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Multilocular cysts of the kidney in children
T h e J o u r n a l o[ P E D I A T R I C S
249
Multilocular cysts of the kidney in children Report of a case and reviov of the literature
A case o[ a unilateral multilovular cyst o[ the kidney in a 22-month-old child is presented. Multilocular cysts o[ the kidney are rare, this case being the tenth in the pediatric age group reported in the literature. Multilocular cysts of the kidney are differentiated [rom multicystic disease, polycystic disease, and simple cyst o[ the kidney. A set of criteria [or categorizing multilocular cysts is reiterated. Some proposed theories o[ etiology o[ renal cysts are mentioned. Multilocular cysts of the kidney most commonly present as abdominal masses [ound on a routine examination and are most o#en misdiagnosed as Wilms's tumors. Hematuria is seen less frequently. The treatment is nephrectomy or simple resection where the opposite kidney is absent or insuficient.
Edward A. Dainko, M.D., Warren R. Dammers, M.D., and Steven G. Economou, M.D.* CHICAGO,
M
ILL.
u L T I L O C U L AR
cysts
of
the
kidney
are rare but specific clinical entities which must be differentiated from other abdominal masses in infants and children. I t was thought appropriate, therefore, to report an instance of such an occurrence, to discuss their management, and to present some theories on their pathogenesis.
CASE REPORT History. S. R., a female of Spanish descent, was presented at the age of 22 months to one of us ( W R D ) because of a "lump in From the Departments o[ Surgery and Pediatrics, Presbyterian-St. Luke's Hospital, Chicago 12, Illinois. *Address, 1753 West Congress Parkway, Chica~o 12, Ill.
her belly." This abdominal mass was discovered 3 days previously by the family physician in the course of a routine physical examination. There was no associated symptomatology. This was the eighth infant in this family. T h e pregnancy and delivery were uneventful. Early history and development were thought to be unremarkable by the parents except for an allergy to wool. T h e patient reportedly had an unverified case of measles 3 months prior to admission. She had 3 brothers and 5 sisters, 1 of w h o m had a history of "convulsions." T h e family history was otherwise unremarkable. N o history of renal disease was known to exist in the immediate }family or relatives.
250
Dainko, Dammers, and Economou
Fig. 1. Gross specimen. Note the normal renal configuration with the mass at the lower pole of the kidney The cystic mass does not appear too dissimilar to a solid tumor.
Fig. 2. Sectioned specimen. Note the numerous loculations of varying size within the cyst. Normal renal tissue is apparent apart from the multilocular cyst. Physical examination. T h e initial physical examination revealed a child of approximately the stated age, not acutely ill, and weighing 2 7 ~ pounds. H e r pulse was 100
August 1963
per minute and regular, the respirations 26 per minute, the rectal temperature 100.4 F., and the blood pressure 130/80 (right arm). There was some injection of the pharynx and nasal mucous membrane with moderate rhinorrhea. The significant physical findings were limited to the abdomen. Here there was a smooth firm mass approximately 3 by 3 by 8 cm. in the right upper quadrant and flank. It was seemingly nontender and moved with respiration. T h e initial impression was (1) Wilms's tumor of the right kidney and (2) resolving upper respiratory infection. Laboratory data. Blood. The hemoglobin was 10.9 Gm. per cent, the hematocrit 35 per cent, and the white blood cell count 7,200 per cubic millimeter with a normal differential. Urine. T h e specific gravity was 1.021 with a p H of 5.5; it was negative for sugar but had a trace of albumin. No red blood cells or other abnormal cells were seen in the centrifuged specimen. A plain film of the abdomen revealed a "large" area of increased density occupying the right side of the abdominal cavity and apparently separate from the liver and colon. An intravenous urogram demonstrated slight dilatation of the right renal pelvis and calyces. The left renal pelvis and calyces appeared normal. A chest x-ray and fluoroscopic studies with barium of the upper and lower intestinal tracts were interpreted to be normal. Clinical course. On the sixth hospital day, with a preoperative diagnosis of a right retroperitoneal tumor, surgery was performed. Exploration revealed a tumor involving the right kidney. The left kidney was normal to palpation and the remainder of the exploration disclosed no other abnormality. T h e right lateral peritoneum was incised and the kidney exposed. T h e entire lower pole of the kidney was replaced by a lobulated mass which felt cystic but with distinct areas of underlying firmness. I t was variably fleshypink in color. It was thought in the operating room that this was a mass of cystic and solid components. Normal renal tissue was present at the superior pole. A right he-
Volume 63 Number 2
phrectomy was performed without incident. The postoperative course was uneventful and the patient was discharged on the seventt~ postoperative day. Pathological findings. The kidney specimen weighed 120 Gin. and measured 10 cm. by 5 cm. by 4 cm. The lower half of the kidney was replaced by a multilocular noncommunicating cyst (Figs. 1 and 2) which contained clear straw-colored fluid. The variable but high tension of the fluid within some of the cysts explained the erroneous impression in the operating room of some solid component to this multilocular cyst. The kidney capsule was adherent over the cyst. Microscopically the loculi varied markedly in size and were lined by cuboidal epithelium. T h e septa were composed of cellular and fibrous tissue. Infiltration of chronic inflammatory cells was noted in some areas. In addition some smooth muscle was present. In some areas the matrix appeared looser than others (Fig. 3). Tubular and glomerular remnants were recognizable between some Ioculi immediately adjacent to the dense fibrous connective tissue capsule (Fig. 4). The grossly normal appearing renal tissue was also normal microscopically.
Multilocular cysts o[ kidney
25 1
Fig. 3. High-power photomicrograph of a portion of a septum. Note the flattened epithelium lining a cyst (upper left) and the low cuboidat epithelium of the tubules. The fibrous tissue is irregularly dense and loose.
DISCUSSION
Classification. A multilocular renal cyst is unilateral and confined to some particular part of the kidney with normal functioning renal tissue present in the remainder of the kidney. I t is to be differentiated from multicystic disease of the kidney in which no functioning renal tissue is present, but the renal parenchyma is replaced by numerous cysts held together loosely by fibrous tissue without any renal configuration. Occasionally cysts in multicystic disease of the kidney are found to communicate with the renal pelvis, unlike multilocular cysts. Multilocular cysts of the kidney differ from polycystic disease of the kidney in that in the former the septa or wall of the individual loculi are free of functioning renal tissue although occasionally an immature tubule or glomerulus m a y be present.
Fig. 4. High-power photomicrograph of a section near the periphery of the cyst showing atrophic glomeruli and tubules. An increase in fibrous tis;sue is also evident.
252
Dainko, Dammers, and Economou
August 1963
Table I. Characteristics of renal cysts
Characteristic Hereditary
Multicystic 0
Unilateral or bilateral Presence of gross renal tissue
disease
Simple cyst
Multilocular cyst
Polyeystic disease Infantile form I Adult form MendeIian Mendelian recessive dominant
0
0
Unilateral (bilateral incompatible with life)
Unilateral
Usually unilateral
Usually bilateral
Usually bilateral
0 (Hence all renal tissue is replaced)
+
+
+
+
Embryonal
Adult
Adult
Adult
Adult
0
Occasionally
Rarely
Occasionally
Occasionally
Physical sign
Abdominal mass
Abdominal mass Usually none
Usually none
Usually none
Shape of kidney
No renal configuration
Reniform
Reniform
Reniform
Reniform
Size of cysts
Wide variation
Variable, loculated
Wide variation
Small, uniform Variable
Other anomalies
Rarely
Rarely
0
Occasionally
Occasionally
0
0
Occasionally
Occasionally
Microscopic Nephrons Cartilage
Cyst communica- Occasionally tion with pelvis
No case of bilateral multilocular cysts has been reported, unlike the usually bilateral polycystic disease of the kidney. Multilocufar cysts are rarely associated with other anomalies whereas in polycystic disease of the kidney other anomalies are not unusual. T h e loculi within a multilocular renal cyst vary greatly in size whereas in polycystic disease the cysts are all approximately equal in size and are dispersed t h r o u g h o u t the substance of the kidney. Also, in multilocular renal cysts there does not seem to be any familial tendency as there is in polycystic disease of the kidney. Simple or solitary cysts of the kidney have no loculations within them and are easily differentiated grossly from multilocular cysts. Some differentiating characteristics of renal cysts are listed in Table I. Gross characteristics are depicted in Fig. 5. Since 1892, when E d m u n d s 1 first described a case of an 18-year-old girl with a multilocular cyst of the kidney, apparently only 9 patients younger than this have been described in the literature (Table I I ) . T h e
first report of ~this condition in a child was m a d e in 1940 by Burrell. 2 I n the past, terminology and classification of renal cysts has not been clear. Some of the cases included by Frazier 6 in his review fail to meet the criteria for multilocular cyst of the kidney and must be excluded. M a n y cases have been clearly multicystic disease of the kidney and others have been doubtful. Some must be excluded as they cannot be d o c u m e n t e d (e,g., A. H. Johns cited by Attwood and Grieve, 9 Lieberthal, 1~ Fey and Ferrier=). T h e latter two authors reported cases where they excised only the cyst and did not examine the remainder of the kidney. There are reports in the literature of "multilocular c y s t s " of the kidney that are now apparent multicystic disease, while others which appear to be multilocular cysts are termed " c y s t a d e n o m a " or "lymphangioma." In the F r e n c h and Italian literature multilocular cysts of the kidney are referred to as "partial polycystic kidney." Moore s employed the term "focal polycystic kidney." Powell, Shackman, and Johnson ~2
Volume 63 Number 2
Multilocular cy.~ts o[ kidney
have suggested a set of eight c r i t e r i a to be fulfilled before the condition of m u l t i l o c u l a r cyst is accepted. T h e s e were f o r m u l a t e d from their own observations a n d after reviewing the descriptions in the literature. These are: 1, T h e cyst should be u n i l a t e r a l . 2, I t should be solitary. 3, I t should be m u l t i l o c u lar. 4, T h e loculi should n o t c o m m u n i c a t e with one another. 5, I t should not c o m m u n i cate w i t h the renal pelvis. 6, T h e r e should be a definite epithelial lining to the loculi. 7, T h e residual k i d n e y tissue should be normal. 8, T h e r e should be no renal elements within the m a i n cyst. Boggs a n d K i m m e l s t i e l 7 after surveying the l i t e r a t u r e a n d r e p o r t i n g 2 cases of multilocular cysts of the k i d n e y modified the last condition b y stating "fully developed, m a t u r e n e p h r a or portions of such should not be present in the septa of the cystic lesion." This, they stated, w o u l d distinguish m u l t i l o c u l a r cysts from o t h e r congenital renal cysts a n d from polycystic disease in which portions of n o r m a l renal p a r e n c h y m a m a y be found closely intermingled w i t h the cysts. Pathogenesis. T h e etiology of these cysts is n o t k n o w n b u t there a r e several p r o posed theories. T o Boggs a n d K i m m e l s t i e l 7 "all m u l t i l o c u l a r cysts are to be r e g a r d e d as tumorous in n a t u r e r a t h e r t h a n as a result of t u b u l a r d i l a t a t i o n due to congenital obstruction of portions of n e p h r o n s . " T h u s they p r o p o s e d the t e r m "benign m u l t i l o c u l a r cystic n e p h r o m a . " C a m p b e l P s considers t h e m as aggregates of solitary cysts. Braasch a n d H e n d r i c k 14 place t h e m in the same category as simple cysts b u t agree t h a t they
253
Fig. 5. Diagrammatic presentation of gross characteristics of renal cyst. A, Multicystie; B, MultiIocular; C, Simple; D, Polycystic (infantile form) ; E, Polycystic (adult form). should have a s e p a r a t e a n d distinct classification. A r e y a~ s t a t e d t h e y are " p r o b a b l y best i n t e r p r e t e d as cystic h a m a r t o m a s . " H i l d e b r a n d t ' s 16 theory of n o n u n i o n of the collecting tubules a n d the g l o m e r u l a r secreting unit is a p o p u l a r one a n d considered by most authors as most plausible in polycystic kidney. Some authors consider n m l t i l o c u l a r cysts to be a v a r i a n t of polycystic disease. K a m p m e i e r ' s 1~ theory of a persistence of
T a b l e I I . U n i l a t e r a l m u l t i l o c u l a r cysts in children
Author 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Burrell 2 Toulson and Wagner s Chauvin 4 Carver~ FrazierG Frazier6 Boggs and KimmelstieI7 Boggs and KimmelstieI7 Moore s Present authors
I
Age 3 years 19 months 4 89 years 12 months 3 89 months 6 months 5 months 11 months 19 months 22 months
I Sex M M F F M M M M F F
I
Presentine symptom
Hematuria Abdominal mass Hematuria and abdominal mass Hematuria and abdominaI mass Abdominal mass Abdominal mass and hematuria Abdominal mass Abdominal mass Abdominal mass Abdominal mass
I Side involved Left Left Right Right Left Left Left Left Left Right
2 54
Dainko, Dammers, and Economou
an early stage of renal development is also a popular one. He showed that in the early embryo the convoluted tubules which first developed in connection with the collecting tubules are not permanent, but become detached and persist for a time as cystic structures. Later these normally regain their attachments to the collecting tubules and the cystic dilatations disappear. However, if they fail to regain reattachment they continue to grow and expand resulting in a polycystic kidney. HeplerlS, 19 was able to produce solitary cysts experimentally by fulgurating the papilla of a rabbit's one-lobed kidney and ligating the posterior branch of the renal artery. Thus, he maintains vascular insufficiency in a portion of the kidney is necessary for the production of a cyst, making its nature acquired, rather than congenitM. Clinical appearance. Whether multilocular cysts are congenital or acquired it can be said that in the beginning there are no symptoms associated with these cysts. T h e y most commonly present as an abdominal mass and are found on a routine physical examination. They are most frequently misdiagnosed as a Wilms tumor and have not yet been diagnosed correctly preoperatively. Less commonly hematuria m a y be a presenting complaint. Depending on their size and location, urinary infection or pressure symptoms on adjacent organs may be noted. Longino and Martin 2~ reported in a review of a 20 year period at the Boston children's Hospital that 32 newborn infants were found to have an abdominal mass. None of these was a multilocular cyst of the kidney. However, half of them were of renal origin. Thirteen were unilateral multicystic disease and only one was a Wilms embryoma. In all, 4 were malignant. This study would seem to support the view of an acquired nature of unilateral multilocular cyst of the kidney and emphatically shows multicystic disease to be congenital. I n order to support Hepler's theory that these cysts might result from a resolved renal infarct or hematoma of the kidney it may be necessary to assume
August 1963
that these cysts may be acquired as well as congenital. T h e main problem in recognition of a renal cyst is its differentiation from a neoplasm. Intravenous urography would be indicated as part of the evaluation. Cystoscopy and retrograde pyelography may be helpful. In some cases of multicystic disease the ureteral orifice of the involved side is absent. Renal angiography may be less fruitful because the septal blood vessel may simulate a solid tumor. However, the clouding of radiopaque material m a y not be marked as in a solid vascular tumor. Nevertheless, these would still be difficult to interpret correctly by this means in part, because of their rarity. Therapy. Since the diagnosis is at best an uncertain one, surgical exploration is indicated. Because in situ they m a y grossly resemble a malignant tumor 6 and inasmuch as any type of neoplasm or specific infection m a y occur in an abnormal kidney, 4,21 nephrectomy would be the treatment of choice. In such a case the opposite kidney must be able to support life. Simple excision of the cyst alone has been attempted when the opposite kidney was absent or defective.10, 11 SUMMARY
1. A case of a unilateral solitary multilocular cyst of the kidney in a 22-monthold child is presented. 2. Multilocular cyst of the kidney is an entity entirely separate from multicystic disease of the kidney, polycystic disease of the kidney, and simple renal cyst. 3. The etiology of multilocular cysts, as of renal cysts in general, is still unsettled. Several proposed theories are mentioned. 4. Multilocular cyst of the kidney most commonly presents as an abdominal mass found on a routine examination and is m o s t often misdiagnosed as a Wilms tumor. 5. Multilocular cysts have never been found bilaterally. 6. T r e a t m e n t is nephrectomy but where the opposite kidney is absent or insufficient, simple resection should be performed. 7. With the report of this case the num-
Volume 63 Number 2
ber of definite cases of u n i l a t e r a l multilocular cyst of the kidney in children is b r o u g h t to 10.
Mullilocular cysts of kidney
13. 14. 15.
REFERENCES
1. Edmnnds, W.: Cystic adenoma of the kidney, Tr. Path. Soc. London 43: 89, 1892. 2. Burrell, N. L.: Multilocular cysts of kidney, Report of a case, J. Urol. 43: 656, 1940. 3. Toulson, W. H., and Wagner, J. A.: Congenital encapsulated multilocular serous cyst of kidney associated with hypertension: Occurrence in a nineteen month old infant, Bull. School M. University of Maryland 26: 177, 1952. 4. Chauvin, M. E.: Un Cas de Rein Polykystique Partiel, J. d'urol. 52: 210, 1945. 5. Carver, J. H.: Cystic disease of the right kidney in an infant, Brit. J. Urol. 21: 229, 1949. 6. Frazier, T. H.: Multilocular cysts of the kidney, J. Urol. 65" 351, 1951. 7. Boggs, L. K., and Kimmelstiel, P.: Benign Multiloeular cystic nephroma: Report of two cases of so-called multilocular cyst of the kidney, J. Urol. 76" 530, 1956. 8. Moore, T.." Unilateral cystic kidneys, Brit. J. Urol. 29: 3, 1957. 9. Attwood, H. D., and Grieve, J.: Solitary multilocular cyst of the kidney, Brit. J. Urol. 30: 78, 1958. 10. Lieberthat, F.: Multilocular solitary cyst of the renal hilus, J. Urol. 42: 321, 1939. 11. Fey, B., and Ferrier, L.: Rein Polykystique Partlel, Mem. Acad. de chir. 65: 1294, 1939. 12. Powell, T., Shackman, R., and Johnson,
16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
26. 27. 28.
255
H. D.: Multilocular cysts of the kidney, Brit. J. Urol. 23: 142, 1951. Campbell, M.: Urology, Philadelphia, 1954, W. B. Saunders Company, vol. 1. Braasch, W. F., and Hendrick, J. A.: Renal cysts, simple and otherwise, J. Urol. 51: 1, 1944. Arey, J. B." Cystic lesions of the kidney in infants and children J. PEDIAT.54: 429, 1959. tlildebrandt, O.: Citedby Frazier.6 Kampmeier, O. F.: A hitherto unrecognized mode of origin of congenital renal cysts, Surg., Gynec. & Obst. 36: 208, 1923. Hepler, A. B.: Solitary cysts of the kidney, Surg., Gynec. & Obst. 50: 668, 1930. Hepler, A. B.: Etiology of multilocular cysts of the kidney, J. Urol. 44: 206, 1940. Longlno, L. A., and Martin, L. W.: Abdominal masses in the newborn infant, Pediatrics 21: 596, 1958. Ackerman, L. V.: Surgical pathology, ed. 2, St. Louis, 1959, The C. V. Mosby Company. Anderson, W. A. D.: Pathology, ed. 4, St. Louis, 1961, The C. V. Mosby Company. Boyd, W.: A textbook of pathology, ed. 7, Philadelphia, 1961, Lea & Febiger. Dakin, W. A.: Unilateral multilocular cystic kidney, Canad. M. Assoc. J. 42: 531, 1940. Randolph, M., and Murphy, F. J.: Congenital multilocular renal cyst in a newborn infant. Case report No. 105, Clin. Proc. Child. Hosp. 3: 248, 1947. True, E., Levallois, Vidal, and Pujol, Ms.: Multi-kystes Renaux au Mieux Kystes Multilocularea-du Rein. J. Urol. 64: 471, 1958. Campbell, M. F.: Pediatric urology, New York, 1937, The MacmiIlan Company, vol. 1. Wynn-Williams, D., and Morgan, A. D.: Lymphangioma of the kidney, Brit. J. Surg. 37: 346, 1949.
249
Multilocular cysts of the kidney in children Report of a case and reviov of the literature
A case o[ a unilateral multilovular cyst o[ the kidney in a 22-month-old child is presented. Multilocular cysts o[ the kidney are rare, this case being the tenth in the pediatric age group reported in the literature. Multilocular cysts of the kidney are differentiated [rom multicystic disease, polycystic disease, and simple cyst o[ the kidney. A set of criteria [or categorizing multilocular cysts is reiterated. Some proposed theories o[ etiology o[ renal cysts are mentioned. Multilocular cysts of the kidney most commonly present as abdominal masses [ound on a routine examination and are most o#en misdiagnosed as Wilms's tumors. Hematuria is seen less frequently. The treatment is nephrectomy or simple resection where the opposite kidney is absent or insuficient.
Edward A. Dainko, M.D., Warren R. Dammers, M.D., and Steven G. Economou, M.D.* CHICAGO,
M
ILL.
u L T I L O C U L AR
cysts
of
the
kidney
are rare but specific clinical entities which must be differentiated from other abdominal masses in infants and children. I t was thought appropriate, therefore, to report an instance of such an occurrence, to discuss their management, and to present some theories on their pathogenesis.
CASE REPORT History. S. R., a female of Spanish descent, was presented at the age of 22 months to one of us ( W R D ) because of a "lump in From the Departments o[ Surgery and Pediatrics, Presbyterian-St. Luke's Hospital, Chicago 12, Illinois. *Address, 1753 West Congress Parkway, Chica~o 12, Ill.
her belly." This abdominal mass was discovered 3 days previously by the family physician in the course of a routine physical examination. There was no associated symptomatology. This was the eighth infant in this family. T h e pregnancy and delivery were uneventful. Early history and development were thought to be unremarkable by the parents except for an allergy to wool. T h e patient reportedly had an unverified case of measles 3 months prior to admission. She had 3 brothers and 5 sisters, 1 of w h o m had a history of "convulsions." T h e family history was otherwise unremarkable. N o history of renal disease was known to exist in the immediate }family or relatives.
250
Dainko, Dammers, and Economou
Fig. 1. Gross specimen. Note the normal renal configuration with the mass at the lower pole of the kidney The cystic mass does not appear too dissimilar to a solid tumor.
Fig. 2. Sectioned specimen. Note the numerous loculations of varying size within the cyst. Normal renal tissue is apparent apart from the multilocular cyst. Physical examination. T h e initial physical examination revealed a child of approximately the stated age, not acutely ill, and weighing 2 7 ~ pounds. H e r pulse was 100
August 1963
per minute and regular, the respirations 26 per minute, the rectal temperature 100.4 F., and the blood pressure 130/80 (right arm). There was some injection of the pharynx and nasal mucous membrane with moderate rhinorrhea. The significant physical findings were limited to the abdomen. Here there was a smooth firm mass approximately 3 by 3 by 8 cm. in the right upper quadrant and flank. It was seemingly nontender and moved with respiration. T h e initial impression was (1) Wilms's tumor of the right kidney and (2) resolving upper respiratory infection. Laboratory data. Blood. The hemoglobin was 10.9 Gm. per cent, the hematocrit 35 per cent, and the white blood cell count 7,200 per cubic millimeter with a normal differential. Urine. T h e specific gravity was 1.021 with a p H of 5.5; it was negative for sugar but had a trace of albumin. No red blood cells or other abnormal cells were seen in the centrifuged specimen. A plain film of the abdomen revealed a "large" area of increased density occupying the right side of the abdominal cavity and apparently separate from the liver and colon. An intravenous urogram demonstrated slight dilatation of the right renal pelvis and calyces. The left renal pelvis and calyces appeared normal. A chest x-ray and fluoroscopic studies with barium of the upper and lower intestinal tracts were interpreted to be normal. Clinical course. On the sixth hospital day, with a preoperative diagnosis of a right retroperitoneal tumor, surgery was performed. Exploration revealed a tumor involving the right kidney. The left kidney was normal to palpation and the remainder of the exploration disclosed no other abnormality. T h e right lateral peritoneum was incised and the kidney exposed. T h e entire lower pole of the kidney was replaced by a lobulated mass which felt cystic but with distinct areas of underlying firmness. I t was variably fleshypink in color. It was thought in the operating room that this was a mass of cystic and solid components. Normal renal tissue was present at the superior pole. A right he-
Volume 63 Number 2
phrectomy was performed without incident. The postoperative course was uneventful and the patient was discharged on the seventt~ postoperative day. Pathological findings. The kidney specimen weighed 120 Gin. and measured 10 cm. by 5 cm. by 4 cm. The lower half of the kidney was replaced by a multilocular noncommunicating cyst (Figs. 1 and 2) which contained clear straw-colored fluid. The variable but high tension of the fluid within some of the cysts explained the erroneous impression in the operating room of some solid component to this multilocular cyst. The kidney capsule was adherent over the cyst. Microscopically the loculi varied markedly in size and were lined by cuboidal epithelium. T h e septa were composed of cellular and fibrous tissue. Infiltration of chronic inflammatory cells was noted in some areas. In addition some smooth muscle was present. In some areas the matrix appeared looser than others (Fig. 3). Tubular and glomerular remnants were recognizable between some Ioculi immediately adjacent to the dense fibrous connective tissue capsule (Fig. 4). The grossly normal appearing renal tissue was also normal microscopically.
Multilocular cysts o[ kidney
25 1
Fig. 3. High-power photomicrograph of a portion of a septum. Note the flattened epithelium lining a cyst (upper left) and the low cuboidat epithelium of the tubules. The fibrous tissue is irregularly dense and loose.
DISCUSSION
Classification. A multilocular renal cyst is unilateral and confined to some particular part of the kidney with normal functioning renal tissue present in the remainder of the kidney. I t is to be differentiated from multicystic disease of the kidney in which no functioning renal tissue is present, but the renal parenchyma is replaced by numerous cysts held together loosely by fibrous tissue without any renal configuration. Occasionally cysts in multicystic disease of the kidney are found to communicate with the renal pelvis, unlike multilocular cysts. Multilocular cysts of the kidney differ from polycystic disease of the kidney in that in the former the septa or wall of the individual loculi are free of functioning renal tissue although occasionally an immature tubule or glomerulus m a y be present.
Fig. 4. High-power photomicrograph of a section near the periphery of the cyst showing atrophic glomeruli and tubules. An increase in fibrous tis;sue is also evident.
252
Dainko, Dammers, and Economou
August 1963
Table I. Characteristics of renal cysts
Characteristic Hereditary
Multicystic 0
Unilateral or bilateral Presence of gross renal tissue
disease
Simple cyst
Multilocular cyst
Polyeystic disease Infantile form I Adult form MendeIian Mendelian recessive dominant
0
0
Unilateral (bilateral incompatible with life)
Unilateral
Usually unilateral
Usually bilateral
Usually bilateral
0 (Hence all renal tissue is replaced)
+
+
+
+
Embryonal
Adult
Adult
Adult
Adult
0
Occasionally
Rarely
Occasionally
Occasionally
Physical sign
Abdominal mass
Abdominal mass Usually none
Usually none
Usually none
Shape of kidney
No renal configuration
Reniform
Reniform
Reniform
Reniform
Size of cysts
Wide variation
Variable, loculated
Wide variation
Small, uniform Variable
Other anomalies
Rarely
Rarely
0
Occasionally
Occasionally
0
0
Occasionally
Occasionally
Microscopic Nephrons Cartilage
Cyst communica- Occasionally tion with pelvis
No case of bilateral multilocular cysts has been reported, unlike the usually bilateral polycystic disease of the kidney. Multilocufar cysts are rarely associated with other anomalies whereas in polycystic disease of the kidney other anomalies are not unusual. T h e loculi within a multilocular renal cyst vary greatly in size whereas in polycystic disease the cysts are all approximately equal in size and are dispersed t h r o u g h o u t the substance of the kidney. Also, in multilocular renal cysts there does not seem to be any familial tendency as there is in polycystic disease of the kidney. Simple or solitary cysts of the kidney have no loculations within them and are easily differentiated grossly from multilocular cysts. Some differentiating characteristics of renal cysts are listed in Table I. Gross characteristics are depicted in Fig. 5. Since 1892, when E d m u n d s 1 first described a case of an 18-year-old girl with a multilocular cyst of the kidney, apparently only 9 patients younger than this have been described in the literature (Table I I ) . T h e
first report of ~this condition in a child was m a d e in 1940 by Burrell. 2 I n the past, terminology and classification of renal cysts has not been clear. Some of the cases included by Frazier 6 in his review fail to meet the criteria for multilocular cyst of the kidney and must be excluded. M a n y cases have been clearly multicystic disease of the kidney and others have been doubtful. Some must be excluded as they cannot be d o c u m e n t e d (e,g., A. H. Johns cited by Attwood and Grieve, 9 Lieberthal, 1~ Fey and Ferrier=). T h e latter two authors reported cases where they excised only the cyst and did not examine the remainder of the kidney. There are reports in the literature of "multilocular c y s t s " of the kidney that are now apparent multicystic disease, while others which appear to be multilocular cysts are termed " c y s t a d e n o m a " or "lymphangioma." In the F r e n c h and Italian literature multilocular cysts of the kidney are referred to as "partial polycystic kidney." Moore s employed the term "focal polycystic kidney." Powell, Shackman, and Johnson ~2
Volume 63 Number 2
Multilocular cy.~ts o[ kidney
have suggested a set of eight c r i t e r i a to be fulfilled before the condition of m u l t i l o c u l a r cyst is accepted. T h e s e were f o r m u l a t e d from their own observations a n d after reviewing the descriptions in the literature. These are: 1, T h e cyst should be u n i l a t e r a l . 2, I t should be solitary. 3, I t should be m u l t i l o c u lar. 4, T h e loculi should n o t c o m m u n i c a t e with one another. 5, I t should not c o m m u n i cate w i t h the renal pelvis. 6, T h e r e should be a definite epithelial lining to the loculi. 7, T h e residual k i d n e y tissue should be normal. 8, T h e r e should be no renal elements within the m a i n cyst. Boggs a n d K i m m e l s t i e l 7 after surveying the l i t e r a t u r e a n d r e p o r t i n g 2 cases of multilocular cysts of the k i d n e y modified the last condition b y stating "fully developed, m a t u r e n e p h r a or portions of such should not be present in the septa of the cystic lesion." This, they stated, w o u l d distinguish m u l t i l o c u l a r cysts from o t h e r congenital renal cysts a n d from polycystic disease in which portions of n o r m a l renal p a r e n c h y m a m a y be found closely intermingled w i t h the cysts. Pathogenesis. T h e etiology of these cysts is n o t k n o w n b u t there a r e several p r o posed theories. T o Boggs a n d K i m m e l s t i e l 7 "all m u l t i l o c u l a r cysts are to be r e g a r d e d as tumorous in n a t u r e r a t h e r t h a n as a result of t u b u l a r d i l a t a t i o n due to congenital obstruction of portions of n e p h r o n s . " T h u s they p r o p o s e d the t e r m "benign m u l t i l o c u l a r cystic n e p h r o m a . " C a m p b e l P s considers t h e m as aggregates of solitary cysts. Braasch a n d H e n d r i c k 14 place t h e m in the same category as simple cysts b u t agree t h a t they
253
Fig. 5. Diagrammatic presentation of gross characteristics of renal cyst. A, Multicystie; B, MultiIocular; C, Simple; D, Polycystic (infantile form) ; E, Polycystic (adult form). should have a s e p a r a t e a n d distinct classification. A r e y a~ s t a t e d t h e y are " p r o b a b l y best i n t e r p r e t e d as cystic h a m a r t o m a s . " H i l d e b r a n d t ' s 16 theory of n o n u n i o n of the collecting tubules a n d the g l o m e r u l a r secreting unit is a p o p u l a r one a n d considered by most authors as most plausible in polycystic kidney. Some authors consider n m l t i l o c u l a r cysts to be a v a r i a n t of polycystic disease. K a m p m e i e r ' s 1~ theory of a persistence of
T a b l e I I . U n i l a t e r a l m u l t i l o c u l a r cysts in children
Author 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Burrell 2 Toulson and Wagner s Chauvin 4 Carver~ FrazierG Frazier6 Boggs and KimmelstieI7 Boggs and KimmelstieI7 Moore s Present authors
I
Age 3 years 19 months 4 89 years 12 months 3 89 months 6 months 5 months 11 months 19 months 22 months
I Sex M M F F M M M M F F
I
Presentine symptom
Hematuria Abdominal mass Hematuria and abdominal mass Hematuria and abdominaI mass Abdominal mass Abdominal mass and hematuria Abdominal mass Abdominal mass Abdominal mass Abdominal mass
I Side involved Left Left Right Right Left Left Left Left Left Right
2 54
Dainko, Dammers, and Economou
an early stage of renal development is also a popular one. He showed that in the early embryo the convoluted tubules which first developed in connection with the collecting tubules are not permanent, but become detached and persist for a time as cystic structures. Later these normally regain their attachments to the collecting tubules and the cystic dilatations disappear. However, if they fail to regain reattachment they continue to grow and expand resulting in a polycystic kidney. HeplerlS, 19 was able to produce solitary cysts experimentally by fulgurating the papilla of a rabbit's one-lobed kidney and ligating the posterior branch of the renal artery. Thus, he maintains vascular insufficiency in a portion of the kidney is necessary for the production of a cyst, making its nature acquired, rather than congenitM. Clinical appearance. Whether multilocular cysts are congenital or acquired it can be said that in the beginning there are no symptoms associated with these cysts. T h e y most commonly present as an abdominal mass and are found on a routine physical examination. They are most frequently misdiagnosed as a Wilms tumor and have not yet been diagnosed correctly preoperatively. Less commonly hematuria m a y be a presenting complaint. Depending on their size and location, urinary infection or pressure symptoms on adjacent organs may be noted. Longino and Martin 2~ reported in a review of a 20 year period at the Boston children's Hospital that 32 newborn infants were found to have an abdominal mass. None of these was a multilocular cyst of the kidney. However, half of them were of renal origin. Thirteen were unilateral multicystic disease and only one was a Wilms embryoma. In all, 4 were malignant. This study would seem to support the view of an acquired nature of unilateral multilocular cyst of the kidney and emphatically shows multicystic disease to be congenital. I n order to support Hepler's theory that these cysts might result from a resolved renal infarct or hematoma of the kidney it may be necessary to assume
August 1963
that these cysts may be acquired as well as congenital. T h e main problem in recognition of a renal cyst is its differentiation from a neoplasm. Intravenous urography would be indicated as part of the evaluation. Cystoscopy and retrograde pyelography may be helpful. In some cases of multicystic disease the ureteral orifice of the involved side is absent. Renal angiography may be less fruitful because the septal blood vessel may simulate a solid tumor. However, the clouding of radiopaque material m a y not be marked as in a solid vascular tumor. Nevertheless, these would still be difficult to interpret correctly by this means in part, because of their rarity. Therapy. Since the diagnosis is at best an uncertain one, surgical exploration is indicated. Because in situ they m a y grossly resemble a malignant tumor 6 and inasmuch as any type of neoplasm or specific infection m a y occur in an abnormal kidney, 4,21 nephrectomy would be the treatment of choice. In such a case the opposite kidney must be able to support life. Simple excision of the cyst alone has been attempted when the opposite kidney was absent or defective.10, 11 SUMMARY
1. A case of a unilateral solitary multilocular cyst of the kidney in a 22-monthold child is presented. 2. Multilocular cyst of the kidney is an entity entirely separate from multicystic disease of the kidney, polycystic disease of the kidney, and simple renal cyst. 3. The etiology of multilocular cysts, as of renal cysts in general, is still unsettled. Several proposed theories are mentioned. 4. Multilocular cyst of the kidney most commonly presents as an abdominal mass found on a routine examination and is m o s t often misdiagnosed as a Wilms tumor. 5. Multilocular cysts have never been found bilaterally. 6. T r e a t m e n t is nephrectomy but where the opposite kidney is absent or insufficient, simple resection should be performed. 7. With the report of this case the num-
Volume 63 Number 2
ber of definite cases of u n i l a t e r a l multilocular cyst of the kidney in children is b r o u g h t to 10.
Mullilocular cysts of kidney
13. 14. 15.
REFERENCES
1. Edmnnds, W.: Cystic adenoma of the kidney, Tr. Path. Soc. London 43: 89, 1892. 2. Burrell, N. L.: Multilocular cysts of kidney, Report of a case, J. Urol. 43: 656, 1940. 3. Toulson, W. H., and Wagner, J. A.: Congenital encapsulated multilocular serous cyst of kidney associated with hypertension: Occurrence in a nineteen month old infant, Bull. School M. University of Maryland 26: 177, 1952. 4. Chauvin, M. E.: Un Cas de Rein Polykystique Partiel, J. d'urol. 52: 210, 1945. 5. Carver, J. H.: Cystic disease of the right kidney in an infant, Brit. J. Urol. 21: 229, 1949. 6. Frazier, T. H.: Multilocular cysts of the kidney, J. Urol. 65" 351, 1951. 7. Boggs, L. K., and Kimmelstiel, P.: Benign Multiloeular cystic nephroma: Report of two cases of so-called multilocular cyst of the kidney, J. Urol. 76" 530, 1956. 8. Moore, T.." Unilateral cystic kidneys, Brit. J. Urol. 29: 3, 1957. 9. Attwood, H. D., and Grieve, J.: Solitary multilocular cyst of the kidney, Brit. J. Urol. 30: 78, 1958. 10. Lieberthat, F.: Multilocular solitary cyst of the renal hilus, J. Urol. 42: 321, 1939. 11. Fey, B., and Ferrier, L.: Rein Polykystique Partlel, Mem. Acad. de chir. 65: 1294, 1939. 12. Powell, T., Shackman, R., and Johnson,
16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
26. 27. 28.
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H. D.: Multilocular cysts of the kidney, Brit. J. Urol. 23: 142, 1951. Campbell, M.: Urology, Philadelphia, 1954, W. B. Saunders Company, vol. 1. Braasch, W. F., and Hendrick, J. A.: Renal cysts, simple and otherwise, J. Urol. 51: 1, 1944. Arey, J. B." Cystic lesions of the kidney in infants and children J. PEDIAT.54: 429, 1959. tlildebrandt, O.: Citedby Frazier.6 Kampmeier, O. F.: A hitherto unrecognized mode of origin of congenital renal cysts, Surg., Gynec. & Obst. 36: 208, 1923. Hepler, A. B.: Solitary cysts of the kidney, Surg., Gynec. & Obst. 50: 668, 1930. Hepler, A. B.: Etiology of multilocular cysts of the kidney, J. Urol. 44: 206, 1940. Longlno, L. A., and Martin, L. W.: Abdominal masses in the newborn infant, Pediatrics 21: 596, 1958. Ackerman, L. V.: Surgical pathology, ed. 2, St. Louis, 1959, The C. V. Mosby Company. Anderson, W. A. D.: Pathology, ed. 4, St. Louis, 1961, The C. V. Mosby Company. Boyd, W.: A textbook of pathology, ed. 7, Philadelphia, 1961, Lea & Febiger. Dakin, W. A.: Unilateral multilocular cystic kidney, Canad. M. Assoc. J. 42: 531, 1940. Randolph, M., and Murphy, F. J.: Congenital multilocular renal cyst in a newborn infant. Case report No. 105, Clin. Proc. Child. Hosp. 3: 248, 1947. True, E., Levallois, Vidal, and Pujol, Ms.: Multi-kystes Renaux au Mieux Kystes Multilocularea-du Rein. J. Urol. 64: 471, 1958. Campbell, M. F.: Pediatric urology, New York, 1937, The MacmiIlan Company, vol. 1. Wynn-Williams, D., and Morgan, A. D.: Lymphangioma of the kidney, Brit. J. Surg. 37: 346, 1949.