Search results
Results From The WOW.Com Content Network
Metanephric adenoma (MA) is a rare, benign tumour of the kidney, that can have a microscopic appearance similar to a nephroblastoma (Wilms tumours), [1] or a papillary renal cell carcinoma. It should not be confused with the pathologically unrelated, yet similar sounding, mesonephric adenoma .
During the fifth week of gestation, the mesonephric duct develops an outpouching, the ureteric bud, near its attachment to the cloaca. This bud, also called the metanephrogenic diverticulum, grows posteriorly and towards the head of the embryo. The elongated stalk of the ureteric bud, called the metanephric duct, later forms the ureter.
The metanephrogenic blastema or metanephric blastema (or metanephric mesenchyme, or metanephric mesoderm) is one of the two embryological structures that give rise to the kidney, the other being the ureteric bud. The metanephric blastema mostly develops into nephrons, but can also form parts of the collecting duct system.
The collecting ducts descend again into the medulla and fuse to wider collecting ducts, which pass through the inner medulla. [ 68 ] [ 69 ] Based on the location of the renal corpuscle in the cortex, nephrons are classified into 3 types: superficial (closer to the renal capsule), midcortical (in the middle part of the cortex) and juxtamedullary ...
Each metanephric kidney is characterized by a large number of nephrons and a highly branched system of collecting tubules and ducts, [28] that open into the ureter. [48] Such branching in the metanephros is unique in relation to the pronephros and mesonephros. [ 44 ]
A hydronephrotic kidney may present as a palpable abdominal mass in the newborn, and may suggest an ectopic ureter or ureterocele. In older children, ureteral duplication may present as: [citation needed] Urinary tract infection – most commonly due to vesicoureteral reflux (flow of urine from the bladder into the ureter, rather than vice versa).
Typical signs and symptoms of Wilms' tumor include the following: [citation needed] a painless, palpable abdominal mass; loss of appetite; abdominal pain; fever; nausea and vomiting; blood in the urine (in about 20% of cases) high blood pressure in some cases (especially if synchronous or metachronous bilateral kidney involvement) Rarely as ...
The mechanism of multicystic dysplastic kidney is a result of an abnormal induction of metanephric mesenchyme. This could be a result of a formation difficulty of the mesonephric duct . Some mutations in genes associated with renal dysplasia (in syndromes) have been determined.