What Is Medullary Sponge Kidney?

Medulla cavernous kidney refers to congenital dysplasia mainly manifested by cystic dilatation of the medullary collecting duct, referred to as cavernous kidney. Middle-aged and young people are sporadic, most of them are sporadic, and a few are familial aggregation. Cystic dilatation of the nipple and collecting ducts of the renal pyramid is a characteristic manifestation, and may be accompanied by infection and urinary calculus formation.

Basic Information

Visiting department: Nephrology
Multiple groups: Young and middle-aged

Common causes: Congenital dysplasia
Common symptoms: Hematuria, urinary tract infection, renal calcium and kidney stones, impaired renal tubular function, etc.

Causes of medullary sponge kidney

Most of them are sporadic, have no family history, and there is still no clear evidence of heredity, but 2-year-old children have been found, and the disease is often accompanied by other congenital diseases (such as horseshoe kidney, hypertrophy, etc.), Therefore, most scholars believe that the disease is a congenital dysplasia.

Clinical manifestations of medullary sponge kidney

1. Hematuria is the most common symptom. Most patients with this disease have intermittent microscopic hematuria. A small number of patients develop painless gross hematuria, which is often accompanied by hypercalciuria and dilated tubule fragility. The symptoms are markedly persistent. hematuria.
2. Urinary tract infection is also a common clinical manifestation. Pyelonephritis can be the first symptom of this disease. Retention and stones in dilated mastoid tubules become the main cause of repeated urinary tract infections. Due to infiltration of medullary monocytes, asymptomatic bacterial urine can sometimes occur, and it should be distinguished from leukocyte urine caused by urinary tract infection.
3. Renal calcification and kidney stones Renal calcification is very common in patients with this disease, and about half of them have renal parenchymal calcification. Stones occur mostly in both kidneys and are multiple. The composition of the stones is similar to that of ordinary urinary stones. Stones can cause related clinical manifestations such as hematuria, low back pain, and there are no obvious symptoms. They are only found by accident during physical examination.
4. Impaired renal tubular function such as urinary concentrating dysfunction, partial or complete distal renal tubular acidosis, hypocitrate, etc.
5. Others are often accompanied by other congenital diseases, which may be accompanied by hypertrophy, congenital pyloric stenosis, horse side syndrome, horseshoe kidney and so on.

Medullary sponge kidney test

1. Urine routine laboratory tests show urinary red blood cells and leukocytosis.
2. Imaging examination (1) Ultrasound: Non-specific sonograms that can detect calcifications and stones are manifested as enhanced medullary echo, but due to the small cysts in this disease, ultrasound is sometimes difficult to clearly show.
(2) X-ray examination: X-rays of the abdomen can provide diagnostic clues to facilitate the observation of the occurrence and development of kidney stones and calcification in patients. It shows normal or slightly enlarged kidney volume, smooth kidney surface, and cystic calcifications. If combined with stones, multiple small stones in bilateral or unilateral renal parenchyma can be seen, with a diameter of 2 to 5 mm, round, round or not. Regular shape.
3. Intravenous pyelography is the preferred diagnostic method, which can more intuitively show the dilated collecting ducts, which are manifested as abnormal shadows outside the renal calyces, such as dilated renal tubules, stones, and dense cystic shadows.

Diagnosis of medullary sponge kidney

Middle-aged and young people who have recurrent hematuria, especially gross hematuria with urinary tract infection, sometimes find that small stones are discharged or even renal colic should be diagnosed as the disease. Combining imaging features such as laboratory tests, X-rays, and intravenous pyelography can confirm the diagnosis.

Differential diagnosis of medullary sponge kidney

It needs to be distinguished from renal tuberculosis, pyelone cyst, renal tubular regurgitation, asymptomatic bacterial urine, renal papillary necrosis, and renal calf diverticulum, etc. It is mainly identified by typical imaging characteristics, clinical characteristics, and genetic methods.

Medullary sponge kidney treatment

There is no special cure for this disease. Once diagnosed, the main complications should be actively prevented and treated. When there are no special clinical symptoms or complications, no special treatment is needed, and regular follow-up observation can be performed.
1. General treatment is usually recommended that patients drink more water, eat more fruits and vegetables, low salt, moderate protein diet, control high calcium diet.
2. Drug therapy Use caution with stone-releasing drugs, which can be treated with potassium citrate, which can effectively reduce the urinary calcium excretion and the recurrence rate of stones, while increasing the bone density of patients; if still unable to effectively reduce the calcium in urine, you can use thiazide diuretics Patients with normal urinary calcium and calculi can take phosphate drugs orally; antibiotics should be used for infection.
3. Surgical treatment For patients with frequent recurrence of stones and symptomatic patients, laser nipple incision should be performed to remove small stones at the nipple canal, which can effectively control the pain caused by stones.