Vol. 116, November Printed in U.S.A.

THE JOURNAL OF UROLOGY

Copyright © 1976 by The Williams & Wilkins Co.

RETROPERITONEAL FIBROXANTHOSARCOMA: REPORT OF A CASE FRANCIS J. Y. HAHN

AND

ROLF L. SCHAPIRO

From the Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa ABSTRACT

The clinical and roentgenographic manifestations of a rare retroperitoneal fibroxanthosarcoma are presented and briefly discussed. Fibroxanthosarcoma is a rare malignant neoplasm of soft tissues. Kempson and Kyriakos emphasized the rarity of this disease in their report of only 28 cases seen during an 18-year period. 1 Although none of the tumors in their series was in the retroperitoneum, the occurrence at this site has been reported

CASE REPORT

A 64-year-old previously healthy man was referred to the hospital for evaluation of pain and weakness in the left thigh. He had been hospitalized elsewhere 4 months ago and radio-

A, plain and pyelographic radiograms show equivocal displacement of left kidney and definite segmental displacement of both left ureters. B, mild scoliosis and destruction of left pedicle, left superior articulating facet, left transverse process and centrum of third lumbar vertebra (closed arrow). Associated left paraspinal soft tissue mass is apparent (open arrows). C, vascular study shows possible displacement of aorta to right, hypertrophy of proximal segments of third and fourth lumbar arteries and segmental draping and encasement of third lumbar artery. Tumor neovascularity with early venous filling is apparent (curved arrow). Selective lumbar arteriography would have been helpful in showing greater detail but was unsuccessful unfortunately because of extensive arteriosclerotic disease of aorta and iliac vessels.

in at least 3 patients. 2 While angiographic manifestations of retroperitoneal tumors have been reported previously, 3- 5 to our knowledge this is the first report of the type of neoplasm discussed herein. Accepted for publication April 22, 1976.

graphic examinations of the spine, pelvis and hips were reported as normal except for degenerative changes. A left inguinal hernia was repaired but failure of symptomatic improvement resulted in the present hospitalization. Physical findings were normal except for hypoesthesia and hypalgesia of the

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anterior left thigh, and muscle atrophy of the left lower extremity. Angiographic confirmation of a malignant left paraspinal mass was achieved after detection of the lesion on spinal and urographic examinations (see figure). At operation a fist-sized tumor beneath the left psoas muscle adhered firmly to the third lumbar vertebra and was biopsied at several sites. The histologic diagnosis was fibroxanthosarcoma. The patient returned to his home town and received palliative cobalt therapy (3,700 rads at the mid. plane), which did not affect the tumor size nor yield significant symptomatic relief. He was last seen 5 months postoperatively, at which time his general physical condition was unchanged. DISCUSSION

Fibroxanthosarcoma is a distinctive malignant fibrous histiocytoma, which can be distinguished histologically from other soft sarcomas. Although this tumor presumably can occur at any anatomic location, the majority appear in the soft tissues of the extremities, particularly the thighs and chest wall. At least 3 retroperitoneal fibroxanthosarcomas have been recorded previously in the pathology literature and all 3 cases were characterized by initial local invasion of the spleen, kidney, adrenal or liver and ultimate widespread metastases to the lymph nodes, lungs, bone marrow and heart. 2 This neoplasm involves fat tissue primarily but extension into skeletal muscle and bone is common. Regional lymph nodes, lung and bone appear to be the most common sites of metastases but local recurrence after wide local excision has a much greater probability (approximately 50 per cent) of occurring. Because of the rarity of this tumor, the most efficacious therapeutic approach is not known. Despite this tumor's predilection for extremities, local wide excision rather than amputation has been suggested as the most reasonable initial therapy since

local recurrence rather than distant metastasis represents the most probable sequela. 1 Therefore, amputation is reserved for unusually large tumors or for repeated recurrences of a previously locally resected tumor. Malignant fibroxanthosarcoma has been reported in children as well as in older patients and, most commonly, it is detected after the age of 40 years. The angiographic manifestations and the differential diagnosis of non-visceral retroperitoneal tumors have been discussed by several authors. 3• 5 Our case demonstrates some of the characteristic findings of tumor in this portion of the retroperitoneal space, including hypertrophy of the proximal third and fourth lumbar arteries, stretching of these vessels, encasement (particularly of the third lumbar artery) and tumor neovascularity with early venous or sinusoidal filling. These findings are not helpful in determining the specific histologic diagnosis and do not differ from similar findings attributable to other, more common retroperitoneal malignancies. However, they strongly suggest a malignant process, which in this case was evident on the plain radiograms. REFERENCES 1. Kempson R. L. and Kyriakos, M.: Fibroxanthosarcoma of the soft

2. 3. 4. 5.

tissues. A type of malignant fibrous histiocytoma. Cancer, 29: 961, 1972. Rosas-Uribe, A., Ring, A. M. and Rappaport, H.: Metastasizing retroperitoneal fibroxanthoma (malignant fibroxanthoma). Cancer, 26: 827, 1970. Kahn, P. C.: Retroperitoneal arteriography in adults. In: Angiography, 2nd ed. Edited by H. L. Abrams. Boston: Little, Brown and Co., pp. 1187-1200, 1971. Lowman, R. M., Grnja, V., Peck, D. R., Osborn, D. and Love, L.: The angiographic patterns of the primary retroperitoneal tumors. The role of the lumbar arteries. Radiology, 104: 259, 1972. Smith, A. M. and Becker, J. A.: Malignant mesenchymoma of the retroperitoneum. Amer. J. Roentgen., 104: 389, 1968.