The Pyelographic and Roentgenologic Diagnosis of Renal Tumors

TUMORS of the kidney, comprising neoplasms and cysts, are of wide histologic variety. The more common newgrowths include hypernephroma, adenoma, fibroma, and primary or secondary carcinoma and sarcoma. Among the rarer neoplasms are lipoma, hemangioma, fibromyoma, rhabdomyoma, and other mixed forms. Cysts of the kidney may be single or multiple, the latter usually being bilateral. Notwithstanding their histologic diversity, clinically important tumors of the kidney are rare. Efficient diagnosis of renal tumors is by no means simple and direct, but is arrived at by a more or less intricate process of confirmation and exclusion, the final decision usually requiring a correlation of the clinical, roentgenologic, cystoscopic, and laboratory findings. In this process the X-ray findings play an important, often decisive, role. Roentgenologic methods of examination consist of simple roentgenography, pneumoradiography, pneumoperitoneal roentgenography, and pyelography. Simple Roentgenologic Signs In cases of renal tumor simple radiography may reveal, (1) symmetrical enlargement of the renal shadow, (2) local projections of its contour, (3) areas of moderately increased density within a renal shadow of normal size and form, (4) partial or complete concealment of the renal shadow by the shadow of the tumor, or (5) localized densities due to calcified areas in the tumor, or to calculi which are sometimes associated with the tumors. In several cases of hypernephroma, we have noted dense fimbriated streaks of calcification, unlike those observed in any other condition, and this sign may prove of diagnostic value. Obviously, none of the other manifestations mentioned can be pathognomonic of renal tumor. Symmetrical enlargement of the renal shadow may be due to a “large white kidney”; calculi are not necessarily associated with tumor, and, if present, their shadows are likely to be regarded as representing the only lesion; the other abnormal shadows may result from extrarenal tumors. Vague shadows in the renal area, often present under normal conditions, are a possible source of deception. On the other hand, a renal tumor of clinical moment may not be demonstrated by a simple roentgenogram. When an abdominal tumor is known to exist, examination of the stomach with the opaque meal and of the bowel with the meal or enema will aid in determining its relation or non-relation to the kidney. A tumor of the stomach or intestine will usually manifest diagnostic signs. A gross tumor of the kidney is likely to displace the adjacent segment of the colon, or to thin its opaque contents by pressure, but extrarenal tumors may produce identical signs. Roentgenograms showing metastasis in the chest or osseous system sometimes furnish the first clew to an unsuspected malignant tumor of the kidney, and the frequency of such metastasis from renal embryomas in children should be kept in mind.