Megaureter and hydronephrosis: Consequences of ureteric dysfunction

Abstract

The prevalence of “megaureter” among children can be as high as 20-25% and can be bilateral or unilateral; in some cases, the contralateral kidney is either absent or dysplastic. Megaureters can be categorized as obstructed, refluxing, obstructed and refluxing, or neither obstructing nor refluxing. Megaureter is likely to either transiently or permanently involve the kidneys, resulting in hydronephrosis or other medullary and cortical derangement. During routine student dissection of an 86-year-old female donor who died of atherosclerotic cardiovascular disease, we observed the presence of large ureters on both kidneys with the right-side ureters comparatively much larger than the left side. The upper and lower lobes of the right kidney were drained by independent ureters, which were encased in a thin, membranous connective tissue structure. Additionally, we also observed thinning of the renal cortex, renal pelvis, and caliceal dilation with total loss of medulla and lack of corticomedullary delineation. Importantly, reproductive structures such as uterus, fallopian tubes, ovaries. cervix and vagina were normal. This paper, in addition to providing a description of what was observed on dissection, will discuss various causes, pathophysiology, and alterations in the matrix composition of the ureter and kidney.