|Year : 2002 | Volume
| Issue : 2 | Page : 184-185
Spontaneous rupture of a simple renal cyst
Mahesh Rao, K Natarajan, Arun Chawla, SJ Philipraj, K Sasidharan
Division of Urology, Kasturba Medical College, Manipal, India
Division of Urology, KMC, Manipal, Karnataka - 576 119
Source of Support: None, Conflict of Interest: None
Keywords: Spontaneous Rupture of Renal Cyst
|How to cite this article:|
Rao M, Natarajan K, Chawla A, Philipraj S J, Sasidharan K. Spontaneous rupture of a simple renal cyst. Indian J Urol 2002;18:184-5
| Introduction|| |
A simple cyst is a discrete lesion, occurring within the kidney or on its surface, lined by a single layer of flattened cuboidal epithelium, filled with clear or straw-coloured fluid and not connected to any part of the nephron.  Spontaneous rupture of renal cysts occurs infrequently. Accurate interpretation of the radiographic findings is important in making a correct diagnosis of this unusual and frequently self-limiting process.
| Case Report|| |
A 25-year-old recently married female presented with an acute continuous right loin pain of 2-days' duration. There was no other contributory urinary symptoms, trauma or comorbid illnesses. Physical examination revealed a large, ill-defined, retroperitoneal cystic mass, occupying the right lumbar, iliac and hypochondriac regions.
On further evaluation with ultrasonography, a large perinephric cystic collection was found extending from the right sub-hepatic space to the iliac fossa, with the kidney being pushed medially and with mild pelvicalyceal dilatation. CT scan corroborated the above findings [Figure - 1].
A right bulboureterogram disclosed a medially displaced kidney with distinctly splayed upper and middle calyces [Figure - 2]. Percutaneous drainage of right perinephric space yielded immediately 300 ml straw-coloured fluid and altogether ceased after four days. The drainage tube was removed and the patient was discharged with the intent of future review.
CT scan a month later revealed substantial reaccumulation of fluid in the right perinephric space. Exploratory findings were consistent with rupture of a simple renal cyst into perinephric territory. The cyst was excised to effect a complete cure.
| Discussion|| |
The clinical & radiological data in the case reported here is suggestive of a spontaneous rupture of a simple renal cyst. There are sporadic reports in the literature of documented cases of spontaneous rupture of simple cyst into the perinephric space. Such perinephric ruptures of simple renal cyst need cross-sectional imaging (CT scan) for proper delineation. 
The pathogenesis of cyst rupture operates by four different mechanisms; traumatic, infective. increase in intrapelvic pressure and alterations in fluid dynamics.  The mechanism of spontaneous rupture can be explained by the last three hypotheses. Inflammatory changes associated with bacterial infection may weaken the cyst wall as well as produce a rise in intracystic pressure resulting in cyst rupture. Idiopathic alterations in the dynamics of the cyst fluid could increase intracystic pressure with subsequent expansion, thereby producing a tear of cyst wall and rupture. This mechanism could have been responsible for the cyst rupture in this case as bacterial infection and distal obstruction raising intrapelvie pressure were not demonstrable.
Once the correct diagnosis has been established, management is usually conservative and may be supplemented with antibiotic coverage. Surgical, percutaneous, or angiographic intervention should be reserved for those with significant symptoms, uncontrolled infection, bleeding and recurrence of perinephric accumulation after a conservative trial as in our case. 
| References|| |
|1.||Glassberg KI. Renal dysplasia and cystic diseases of the kidney. In: Walsh PC, Retik AB, Vaughan ED. Wein AJ (eds.). Campbell's Urology (7th ed): Philadelphia, Saunders 1998; 2: 1789. |
|2.||Papanicolaou N, Pfister RC, Yoder IC. Spontaneous and traumatic rupture of renal cysts : diagnosis and outcome. Radiology 1986: 160: 99-103. |
|3.||McLaughlin AP 111, Pfister RC. Spontaneous rupture of renal cysts into the pyelocalyceal system. J Urol 1975; 113: 2-7. |
[Figure - 1], [Figure - 2]