A CASE OF MALIGNANT FIBROUS HISTIOCYTOMA ORIGINATING IN THE RETROPERITONEAL REGION, IN WHICH RESECTION WAS PERFORMED AGAIN DUE TO PANCREATIC AND PULMONARY METASTASIS TWO YEARS AFTER THE FIRST OPERATION

We encountered a case of malignant fibrous histiocytoma (MFH) originating in the retroperitoneal region, in which the tumor was surgically resected but pancreatic and pulmonary metastases occurred two years after the first operation, and the metastatic foci were resected. The patient was a 56-year-old woman whose course after retroperitoneal MFH resection had been followed up at the outpatient clinic. The patient began to complain of epigastralgia two years after the operation. Pancreatic and pulmonary metastases were detected on detailed examination, and the metastatic foci were resected simultaneously. The tumor was histopathologically diagnosed as metastatic malignant fibous histiocytoma. MFH originating in the retroperitoneal region is rarely accompanied by subjective symptoms, and is often detected as a huge mass. Accordingly, the incidence of local recurrence and metastasis is higher than MFH originating in other regions, resulting in a worse prognosis. Preferential sites of metastatic foci include the lung, liver and bone. Pancreatic metastasis, as observed in our patient, is extremely rare. Accessory therapies such as radiotherapy and chemotherapy have been performed more frequently, but no established therapy is available. Effects for early detection of the recurrence should be made through careful postoperative follow-up, in order to resect the metastatic foci in the earliest stage possible.