Two cases of primary hemangiopericytoma of the lung are reported. The massive tumors had radiographic features of round or oval contour, homogeneous opacity, well circumscribed smooth outline without calcification, and no compression of the surrounding lung tissue. They were rather homogeneous histologically, well encapsulated, and centrally located, but extended peripherally by replacement, instead of compression, of the pulmonary parenchyma. Review of the literature about 34 other cases suggests these are the usual characteristics of primary hemangiopericytomas of the lungs.
