What are the Symptoms of Medullary Sponge Kidney

Medullary sponge kidney is a congenital renal dysplasia. It is more common among the male and its incidence rate is about 1/5000. The renal function is generally not affected and most patients will be diagnosed because of kidney stone and urinary tract infection between 40 and 50.

It is a benign cystic disease affecting renal medulla. It is not so common in clinic and usually be detected after 20. Patients can have no symptoms at all or have recurrent stones and infections in the urinary tract and its prognosis is good.

Medullary sponge kidney has slow progression and in the early stage there can be no symptoms in clinic. The common symptoms are repeated microscopic hematuria or gross hematuria, urinary tract infection, back pain, renal colic and a few cases might have painless gross hematuria. Such symptoms like infection, bleeding and stones are caused by the retention of urine. In case of urinary tract infections, there can be pyuria. Although there will be decrease of glomerular filtration rate, renal enrichment function as well as renal tubular acidosis, the kidney functions are usually normal and it seldom develops into end stage renal failure. In the end stage, patients will have anemia, loss of salt and azotemia.

In clinic, meduallary sponge kidney is often misdiagnosed because of stones and infections in the urinary tract. KUB and Intraudio Videoenous Urography can help confirm the diagnosis. There are red cells and white cells in routine urine test and pyocyte in case of infections. When the kidneys are damages and patients have renal insufficiency, there will be increase of serum creatinine and urea nitrogen.

If there is no clinical symptoms, patients can have no treatment at all except regular check-up to have close monitoring of the illness progression and kidney functions. The treatments for medullary sponge kidney mainly aim at preventing and controlling complications.