of a Gastroenterology, UCL Saint Luc University Hospital, Brussels, Belgium 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 Question: A 77-year-old woman was referred for continuous left upper quadrant abdominal pain and a hypointense splenic mass on T2-weighted magnetic resonance imaging sequences of the spine, ordered for suspicion of degenerative disc disease. Clinical examination and bloodwork were normal. Her history was relevant for abdominal contusion during a car crash 30 years ago, but no splenic lesion was found on surgical exploration at that time. A computed tomography scan showed a well-defined, 12 9 6-cm lesion with a hypodense necrotic center and isodense peripheral tissue that enhanced after contrast injection, amidst an otherwise normal appearing spleen (Figure A, B). No distant lesions were found. Because the lesion’s size had increased compared with a scan from 2 years earlier and considering a potential malignant process, total splenectomy was performed. Histology revealed a well-circumscribed encapsulated mass consisting of a chronic inflammatory infiltrate (mostly lymphocytes and plasmacytes accompanied by macrophages and a few giant cells) and spindle cells with mild atypia (Figure C, hematoxylin-eosin stain) surrounding a necrotic center. On immunohistochemistry, the atypical spindle cells expressed smooth muscle actin, CD 35 (Figure D) and marked positive for Epstein-Barr virus RNA after in situ hybridization (Figure E).