Retroperitoneal Fibroxanthogranuloma

A case of retroperitoneal FXG involving the intestine in a 53 year old man is reported. The clinical signs were vomiting, diarrhoea and severe pain in the lower right abdomen. Histologically the lesion was characterized by a mixture of fibroblasts, histiocytes, foamy histiocytes and multinucleated Touton cells without frankly anaplastic pictures and by an inflammatory infiltrate composed of lymphocytes, plasmacells and polymorphonuclear leukocytes. All the cells were in and surrounded by a dense fibrous network. The case may be regarded as a true neoplasia, potentially malignant, in spite of the absence of overt cytological malignancy.