THE JOURNAL OF UROLOGY
Vol. 113, ,January
Copyright © 1975 by The Williams & Wilkins Co.
Printed in U.S.A.
SPONTANEOUS RUPTURE OF RENAL CYSTS INTO THE PYELOCALICEAL SYSTEM A. P. MCLAUGHLIN, Ill* AND R. C. PFISTER
From the Division of Urology, Department of Surgery, University Hospital, University of California School of Medicine, San Diego, California, and the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
transfusions. In the 2 patients with upper urinary tract infections, fever and flank discomfort preceded the onset of hematuria from 6 to 14 days. All 4 patients with spontaneous rupture of simple cysts had 2 or more cysts of variable size in the involved kidney. Five patients had been studied previously by IVP or nephrotomography with documentation of pre-existing renal cystic disease. Surgical or histochemical verification of the radiologic diagnosis of spontaneous cyst rupture was obtained in 2 patients. Kidney exploration in case 1 demonstrated an infected cyst which was marsupialized. Percutaneous cyst aspiration in case 2 produced brown fluid. Cytologic ex8mination of the aspirate and Sudan IV stains for lipid was negative.
There have been only sporadic reports on the trauma tic 1 or spontaneous rupture 2 of renal cysts into the pyelocaliceal system. The clinical and radiologic features of spontaneous renal cyst rupture with direct pyelocaliceal communication in 6 patients are described herein. Although this entity has been reported upon infrequently, non-traumatic, spontaneous cyst rupture in our clinical material occurred in 1 of every 4,000 excretory urograms (IVPs). In these cases uroradiologic studies demonstrated backflow of contrast medium from the pyelocaliceal system into the ruptured cystic cavity. This uncommon radiologic phenomenon may lead to diagnostic confusion in patients who present with gross hematuria. Appreciation of the pyelographic findings and the predisposing clinical events that may lead to spontaneous cyst rupture are important in making the correct differential diagnosis.
RADIOLOGY At,;D ANATOMY
IVP demonstrated the abnormal communication between the pyelocaliceal system and the cystic cavity. In patients with polycystic renal disease, infection or reduced renal function. high dose
CASE MATERIAL
Clinical information for this group of cases is presented in the table. All patients had gross
Case material Case
Pt.
No. - Age -Sex
Presenting Symptoms
1-79-M
Fever. flank pain, gross hematuria Acute flank pain, gross hematuria Painless hematuria Acute flank pain, gross hematuria Acute abdominal pain. gross hematuria Fever, flank pain, gross hematuria
2-61-M 3-65-M 4-26-F 5-45-M 6-53-F
Predisposing Factors
Urographic Diagnosis
Urinary Tract Infection
Simple cyst
Hypertension
Other
Klebsiella (upper tract)
Simple cyst
-
+
Simple cyst Simple cyst
-
-
E. coli (lower tract)
-
-
4
Polycystic kidney Polycvstic kidney
hematuria usually associated with flank or abdominal pain. The gross bleeding stopped spontaneously within 24 to 48 hours except in cases :3 and 6, in which there was prolonged hematuria requiring
Pseudomonas ( upper tract)
-
Coumadin therapy
Congenital factor VIII deficiency
urography may be required for adequate visualization of the renal collecting system. Since the ruptured cyst cavity fills in retrograde fashion from the pyelocaliceal communication, delayed films will optimally show progressive opacification of the cystic space. Nephrotomography is most helpful in clearly outlining the details of the opacified cystic space and should be performed in each case to assure accurate diagnosis. Examination of the patients in the prone position may improve cyst visualization. Abdominal compression can be occasionally helpful and was used in 1 patient. In our series the ruptured cysts were in the upper pole in :3
Accepted for publication June 21, 1974. Read at annual meeting of American Urological Association, St. Louis, Missouri, May 19-23, 1974. * Requests for reprints: Division of Urology, University Hospital, San Diego, California 92103. 1 Reiss, M. D.: Traumatic rupture of renal cortical cyst into the calyceal system. Amer. J. Roentgen .. 101: 696, 1967. 2 Y den, S.: Cyst rupture in 6 cases of polycystic renal disease. Acta. Radio!., 42: 17, 1954. 2
3
SPONTANEOUS RUPTURE OF RENAL CYSTS
COMMUNICATING CYST
CALYCEAL DIVERTICULUM
•;c__._,.~......,:--- Lobular margin Corlico Medu//ory Junction
,.....____,,,--5moolli, I/Jin wolf 1t•F--=,--Ft//ing defects (blood)
.,-,..--1.-,r~~, Wide
communication
RENAL TUMOR or CARBUNCLE Colyceo/ distortion T/Jick Ft/ling defects ( necrotic debris or blood)
FIG. 1. Differential diagnosis of renal masses filling with contrast medium from pyelocaliceal backflow includes communicating renal cysts, caliceal diverticula, renal tumors and carbuncles. Uroradiologic features of each entity are usually well delineated by nephrotomography.
patients, the lower pole in 2 and in the mid portion of the kidney in the other case. The cystic cavity is usually subcapsular and abuts directly against the renal pelvis or calix. In this group of patients the average diameter of the ruptured cyst was 3 cm. These features help to differentiate this entity from pyelocaliceal diverticula which are corticomedullary in location and have elongated, narrow necks. 3 During urographic evaluation the cyst appears to have a smooth or lobular inner wall, depending on the degree of cystic distension with contrast material. Filling defects within the lumen of the cyst may be blood clots or infected debris. When these non-opaque defects are surrounded by a rough, thickened wall with poorly defined, irregular pooling of contrast material, necrotic tumor• or a renal cortical abscess must be excluded (fig. 1). Erosion of a renal hydatid cyst into a primary calix is a rare event in our population and can be excluded by urinalysis. 5 Interestingly, the acute tear in the cyst wall appears to close rapidly if there is no persistent hemorrhage or increased pressure in the renal pelvis from pyeloureteral obstruction. In 3 patients who had subsequent IVPs within 24 to 72 hours following acute rupture, no communication or cyst opacification was demonstrated. This finding was confirmed in 1 case reported by Yden in his series of polycystic kidneys. 2 Detailed examples of these uroradiologic findings are presented in figures 2 to 5. 3 Middleton, A. W., Jr. and Pfister, R. C.: Stone-containing pyelocaliceal diverticulum: Embryogenic, anatomic, radiologic and clinical characteristics. J. Urol., 111: 2, 1974. 'Kyaw, M. M.: Pyelotumor backflow. A manifestation of renal cell carcinoma. Clin. Radio!.. 24: 459, 1973. 'Roylance, J., Davies, E. R. and Alexander, W. D.: Translumbar puncture of a renal hydatid cyst. Brit. J. Radio!., 46: 960, 1973.
Histologic examination of the membrane lining the cyst wall commonly demonstrates a flattened cuboidal epithelium along with patchy fibrosis in the area of rupture. 6 The presence of cuboidal epithelium differentiates these cysts from the caliceal diverticulum or pyelogenic cyst which are lined by transitional epithelium. At the time of surgical exploration the lining of an infected cyst may show a thick, fibrous wall with nodular irregularities grossly suggestive of neoplasm. DISCUSSION
Pathogenesis. The pathogenesis of ruptured renal cysts is unclear except when it has occurred following blunt renal trauma, which produces an acute rise in intracystic pressure,6 or when the cyst has become infected (fig. 6). The inflammatory changes associated with bacterial infection may weaken the common dividing wall between the cyst and the pyelocaliceal system as well as producing a rise in intracystic pressure resulting in cyst rupture. This mechanism could have been active in our 2 patients with upper tract bacteriuria. In the absence of trauma and infection spontaneous rupture of a renal cyst with subsequent communication with the pyelocaliceal system should be caused by either rising intrapyelocaliceal pressure or rising intracystic pressure. No patient in this group had definite clinical or radiologic evidence of increased intrapyelocaliceal pressure which may occur with ureteral calculi, neurogenic bladder disease or prostatic obstruction. Interestingly, intracystic pressures are variable, ranging from 6 to 15 cm. water which may be higher than 6 Pfister, R. C., McLaughlin, A. P., Talner, L. B., Gittes, R. F. and Mellins, H. Z.: Traumatic rupture of renal cortical cyst into the pyelocalyceal system. Amer. J. Roentgen., in press, 1974.
4
MCLAUGHLIN AND PFISTER
FIG. 2. Case 1. A, nephrotomogram demonstrates bilateral simple renal cysts at time of elective prostatectomy. Arrowheads outline inferior margin of large right lower pole cyst. B, IVP 3 months later when patient presented with fever, flank pain and gross hematuria. Detailed view at 90 minutes shows early opacification of right lower pole cyst with wide caliceal communication. Note lobular inner cyst wall (arrow) and filling defects within cavity which was infected. C, retrograde ureterogram outlines blood clot which was partially obstructing ureteropelvic junction.
normal intrapelvic pressure. 7 Idiopathic alteration in the dynamics of the cyst fluid could increase the intracystic pressure. with subsequent expansion, thereby producing atrophy of the cyst wall. Tearing of this wall with laceration of local blood vessels could result in pyelocaliceal communication and gross hematuria as seen in case 4, in which there were no other obvious, predisposing factors. Alternatively, intracystic hemorrhage may be the initial event which produces acute cyst expansion with tearing of the dividing walls between the cyst and the pyelocaliceal system. Hypertension present in cases 2 and 5 could initiate sudden bleeding from the thin attenuated vessels lining the cyst wall. Initial intracystic hemorrhage producing increased pressure and cyst rupture could also result from iatrogenic or congenital clotting deficiencies (cases 3 and 6). 7
Pfister, R. C.: Personal communication.
Management. In patients with previously documented renal cystic disease, who present with the typical clinical and uroradiologic features of spontaneous cyst rupture, further diagnostic studies may not be necessary, providing these lesions have remained radiologically stable. Conservative medical management, including antibiotics in patients with urinary tract infection, is often sufficient treatment, since closure of the torn wall usually occurs within 3 days with cessation of bleeding. This is documented in our series of patients who have been followed from 2 months to 4 years. When the diagnosis remains unclear we prefer to perform percutaneous renal puncture followed by air-contrast study of the mass to rule out the coexistence of cyst and renal tumor in the same kidney, which has a reported incidence of 2 per cent.8 The 8 Brannan, W., Miller, W. and Crisler, M.: Coexistence of renal neoplasms and renal cysts. South. Med. J .., 55: 749, 1962.
SPONTANEOUS RUPTURE OF RENAL CYSTS
FIG. 3. Case 2. A, nephrotomogram of right kidney performed during hypertensive evaluation revealed 17 cm. lower pole cyst (arrows), as well as peripelvic and outer cortical cysts. B, IVP shows contraction of lower pole cyst following percutaneous aspiration and pantopaque instillation. C. IVP 18 months later when patient returned still hypertensive with gross hematuria demonstrates opacification of peripelvic cavity. Retrograde pyelograms suggested that cyst communicated directly with renal pelvis.
FIG. 4. Case 3. A, IVP shows 2 upper pole masses with microscopic hematuria while on coumadin therapy. B, nephrotomogram of right kidney suggests that these lesions are simple cysts. C, nephrotomogram 5 years later reveals opacification of 1 cyst with direct caliceal communication. This patient was still taking coumadin and presented with gross, painless hematuria.
possibility of aspirating tumor cells should not be a contraindication to renal puncture, since there is n? evidence for either:im plantationof tumor cells or vascular dissemination when tumors are needled. 9 •Von Schreeb, T., Arner, 0., Skovsted, G. and Wik-
Cytologic or histologic abnormalities in the rate along with irregular defects in the cyst stad, N.: Renal adenocarcinoma. Is there a risk of spreading tumour cells in diagnostic puncture? Scand. ,J. Urol. Nephrol., l: 270, 1967.
6
MCLAUGHLIN AND PFISTER
FIG. 5. Case 4. A, IVP shows retrograde filling of smooth, lower pole cyst through apparent communication with renal pelvis. B, IVP 24 hours later fails to demonstrate cyst opacification because of rapid closure of this communication. Concave impression on renal pelvis persists (arrow).
PATHOGENESIS OF CYST BREAKDOWN ~~~E_[)
~CYST
F~UI~ ~Y_N_A~I~
l® ©
. . - - - - - - - - - - , ~ Elevated 1ntracyst1c pressure
:HYPERTE~
tI
@
~
~R;M~
~~ECT~
/ssure atro~
Vessel wall
Cyst wall
t
+
Tear
---------lntracystic hemorrhage PERI RENAL
RUPTURE
EXTRARENAL LEAKAGE
AND HEMATOMA
~::::::~ INTERNAL COMMUNICATION TO PYELOCALYCEAL SYSTEM GROSS HEMATURIA
FIG. 6. Probable mechanisms resulting in rupture of renal cortical cysts into pyelocaliceal system. Spontaneous intracystic hemorrhage from clotting deficiencies may also produce these clinical and uroradiologic findings. Traur:rn can result in concurrent internal communication with collecting system and extrarenal extravasation.
underline the need for subsequent angiography and/or an operation. Infected renal cysts may give falsely positive histochemical and cystographic results 10 but must be further evaluated to avoid the tragic error of misdiagnosing a renal tumor as a benign cyst. Ultrasound scanning of ruptured renal cortical cysts has limited usefulness, since some cystic 10 Lang, E. K.: Coexistence of cyst and tumor in the same kidney. Radiology, 101: 7, 1971.
cavities contain infected debris or blood clot and would, therefore, appear as complex masses on the sonogram. Because renal cysts are by definition sonolucent, 11 the findings of echoes within the ruptured cyst could be misleading and result in an unnecessary operation, if the clinician places 11 McLaughlin, A. P., III, Talner, L.B., Leopold, G. R. and McCullough, D. L.: Avascular primary renal cell carcinoma: varied pathologic and angiographic features. J. Urol., 111: 587, 1974.
SPONTANEOUS RUPTURE OF RENAL CYSTS
undue reliance on ultrasound diagnosis. Retrograde ureteral catheterization may be of value in certain situations to obtain urine from the affected kidney for urine cytology and culture or to visualize and temporarily bypass an obstructed ureter. Surgical exploration of spontaneously ruptured cysts might be indicated to marsupialize an infected cyst which has subsequently sealed off or in cases of persistent renal bleeding. Although no patient in this series experienced cyst rupture following pyeloureteral obstruction, such cases often will require urologic intervention. SUMMARY
Patients with spontaneous rupture of renal cortical cysts into the pyelocaliceal system present with
7
gross hematuria, usually associated with flank or abdominal pain. Diagnosis is established by retrograde filling of the cyst cavity with contrast material through a wide pyelocaliceal communication visualized during IVP with nephrotomography. Percutaneous renal puncture with histochemical analysis of the aspirate is indicated in certain patients for diagnostic confirmation. Renal angiography and/or an operation should be performed when the differential diagnosis remains unclear. Antibiotics in the patients with urinary tract infections along with conservative medical management is sufficient treatment, since rapid closure of the cyst-pyelocaliceal communication with cessation of hemorrhage occurs rapidly in most patients.
Vol. 113, ,January
Copyright © 1975 by The Williams & Wilkins Co.
Printed in U.S.A.
SPONTANEOUS RUPTURE OF RENAL CYSTS INTO THE PYELOCALICEAL SYSTEM A. P. MCLAUGHLIN, Ill* AND R. C. PFISTER
From the Division of Urology, Department of Surgery, University Hospital, University of California School of Medicine, San Diego, California, and the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
transfusions. In the 2 patients with upper urinary tract infections, fever and flank discomfort preceded the onset of hematuria from 6 to 14 days. All 4 patients with spontaneous rupture of simple cysts had 2 or more cysts of variable size in the involved kidney. Five patients had been studied previously by IVP or nephrotomography with documentation of pre-existing renal cystic disease. Surgical or histochemical verification of the radiologic diagnosis of spontaneous cyst rupture was obtained in 2 patients. Kidney exploration in case 1 demonstrated an infected cyst which was marsupialized. Percutaneous cyst aspiration in case 2 produced brown fluid. Cytologic ex8mination of the aspirate and Sudan IV stains for lipid was negative.
There have been only sporadic reports on the trauma tic 1 or spontaneous rupture 2 of renal cysts into the pyelocaliceal system. The clinical and radiologic features of spontaneous renal cyst rupture with direct pyelocaliceal communication in 6 patients are described herein. Although this entity has been reported upon infrequently, non-traumatic, spontaneous cyst rupture in our clinical material occurred in 1 of every 4,000 excretory urograms (IVPs). In these cases uroradiologic studies demonstrated backflow of contrast medium from the pyelocaliceal system into the ruptured cystic cavity. This uncommon radiologic phenomenon may lead to diagnostic confusion in patients who present with gross hematuria. Appreciation of the pyelographic findings and the predisposing clinical events that may lead to spontaneous cyst rupture are important in making the correct differential diagnosis.
RADIOLOGY At,;D ANATOMY
IVP demonstrated the abnormal communication between the pyelocaliceal system and the cystic cavity. In patients with polycystic renal disease, infection or reduced renal function. high dose
CASE MATERIAL
Clinical information for this group of cases is presented in the table. All patients had gross
Case material Case
Pt.
No. - Age -Sex
Presenting Symptoms
1-79-M
Fever. flank pain, gross hematuria Acute flank pain, gross hematuria Painless hematuria Acute flank pain, gross hematuria Acute abdominal pain. gross hematuria Fever, flank pain, gross hematuria
2-61-M 3-65-M 4-26-F 5-45-M 6-53-F
Predisposing Factors
Urographic Diagnosis
Urinary Tract Infection
Simple cyst
Hypertension
Other
Klebsiella (upper tract)
Simple cyst
-
+
Simple cyst Simple cyst
-
-
E. coli (lower tract)
-
-
4
Polycystic kidney Polycvstic kidney
hematuria usually associated with flank or abdominal pain. The gross bleeding stopped spontaneously within 24 to 48 hours except in cases :3 and 6, in which there was prolonged hematuria requiring
Pseudomonas ( upper tract)
-
Coumadin therapy
Congenital factor VIII deficiency
urography may be required for adequate visualization of the renal collecting system. Since the ruptured cyst cavity fills in retrograde fashion from the pyelocaliceal communication, delayed films will optimally show progressive opacification of the cystic space. Nephrotomography is most helpful in clearly outlining the details of the opacified cystic space and should be performed in each case to assure accurate diagnosis. Examination of the patients in the prone position may improve cyst visualization. Abdominal compression can be occasionally helpful and was used in 1 patient. In our series the ruptured cysts were in the upper pole in :3
Accepted for publication June 21, 1974. Read at annual meeting of American Urological Association, St. Louis, Missouri, May 19-23, 1974. * Requests for reprints: Division of Urology, University Hospital, San Diego, California 92103. 1 Reiss, M. D.: Traumatic rupture of renal cortical cyst into the calyceal system. Amer. J. Roentgen .. 101: 696, 1967. 2 Y den, S.: Cyst rupture in 6 cases of polycystic renal disease. Acta. Radio!., 42: 17, 1954. 2
3
SPONTANEOUS RUPTURE OF RENAL CYSTS
COMMUNICATING CYST
CALYCEAL DIVERTICULUM
•;c__._,.~......,:--- Lobular margin Corlico Medu//ory Junction
,.....____,,,--5moolli, I/Jin wolf 1t•F--=,--Ft//ing defects (blood)
.,-,..--1.-,r~~, Wide
communication
RENAL TUMOR or CARBUNCLE Colyceo/ distortion T/Jick Ft/ling defects ( necrotic debris or blood)
FIG. 1. Differential diagnosis of renal masses filling with contrast medium from pyelocaliceal backflow includes communicating renal cysts, caliceal diverticula, renal tumors and carbuncles. Uroradiologic features of each entity are usually well delineated by nephrotomography.
patients, the lower pole in 2 and in the mid portion of the kidney in the other case. The cystic cavity is usually subcapsular and abuts directly against the renal pelvis or calix. In this group of patients the average diameter of the ruptured cyst was 3 cm. These features help to differentiate this entity from pyelocaliceal diverticula which are corticomedullary in location and have elongated, narrow necks. 3 During urographic evaluation the cyst appears to have a smooth or lobular inner wall, depending on the degree of cystic distension with contrast material. Filling defects within the lumen of the cyst may be blood clots or infected debris. When these non-opaque defects are surrounded by a rough, thickened wall with poorly defined, irregular pooling of contrast material, necrotic tumor• or a renal cortical abscess must be excluded (fig. 1). Erosion of a renal hydatid cyst into a primary calix is a rare event in our population and can be excluded by urinalysis. 5 Interestingly, the acute tear in the cyst wall appears to close rapidly if there is no persistent hemorrhage or increased pressure in the renal pelvis from pyeloureteral obstruction. In 3 patients who had subsequent IVPs within 24 to 72 hours following acute rupture, no communication or cyst opacification was demonstrated. This finding was confirmed in 1 case reported by Yden in his series of polycystic kidneys. 2 Detailed examples of these uroradiologic findings are presented in figures 2 to 5. 3 Middleton, A. W., Jr. and Pfister, R. C.: Stone-containing pyelocaliceal diverticulum: Embryogenic, anatomic, radiologic and clinical characteristics. J. Urol., 111: 2, 1974. 'Kyaw, M. M.: Pyelotumor backflow. A manifestation of renal cell carcinoma. Clin. Radio!.. 24: 459, 1973. 'Roylance, J., Davies, E. R. and Alexander, W. D.: Translumbar puncture of a renal hydatid cyst. Brit. J. Radio!., 46: 960, 1973.
Histologic examination of the membrane lining the cyst wall commonly demonstrates a flattened cuboidal epithelium along with patchy fibrosis in the area of rupture. 6 The presence of cuboidal epithelium differentiates these cysts from the caliceal diverticulum or pyelogenic cyst which are lined by transitional epithelium. At the time of surgical exploration the lining of an infected cyst may show a thick, fibrous wall with nodular irregularities grossly suggestive of neoplasm. DISCUSSION
Pathogenesis. The pathogenesis of ruptured renal cysts is unclear except when it has occurred following blunt renal trauma, which produces an acute rise in intracystic pressure,6 or when the cyst has become infected (fig. 6). The inflammatory changes associated with bacterial infection may weaken the common dividing wall between the cyst and the pyelocaliceal system as well as producing a rise in intracystic pressure resulting in cyst rupture. This mechanism could have been active in our 2 patients with upper tract bacteriuria. In the absence of trauma and infection spontaneous rupture of a renal cyst with subsequent communication with the pyelocaliceal system should be caused by either rising intrapyelocaliceal pressure or rising intracystic pressure. No patient in this group had definite clinical or radiologic evidence of increased intrapyelocaliceal pressure which may occur with ureteral calculi, neurogenic bladder disease or prostatic obstruction. Interestingly, intracystic pressures are variable, ranging from 6 to 15 cm. water which may be higher than 6 Pfister, R. C., McLaughlin, A. P., Talner, L. B., Gittes, R. F. and Mellins, H. Z.: Traumatic rupture of renal cortical cyst into the pyelocalyceal system. Amer. J. Roentgen., in press, 1974.
4
MCLAUGHLIN AND PFISTER
FIG. 2. Case 1. A, nephrotomogram demonstrates bilateral simple renal cysts at time of elective prostatectomy. Arrowheads outline inferior margin of large right lower pole cyst. B, IVP 3 months later when patient presented with fever, flank pain and gross hematuria. Detailed view at 90 minutes shows early opacification of right lower pole cyst with wide caliceal communication. Note lobular inner cyst wall (arrow) and filling defects within cavity which was infected. C, retrograde ureterogram outlines blood clot which was partially obstructing ureteropelvic junction.
normal intrapelvic pressure. 7 Idiopathic alteration in the dynamics of the cyst fluid could increase the intracystic pressure. with subsequent expansion, thereby producing atrophy of the cyst wall. Tearing of this wall with laceration of local blood vessels could result in pyelocaliceal communication and gross hematuria as seen in case 4, in which there were no other obvious, predisposing factors. Alternatively, intracystic hemorrhage may be the initial event which produces acute cyst expansion with tearing of the dividing walls between the cyst and the pyelocaliceal system. Hypertension present in cases 2 and 5 could initiate sudden bleeding from the thin attenuated vessels lining the cyst wall. Initial intracystic hemorrhage producing increased pressure and cyst rupture could also result from iatrogenic or congenital clotting deficiencies (cases 3 and 6). 7
Pfister, R. C.: Personal communication.
Management. In patients with previously documented renal cystic disease, who present with the typical clinical and uroradiologic features of spontaneous cyst rupture, further diagnostic studies may not be necessary, providing these lesions have remained radiologically stable. Conservative medical management, including antibiotics in patients with urinary tract infection, is often sufficient treatment, since closure of the torn wall usually occurs within 3 days with cessation of bleeding. This is documented in our series of patients who have been followed from 2 months to 4 years. When the diagnosis remains unclear we prefer to perform percutaneous renal puncture followed by air-contrast study of the mass to rule out the coexistence of cyst and renal tumor in the same kidney, which has a reported incidence of 2 per cent.8 The 8 Brannan, W., Miller, W. and Crisler, M.: Coexistence of renal neoplasms and renal cysts. South. Med. J .., 55: 749, 1962.
SPONTANEOUS RUPTURE OF RENAL CYSTS
FIG. 3. Case 2. A, nephrotomogram of right kidney performed during hypertensive evaluation revealed 17 cm. lower pole cyst (arrows), as well as peripelvic and outer cortical cysts. B, IVP shows contraction of lower pole cyst following percutaneous aspiration and pantopaque instillation. C. IVP 18 months later when patient returned still hypertensive with gross hematuria demonstrates opacification of peripelvic cavity. Retrograde pyelograms suggested that cyst communicated directly with renal pelvis.
FIG. 4. Case 3. A, IVP shows 2 upper pole masses with microscopic hematuria while on coumadin therapy. B, nephrotomogram of right kidney suggests that these lesions are simple cysts. C, nephrotomogram 5 years later reveals opacification of 1 cyst with direct caliceal communication. This patient was still taking coumadin and presented with gross, painless hematuria.
possibility of aspirating tumor cells should not be a contraindication to renal puncture, since there is n? evidence for either:im plantationof tumor cells or vascular dissemination when tumors are needled. 9 •Von Schreeb, T., Arner, 0., Skovsted, G. and Wik-
Cytologic or histologic abnormalities in the rate along with irregular defects in the cyst stad, N.: Renal adenocarcinoma. Is there a risk of spreading tumour cells in diagnostic puncture? Scand. ,J. Urol. Nephrol., l: 270, 1967.
6
MCLAUGHLIN AND PFISTER
FIG. 5. Case 4. A, IVP shows retrograde filling of smooth, lower pole cyst through apparent communication with renal pelvis. B, IVP 24 hours later fails to demonstrate cyst opacification because of rapid closure of this communication. Concave impression on renal pelvis persists (arrow).
PATHOGENESIS OF CYST BREAKDOWN ~~~E_[)
~CYST
F~UI~ ~Y_N_A~I~
l® ©
. . - - - - - - - - - - , ~ Elevated 1ntracyst1c pressure
:HYPERTE~
tI
@
~
~R;M~
~~ECT~
/ssure atro~
Vessel wall
Cyst wall
t
+
Tear
---------lntracystic hemorrhage PERI RENAL
RUPTURE
EXTRARENAL LEAKAGE
AND HEMATOMA
~::::::~ INTERNAL COMMUNICATION TO PYELOCALYCEAL SYSTEM GROSS HEMATURIA
FIG. 6. Probable mechanisms resulting in rupture of renal cortical cysts into pyelocaliceal system. Spontaneous intracystic hemorrhage from clotting deficiencies may also produce these clinical and uroradiologic findings. Traur:rn can result in concurrent internal communication with collecting system and extrarenal extravasation.
underline the need for subsequent angiography and/or an operation. Infected renal cysts may give falsely positive histochemical and cystographic results 10 but must be further evaluated to avoid the tragic error of misdiagnosing a renal tumor as a benign cyst. Ultrasound scanning of ruptured renal cortical cysts has limited usefulness, since some cystic 10 Lang, E. K.: Coexistence of cyst and tumor in the same kidney. Radiology, 101: 7, 1971.
cavities contain infected debris or blood clot and would, therefore, appear as complex masses on the sonogram. Because renal cysts are by definition sonolucent, 11 the findings of echoes within the ruptured cyst could be misleading and result in an unnecessary operation, if the clinician places 11 McLaughlin, A. P., III, Talner, L.B., Leopold, G. R. and McCullough, D. L.: Avascular primary renal cell carcinoma: varied pathologic and angiographic features. J. Urol., 111: 587, 1974.
SPONTANEOUS RUPTURE OF RENAL CYSTS
undue reliance on ultrasound diagnosis. Retrograde ureteral catheterization may be of value in certain situations to obtain urine from the affected kidney for urine cytology and culture or to visualize and temporarily bypass an obstructed ureter. Surgical exploration of spontaneously ruptured cysts might be indicated to marsupialize an infected cyst which has subsequently sealed off or in cases of persistent renal bleeding. Although no patient in this series experienced cyst rupture following pyeloureteral obstruction, such cases often will require urologic intervention. SUMMARY
Patients with spontaneous rupture of renal cortical cysts into the pyelocaliceal system present with
7
gross hematuria, usually associated with flank or abdominal pain. Diagnosis is established by retrograde filling of the cyst cavity with contrast material through a wide pyelocaliceal communication visualized during IVP with nephrotomography. Percutaneous renal puncture with histochemical analysis of the aspirate is indicated in certain patients for diagnostic confirmation. Renal angiography and/or an operation should be performed when the differential diagnosis remains unclear. Antibiotics in the patients with urinary tract infections along with conservative medical management is sufficient treatment, since rapid closure of the cyst-pyelocaliceal communication with cessation of hemorrhage occurs rapidly in most patients.
