Renal Masses in the Neonate

Abstract

Abdominal masses are frequent in newborn infants, two thirds being renal in origin. After thorough palpation of the abdomen, cystic masses must be differentiated from solid masses by ultrasound examination. The common benign cystic masses include hydronephrosis, multicystic dysplasia, polycystic disease, and adrenal hemorrhage. Solid masses include renal vein thrombosis, a renal ectopic kidney, or horseshoe kidneys. Occasionally, a renal mass may be malignant and correspond to congenital mesoblastic nephroma, Wilms’ tumor, or fetal hamartoma. Whatever the nature of the renal mass, early intervention may save the kidney or the patient.

Renal tumors in infants less than 6 months of age

“…The differential diagnosis for solid tumors includes congenital mesoblastic nephroma, Wilms' tumor, and much less common lesions such as rhabdoid tumor, clear cell sarcoma of the kidney, renal cell carcinoma, angiomyolipoma, and ossifying renal tumor of infancy. [1][2][3][4] CMN is the most common renal neoplasm in neonates and young infants, 3 and this was reflected in our series. Typically, patients with CMN present with an abdominal mass at less than 3 months of age; however, these lesions may be detected prenatally on routine obstetric ultrasound examination.…”

“…2 Hydronephrosis and cystic renal disease will account for most of these masses. The differential diagnosis for solid tumors includes congenital mesoblastic nephroma, Wilms' tumor, and much less common lesions such as rhabdoid tumor, clear cell sarcoma of the kidney, renal cell carcinoma, angiomyolipoma, and ossifying renal tumor of infancy.…”

“…In this younger age group, congenital mesoblastic nephroma (CMN) is the most common renal tumor; however, Wilms' tumor, rhabdoid tumor, clear cell sarcoma of the kidney, renal cell carcinoma, and other rarer lesions also may be found. [1][2][3][4] The typical clinical presentation is an abdominal mass, but sometimes renal tumors in this age group present with hematuria, as an abdominal mass detected on prenatal ultrasound scan, or with manifestations of metastasis (such as hydrocephalus). Furthermore, renal tumors in this age group may be associated with paraneoplastic syndromes, such as hypertension or hypercalcemia.…”

Antenatally detected solid tumour of kidney

“…Approximately two thirds of infantile abdominal masses are of renal origin, and most are benign 4. Hydronephrosis and cystic renal disease will account for most of these masses.…”

Pediatric renal tumors

“…Abdominal masses in infants and children are not a rare occurrence. In the infant, nearly two-thirds of these will be renal in origin and the majority will be benign [1]. The efficient evaluation of these children is critical both for maximal utilization of health care resources and to minimize the duration of the evaluation and stress for the parents.…”