Mesenteric solitary fibrous tumour containing metastasis from breast carcinoma: an unusual example of tumour to tumour metastasis

Abstract Tumour to tumour metastasis is a relatively rare but well documented phenomenon. The most frequent donor tumour is lung carcinoma, and renal cell carcinoma is by far the most common recipient. Here we present a case of a 46-year-old man operated for a mesenteric tumour, which showed histological and immunohistochemical features of a solitary fibrous tumour. However, on section contained a 3.5 mm focus of an epithelial component. After a search in the past medical records it was known that the patient had been operated 3 years earlier for breast carcinoma. The epithelial component in the present tumour showed similar histological and immunohistochemical features. This is the first example of a tumour to tumour metastasis where breast carcinoma has metastasized to mesenteric solitary fibrous tumour.