HEMANGIOPERICYTOMA OF THE KIDNEY

Abstract

The extremely rare tumor of a hemangiopericytoma of the kidney is reported, and some aspects of this tumor discussed. The results are summarirzed as follows:
1) Hemangiopericytoma may arise wherever there are capillaries but is most common in the skin and the subcutaneous tissue. In the literature, however, we could find only 1 case of the kidney in Japan.
2) Final diagnosis must be made histologically. Hematoxylin-eosin stain and silver reticulin stain are necessary.
3) The histologic appearance of this tumor does not indicate whether it is benign or malignant. But clinically this tumor may be malignant. This has been demonstrated by direct extension of tumor tissue, recurrence after excision and also metastases.
4) Symptoms are very uncommon. Pain in the area of the tumor and vague gastrointestinal symptoms may be present, but generally, the only findings is that of a tumor mass.
5) Intravenous and retrograde pyelograms demonstrate distention, elongation and displacement of the pelves and calyces. In our case, “pooling phenomenon” is shown by aortogram. But hematuria is not usual.
6) It is impossible to state whether this tumor arose from the kidney parenchma, or arose from the capsule. In the literature, however, it seems to arise from the capsule, involve and invade the kidney.
7) Treatment of this tumor is primarily complete surgical excision and postoperative radiation therapy.
8) It is thought that a lymph-node disection is not necessary since metastases are hematogenous.