Hemangiopericytomas in male pelvis.

All cases of hemangiopericytomas involving the male pelvis which have been reported in the English literature with clinical data have been reviewed. Their clinical features, roentgenographic findings, pathologic features, and treatment are presented with an illustrative case. The tumor is an aggressive neoplasm which characteristically produces late local recurrences or metastases. Since the clinical behavior cannot be reliably predicted from its histologic appearance, all must be regarded as malignant. Primary treatment should be en bloc excision since a high recurrence rate results when simple enucleation or excision is performed. Long-term follow-up is mandatory, and local recurrences or metastases should be resected whenever feasible. Radiation and chemotherapy may convert a nonresectable lesion into a resectable one and provide significant palliation.

An animal model for the growth of human tumor cell lines.

Newborn rats were thymectomized at less than 24 hr of age and received antilymphocyte serum and heterologous human tumor cells. This model allows the growth of large primary tumors with a high metastatic percentage. This model may be applicable to the study of a wide variety of genitourinary tumors.