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Diverticula on distal tubule, simple renal cysts, and ureteral obstruction
DIVERTICULA
ON DISTAL TUBULE,
SIMPLE
RENAL CYSTS, AND URETERAL OBSTRUCTION Causal Relationship L. BAERT, A. STEG,
M.D. M.D.
From the Department of Anatomy, University of Leuven: Campus of Kortrijk, and the Departments of Urology, Clinic M.V., Kortrijk, Belgium, and the Cochin University Clinic, Paris, France
ABSTRACT -A case of obstruction on a localized kidney zone is reported. Obstruction was considered a precipitating factor in the morphogenesis of diverticula on the distal tubules and the simple cyst, found exclusively in the adjacent renal parenchyma to the obstruction.
In recent studies on the pathogenesis of the simple cyst in the adult, we have postulated that diverticula of the distal tubule could be precursors. l-3 The normal nephron and collecting system has no protrusions. Diverticula of the distal tubule have been found in adults, and frequency increases with age.4 All types of cyst, from microcyst (found by microdissection) to radiologically visible cyst have been found in the kidneys of elderly people without any other cystic glomerular or tubular abnormality. A certain degree of ureteral obstruction as well as weakening of tubule basal membrane, both characteristic of this age group, appear to be precipitating factors.2 The following case lends support to the hypothesis. Case Report A fifty-one-year-old female was admitted to the hospital with acute pain in the left flank and a history of lumbar pain for several months. Excretory urogram showed a partial duplication of the left urinary tract and delayed filling of dilated upper calyceal and ureteral segment (Figs. 1, 2). The remainder of the tract was normal, and the kidney outline showed a lucent renal mass in the upper pole.
UROLOGY
/ MARCH 1978 / VOLUME
XI, NUMBER 3
Ureterotomy was performed to remove a stone from the upper ureter (Figs. 1 and 2, arrow). A simple cyst of the cortex at the place of obstruction was removed after aspiration of 20 cm.3 yellow fluid. The septum separating the cyst from the calyx was opened, two other stones (Figs. 1, 2, arrows) were removed, and the septum was resutured. Biopsy of the kidney was performed from the site of obstruction. The remainder of the kidney showed a normal parenchyma without cysts; a second kidney specimen was taken on the lower kidney pole at a distance from the obstruction. There were no complications postoperatively. Histologic examination of the cyst wall showed cuboidal epithelium with otherwise normal parenchyma in the two kidney specimens. Analysis of the chemical composition of the cyst showed similar contents of simple cyst fluid (chemical features of an ultrafiltrate of plasma) (Table I). The microdissection findings from the two kidney fragments were analyzed, and the fragment from the site of obstruction was compared with the tissue taken at a distance from the obstruction. The microdissection technique used was “Darmady’s” microdissection technique. 5
221
Assessing the frequency of diverticula a count was made of those present in the nephrons and collecting tubules of the two different fragto the ments. The adjacent renal parenchyma obstruction showed severe diverticulization
FIGURE 1. Excretory urogram showing partial duplication of left urinary tract and delayed JiUing of upper segment. Stones in ureter and in upper calyx (arrows).
TABLE I. Chemical Sodium (mEq./L.) Potassium (mEq./L.) Chloride (mEq./L.) Alcahne (mEq./L.) reserve Calcium (mg./L.) Phosphorus (mg./L.) Urea (GmJL.) Creatinine (mg./L.) Uric acid (mg./L.) Protides (Gm./L.) Glucose (Gm./L.) LDH @./L.) nH
222
FIGURE 2. Delayed filling of dilated upper urinary tract segment.
Chemical composition of simple cyst fluid Number of Doses
Averages
S = Estimated Type Difference
100 99 96
150 473 118 28,7
7,8 0,5 7,2 3,l
94 95 97 58 70 94 83 87 20
72 32 0,65 11 56 21 1,13 17 8
10 5 0,23 395 16 12 0,25 21 0,5
99
UROLOGY
cyst Fluid
70 ‘0;36 11 42 29 1,lO 15 8,2
/ MARCH 1978 / VOLUME
XI, NUMBER 3
FIGURE 3. Photomicrograph of collecting and distal tubules from kidney upper-pole adjacent to calculous obstruction presenting diverticula on both. (Original magntJication X 12.5, details x 200.)
FIGURE 4. Pedunculated diverticula on distal convoluted tubules of adjacent zone to obstruction. (Original magni!cation x 12.5, details x 200.)
on the distal tubules (Figs. 3 and 4) with normal other nephron segments, whereas microdissection of the same kidney, but this time at a distance from the obstruction, showed normal nephrons and collecting tubules with mostly regular outlines (Fig. 5). Comment The possible distal tubules
UROLOGY
importance of diverticula in the morphogenesis
/ MARCH1978
on the of the
/ VOLUMEXI, NUMBER3
FIGURE 5. Mosaic photomicrograph of complete nephron at distance from place of obstruction: (1) glomerulus; (2) proximal convoluted tubule; (3) Henle’s loop; (4) distal convoluted tubule; and (5) collecting tubule.
223
simple cyst has already been underlined in previous studies. l-3 Obstruction has been considered a precipitating factor in animal6 as well as in human studies.‘,8 This observation represents a situation in which an obstruction was probably acting for a long time on a localized kidney zone (the upper part of the kidney). A simple cyst at the place of obstruction was found preoperatively. Histologic study as well as chemical analysis of the contents of the cyst showed that it was a simple cyst. Microdissection of an adjacent zone to the obstruction showed multiple diverticula on the distal convoluted tubules whereas renal biopsy at a distance from the place of obstruction showed mostly normal nephrons and collecting tubules. It appears to be acceptable to consider the distal diverticula as well as the simple cyst in this patient as secondary phenomena to the calculous obstruction, and the diverticulum would be the precursor of the simple cyst.
224
Clinique d’Urologie Universite Rene Descartes Faculte Cochin 27, Fg St Jacques - 75014 Paris, France (DR. STEG) References 1. Baert L: Les diverticules du tube contourne distal du nephron et leur signification possible en pathologie r&ale, Ann. d’Uro1. 8: 159 (1975). 2. Baert L, and Steg A: On pathogenesis of the simple renal cyst in the adults: microdissection study, Urol. Res. 5: I93 (1976). 3. IDEM: Is the diverticulum of the distal and the collecting tubules a preliminary stage of the simple cyst pathology in the adult? J, Urol. 118: 707 (1977). 4. Darmady EM, Offer J, and Woodhouse MA: The parameters of the ageing kidney, J. Pathol. 199: 195 (1972). 5. Darmady EM, and Stranack F: Microdissection of the nephron in disease, Br. Med. Bull. 13: 21 (1957). 6. Fetterman CH, Ravitch MM, and Sherman FE: Cystic changes in fetal kidneys following ureteral ligation: studies by microdissection, Kidney Int. 5: 111 (1974). 7. Baert L, and Steg A: Cystic changes in adult human kidneys after ureteral obstruction, Urologv 7: 526 (1976). 8. Steg A: Les affections kystiques du rein de l’adulte, J. d’Uro1. Nbphrol. 81 (G bis): 1 (1975).
UROLOGY
/
MARCH
1978
/
VOLUME
XI, NUMBER
3
ON DISTAL TUBULE,
SIMPLE
RENAL CYSTS, AND URETERAL OBSTRUCTION Causal Relationship L. BAERT, A. STEG,
M.D. M.D.
From the Department of Anatomy, University of Leuven: Campus of Kortrijk, and the Departments of Urology, Clinic M.V., Kortrijk, Belgium, and the Cochin University Clinic, Paris, France
ABSTRACT -A case of obstruction on a localized kidney zone is reported. Obstruction was considered a precipitating factor in the morphogenesis of diverticula on the distal tubules and the simple cyst, found exclusively in the adjacent renal parenchyma to the obstruction.
In recent studies on the pathogenesis of the simple cyst in the adult, we have postulated that diverticula of the distal tubule could be precursors. l-3 The normal nephron and collecting system has no protrusions. Diverticula of the distal tubule have been found in adults, and frequency increases with age.4 All types of cyst, from microcyst (found by microdissection) to radiologically visible cyst have been found in the kidneys of elderly people without any other cystic glomerular or tubular abnormality. A certain degree of ureteral obstruction as well as weakening of tubule basal membrane, both characteristic of this age group, appear to be precipitating factors.2 The following case lends support to the hypothesis. Case Report A fifty-one-year-old female was admitted to the hospital with acute pain in the left flank and a history of lumbar pain for several months. Excretory urogram showed a partial duplication of the left urinary tract and delayed filling of dilated upper calyceal and ureteral segment (Figs. 1, 2). The remainder of the tract was normal, and the kidney outline showed a lucent renal mass in the upper pole.
UROLOGY
/ MARCH 1978 / VOLUME
XI, NUMBER 3
Ureterotomy was performed to remove a stone from the upper ureter (Figs. 1 and 2, arrow). A simple cyst of the cortex at the place of obstruction was removed after aspiration of 20 cm.3 yellow fluid. The septum separating the cyst from the calyx was opened, two other stones (Figs. 1, 2, arrows) were removed, and the septum was resutured. Biopsy of the kidney was performed from the site of obstruction. The remainder of the kidney showed a normal parenchyma without cysts; a second kidney specimen was taken on the lower kidney pole at a distance from the obstruction. There were no complications postoperatively. Histologic examination of the cyst wall showed cuboidal epithelium with otherwise normal parenchyma in the two kidney specimens. Analysis of the chemical composition of the cyst showed similar contents of simple cyst fluid (chemical features of an ultrafiltrate of plasma) (Table I). The microdissection findings from the two kidney fragments were analyzed, and the fragment from the site of obstruction was compared with the tissue taken at a distance from the obstruction. The microdissection technique used was “Darmady’s” microdissection technique. 5
221
Assessing the frequency of diverticula a count was made of those present in the nephrons and collecting tubules of the two different fragto the ments. The adjacent renal parenchyma obstruction showed severe diverticulization
FIGURE 1. Excretory urogram showing partial duplication of left urinary tract and delayed JiUing of upper segment. Stones in ureter and in upper calyx (arrows).
TABLE I. Chemical Sodium (mEq./L.) Potassium (mEq./L.) Chloride (mEq./L.) Alcahne (mEq./L.) reserve Calcium (mg./L.) Phosphorus (mg./L.) Urea (GmJL.) Creatinine (mg./L.) Uric acid (mg./L.) Protides (Gm./L.) Glucose (Gm./L.) LDH @./L.) nH
222
FIGURE 2. Delayed filling of dilated upper urinary tract segment.
Chemical composition of simple cyst fluid Number of Doses
Averages
S = Estimated Type Difference
100 99 96
150 473 118 28,7
7,8 0,5 7,2 3,l
94 95 97 58 70 94 83 87 20
72 32 0,65 11 56 21 1,13 17 8
10 5 0,23 395 16 12 0,25 21 0,5
99
UROLOGY
cyst Fluid
70 ‘0;36 11 42 29 1,lO 15 8,2
/ MARCH 1978 / VOLUME
XI, NUMBER 3
FIGURE 3. Photomicrograph of collecting and distal tubules from kidney upper-pole adjacent to calculous obstruction presenting diverticula on both. (Original magntJication X 12.5, details x 200.)
FIGURE 4. Pedunculated diverticula on distal convoluted tubules of adjacent zone to obstruction. (Original magni!cation x 12.5, details x 200.)
on the distal tubules (Figs. 3 and 4) with normal other nephron segments, whereas microdissection of the same kidney, but this time at a distance from the obstruction, showed normal nephrons and collecting tubules with mostly regular outlines (Fig. 5). Comment The possible distal tubules
UROLOGY
importance of diverticula in the morphogenesis
/ MARCH1978
on the of the
/ VOLUMEXI, NUMBER3
FIGURE 5. Mosaic photomicrograph of complete nephron at distance from place of obstruction: (1) glomerulus; (2) proximal convoluted tubule; (3) Henle’s loop; (4) distal convoluted tubule; and (5) collecting tubule.
223
simple cyst has already been underlined in previous studies. l-3 Obstruction has been considered a precipitating factor in animal6 as well as in human studies.‘,8 This observation represents a situation in which an obstruction was probably acting for a long time on a localized kidney zone (the upper part of the kidney). A simple cyst at the place of obstruction was found preoperatively. Histologic study as well as chemical analysis of the contents of the cyst showed that it was a simple cyst. Microdissection of an adjacent zone to the obstruction showed multiple diverticula on the distal convoluted tubules whereas renal biopsy at a distance from the place of obstruction showed mostly normal nephrons and collecting tubules. It appears to be acceptable to consider the distal diverticula as well as the simple cyst in this patient as secondary phenomena to the calculous obstruction, and the diverticulum would be the precursor of the simple cyst.
224
Clinique d’Urologie Universite Rene Descartes Faculte Cochin 27, Fg St Jacques - 75014 Paris, France (DR. STEG) References 1. Baert L: Les diverticules du tube contourne distal du nephron et leur signification possible en pathologie r&ale, Ann. d’Uro1. 8: 159 (1975). 2. Baert L, and Steg A: On pathogenesis of the simple renal cyst in the adults: microdissection study, Urol. Res. 5: I93 (1976). 3. IDEM: Is the diverticulum of the distal and the collecting tubules a preliminary stage of the simple cyst pathology in the adult? J, Urol. 118: 707 (1977). 4. Darmady EM, Offer J, and Woodhouse MA: The parameters of the ageing kidney, J. Pathol. 199: 195 (1972). 5. Darmady EM, and Stranack F: Microdissection of the nephron in disease, Br. Med. Bull. 13: 21 (1957). 6. Fetterman CH, Ravitch MM, and Sherman FE: Cystic changes in fetal kidneys following ureteral ligation: studies by microdissection, Kidney Int. 5: 111 (1974). 7. Baert L, and Steg A: Cystic changes in adult human kidneys after ureteral obstruction, Urologv 7: 526 (1976). 8. Steg A: Les affections kystiques du rein de l’adulte, J. d’Uro1. Nbphrol. 81 (G bis): 1 (1975).
UROLOGY
/
MARCH
1978
/
VOLUME
XI, NUMBER
3