Side of simple renal cysts usually solitary , but also showed a small but multiple or atrial rarely occurs in bilateral , compared with polycystic kidney disease, the clinical manifestations and pathological manifestations are different.

1. Simple ( isolated ) Overview of renal cysts associated
Side of simple renal cysts usually solitary , but also showed a small but multiple or atrial rarely occurs in
bilateral , compared with polycystic kidney disease, the clinical manifestations and pathological
manifestations are different.
Treatment
( 1 ) special treatment :
① When excretory urography and renal tomography X-ray tomography, ultrasound and CT images
failed to make the most of a diagnosis , you can choose for angiography, percutaneous cyst aspiration
and then as the next diagnostic tool , which can also be carried out under ultrasound in the X-ray image
of the monitoring screen monitor . Find the clearest signs of cyst fluid is encouraging , but should do the
pumped fluid cytology . It should also be measured fat content , the fat content is increased in line with
the diagnosis of tumors.
Adequate drainage of the cyst fluid then , and substituting it with a contrast agent . Then radiography at
different position, to show the wall smooth , with or without the presence of vegetation . Withdrawn
before contrast agent injected into the aliphatic ester iodide 3ml cysts , which will further reduce the
accumulation of liquid caused by the change . Introduced in the Bean 1981 to 95 percent alcohol
injected air sac , with this method , he found only one case of recurrence in 29 patients . If only a simple
cyst evacuated approximately majority will relapse . If the pumped fluid is bloody , consider surgical
exploration , so when a serious disease , and even cancer has occurred.
② such as diagnosis, retention cysts may be considered , after a rare case of cystic kidney damage .
③ When the diagnosis is still in doubt , consider surgical exploration. Ambrose , etc. In 1971, when the
majority has been diagnosed with cysts , still prefer surgical exploration. In 55 cases they have done the
surgery . Five cases have been confirmed cancer , accounting for 9 %. Usually only the outer portion of
the renal cyst resection. If severe kidney damage , kidney removal also indications, but it is rare.
( 2 ) the treatment of complications : When the cyst complicated by infection, antibiotic treatment should
be strengthened , despite Muther and Bennett1980 cyst fluid was found in very low concentrations of
antibiotics can be achieved . And they often need to pass through this puncture and drainage . After this
puncture and drainage fails, surgical resection of renal cyst wall section and drainage, also proved to be
quite good effect . Hydronephrosis , the removal of the cyst wall caused by obstruction of the ureter
obstruction can be lifted . Involving the kidneys suggestive of pyelonephritis, urinary tract obstruction ,
then the ureter drainage is not smooth . After excision of the cyst , urinary tract naturally eased the
pressure so that the antimicrobial therapy more effective.
Pathogenesis
Simple renal cysts whether congenital or acquired , it was not clear. Its origins may be similar to
polycystic kidney disease, only a difference in degree . On the other hand , by causing renal tubular

2. obstruction and ischemia, animals can suffer from simple renal cysts. This, in turn suggesting that the
lesions can also be acquired for . With the increase of the cyst , based oppression can damage the
renal parenchyma , but still not so impaired renal function . Part of an isolated cysts can occur just
oppressive to the ureter , causing progressive hydronephrosis, after this situation occurs then be
complicated by infection . Feiner, Katz and Gallo 1980 年 noticed acquired renal cystic disease is
common in long-term dialysis patients. Kessel and Tynes1981 was observed in 2 cases of spontaneous
regression of renal cysts .
Pathological changes
Simple renal cysts often involving kidney lower pole . Cyst symptoms of an average of about 10 cm in
diameter , but a few can be as large as full flank . Cysts usually contain clear amber fluid sac . Thin
wall , cysts often has " blue dome " shape. Even visible wall calcification . About 5% of cysts containing
bloody cyst fluid , which may have papillary carcinoma on the half wall .
Simple renal cysts occur in the surface of the kidney , but can also be located in the deep . When a cyst
located in the deep , its wall on the inner wall of the renal pelvis and renal epithelial tight even light , to
separate them is very difficult, but the cyst was not connected with the pelvis . Microscopy can be found
in the wall with severe fibrosis and glass degeneration, calcification can still see the area near the
kidney tissue fibrosis occurs also under pressure . Many occur in children with simple renal cysts have
been reported , but the huge cyst was rare in children . At this point, the possibility exists must first
exclusive cancer . In urography , a small house of renal cysts and tumors can be confused . Ultrasound
images can be diagnosed even need to line CT and MRI .
Clinical manifestations
( 1 ) Symptoms: Common located flank and back pain is usually intermittent dull . When the bleeding so
that wall expansion , there may be a sudden pain. Gastrointestinal symptoms can occur even while
suspected peptic ulcer or gallbladder disease. Patients may self- discovery abdominal mass , in spite of
a large cyst rare. When a cyst infection, patients often complain of flank pain , malaise and fever .
( 2 ) signs: more than normal physical examination , even in the kidney area or knock and a palpable
mass . If the cyst infection , threatening abdominal tenderness.
( 3 ) laboratory tests: urinalysis mostly normal . Microscopic hematuria is rare. Kidney function tests are
normal, except for the multiple cysts or bilateral nature ( rare ) . Even the side surface of the kidney
extensive destruction , but also because of the contralateral kidney compensatory hypertrophy and
maintain normal total renal function.
(4) X -ray examination : abdominal plain film in the kidney can often see the shadow of swelling or a part
of a mass oppression. Cysts can cause kidney weight or position the shaft torsional lead to kidney
abnormalities . Sometimes the tumor edge stripes can be seen calcification . Excretory urography can
be confirmed. In the intravenous injection of contrast agent after 1 to 2 minutes radiography , showing
increased renal vascular density , and that part of the space occupied by the cyst will not , because

3. there is no blood vessels. Urography continuous radiography showed a mass presence .
A cyst or several surrounding calyx or pelvis often due to depression or bent , and become widened,
flattened lumen even disappear . Oblique or lateral radiographs are also helpful in the diagnosis . When
the mass occupied the pole, ureteral kidney will shift next to the spine . Kidney itself rotation will occur.
By sac fluid or transmission line may be to see the psoas muscle . When conventional urography can
not effectively distinguish opaque when the renal parenchyma , renal tomographic X-ray tomography
may have increased renal vascular contrast with cysts . Occasionally there are relatively non- renal
tumor blood vessels, thus easily confused with cysts . A few cases, the cyst wall tumors may also occur ,
it is necessary to make a further examination in the differential diagnosis .
(5) CT Scan: Identification of renal cysts and tumors , CT is the most accurate . Cyst fluid density similar
to water , and the density of the tumor and normal renal parenchyma similar. After intravenous injection
of contrast agent, renal parenchyma becomes more dense , and the cyst remains unaffected ; cyst wall
and the renal parenchyma there are clear boundaries , while no tumors ; cyst wall is thin , the tumor is
not. In many ways , the identification of cysts and tumors CT is superior puncture fluid judgment.
( 6 ) Renal ultrasound : taking non-invasive diagnostic techniques to identify the substance of renal
cysts and masses when a large proportion of ultrasound . When a match is found cyst ultrasound
images, ultrasound images can be under surveillance, cyst puncture and aspiration of cyst fluid .
( 7 ) isotope scan : a straight line scan shows the mass profile, but it is difficult to distinguish cysts or
tumors. Using technetium scanning tomography can show avascular mass.
( 8 ) In the cyst photography percutaneous cyst aspiration : When checking for the identification of these
cysts and tumors are still in doubt, it is necessary to puncture aspiration.
Complication
Spontaneous infection in simple renal cysts rare , but in the event it is difficult to discriminate with renal
carbuncle . Sometimes the cyst can be bleeding, sudden , can cause pain , bleeding from the cyst wall
may be associated with the cancer . Lower pole renal cyst located and close to the ureter , it can
aggravate hydronephrosis, renal pelvis and urine for oppression can cause back pain. This obstruction
can also make kidney infection.
Differential Diagnosis
( 1 ) Kidney cancer : showed lesions , but prone in deep , causing a more pronounced calyx bent.
Hematuria common, and cysts disappear. When the pressure in the renal tumor above the psoas
muscle in the abdominal plain film can not see the edge of the muscle , and the cyst is still visible.
Evidence of metastasis ( eg on weight loss, fatigue, supraclavicular lymph node enlargement touched ,
chest X-ray showed a metastatic nodules ) , polycythemia occur , hypercalcemia , and ESR are
suggestive of cancer . Need to remember is that cancerous cyst wall change will occur .
If the cancer is renal vein blockage , excretory urography is not clear even without developing .

4. Ultrasound and CT image is always the last to make the differential diagnosis. X-ray tomographic
angiography and renal photography can show rich in blood vessels in the tumor , there is a contrast
agent intensive " pond ", and cyst density is not affected. Proved to be in front of other diseases , all
kidney lesions are assumed to cancer is wise.
( 2 ) polycystic kidney disease : As shown urography , the disease is almost always bilateral , distorted
its own rules has become filled with calyx and pelvis occur. Simple renal cysts are much more isolated
solitary . Polycystic kidney disease is often associated with renal dysfunction and hypertension , and
renal cysts do not.
( 3 ) renal carbuncle : The disease is rare. When collecting history, can be found in skin infections had a
history of fever and local pain before projecting a few weeks . Urography show its similarity with the cyst
and tumor lesions , but inflammation around the affected kidney , the renal contour lumbar muscle
shadow blurred. At this point, more than the fixed kidneys . The patient can be confirmed by comparing
the position of the kidneys in the supine and upright when . Angiography can show an avascular
lesions . 67Ga scan showed inflammation of the nature of the lesion , but the infection of simple renal
cysts may also have a similar performance.
( 4 ) hydronephrosis : signs and symptoms consistent with the performance of simple renal cysts , but
urography is different. Deformation caused by kidney cysts , and hydronephrosis is manifested due to
the obstruction caused by the expansion of the renal pelvis and calyces . Acute or subacute
hydronephrosis due to the increased pressure in the pelvis often produce more localized pain , infection
and because it is easy to express complicated.
( 5 ) renal tumors ( such as adrenal , mixed retroperitoneal sarcoma ) : kidneys can shift , but few make
the invasion and kidney calyceal deformation.
( 6 ) can hydatid disease : its cyst did not communicate with the pelvis, and simple renal cysts is difficult
to identify, because there is not urine and hydatid larvae . Commonly found in X -ray examination of
renal hydatid cyst wall calcification . Helpful when the diagnosis of skin sensitivity test .
Prognosis
The use of ultrasound and CT scan images to make extremely precise diagnosis of simple renal cysts .
In the annual review of swollen observed changes in size, shape and texture of the interior , it is a good
method for ultrasound images . Cancerous performance when feasible CT scan , to be diagnosed , it
can then aspiration of cyst fluid . Most cysts better prognosis.