A case of inflammatory pseudotumour of the spleen with EBV infection complicated by idiopathic thrombocytopenic purpura

Abstract

Reports of inflammatory pseudotumour (IPT) of the spleen with Epstein-Barr virus (EBV) infection complicated by idiopathic thrombocytopenic purpura (ITP) are very rare. The pathogenesis of this tumour has remained obscure, with most authors agreeing that IPT of the spleen is a non-neoplastic, reactive condition. IPT of the spleen often poses diagnostic difficulty because it forms an infiltrative mass which has clinical, radiological and gross pathologic features that suggest a malignant lymphoma, vascular malformations, but also inflammatory myofibroblastic tumour (IMT) and inflammatory pseudotumour-like follicular dendritic cell tumour (IPT-FDC). Herein, we report a case of IPT of the spleen with EBV infection in a 51-year-old woman who presented with symptoms of ITP. The results of abdominal ultrasonography and computed tomography (CT) showed the presence of a splenic mass. She had been observed for 12 months with the diagnosis of a possibly benign neoplasm such as haemangioma or granulomatous disease; the tumour grew, necessitating an open splenectomy for diagnostic and curative goals. Histopathologic examination showed an inflammatory pseudotumour with spindle cells positive for EBV by in situ hybridization. When examined immunohistochemically, the spindle cells were focally positive for SMA, vimentin and CD68, and negative for CD21, CD23, CD35 and ALK, thus excluding IMT and IPT-FDC tumour. No evidence of recurrence of thrombocytopenia or subsequent development of other neoplasm was noted 18 months after splenectomy. Splenic IPT can be considered as a benign reactive tumoral lesion. It is important to distinguish it from other conditions using a combination of clinical, histologic, and immunophenotyping findings. We believe that EBV infection may have played a role in the pathogenesis of splenic IPT and the development of thrombocytopenic purpura.