Unusual vascular changes in the red pulp of the spleen accompanying breast carcinoma metastasis

The prevalence of splenic metastasis from carcinomas varies between 2% and 13% in autopsy studies. Most of them are clinically inapparent. We report herein the case of a splenic metastasis revealing breast carcinoma in a 73-year old woman. Splenectomy was performed to correct hypersplenism. Macroscopically, the cut surface of the spleen was uniform and pale. On microscopical examination, the metastatic infiltration involved both red and white pulp as single cells, cords and micro-nodules. Tumor cells were positive for cytokeratin and epithelial membrane antigen (EMA). The breast origin of this splenic metastasis was supported by the increase of CA 15-3 level, and by the appearance of axillary lymphadenopathy. In addition, the red pulp sinuses were obliterated by multiple thrombi at different stages of development and the splenic cords were collagenized. These changes could result from an unusual stromal reaction.