Hepatic scintiangiography in malignant parasitic tumors.

Occasionally malignant tumors form a para sitic relationship with surrounding organs, de riving their blood supply from vessels feeding that organ without histologic evidence of “in vasion―. Since radiopaque angiography relies upon identification of the feeding vessel to a tumor to define its location and origin, the true nature of a parasitic tumor may not be detected and a mistaken diagnosis of metastases to that organ made. This incomplete information might dissuade a surgeon from operating on a resect able tumor. In the diagnosis of malignant tu mors in and around the liver, radioisotopic scintiangiography reveals filling of the tumor vessels resulting in a “vascular blush―. In gen eral, intrahepatic lesions associated with a vas cular blush have a corresponding well-defined area of decreased radioactivity on the static scintiphotograph. However, a parasitic tumor may not produce a decrease in activity on the static scintiphotograph to correspond to the vascular blush on the scintiangiogram. This would indicate that the lesion was extrahepatic and, in conjunction with the radiopaque an giogram, indicate the true nature of the lesion. This phenomenon is reported in a patient with hypernephroma. Radiopaque angiography, ra dioisotopic scintiangiography, and static scm tiphotography were performed and resulted in the proper preoperative diagnosis.