Vol. 117, June Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
MATRIX STONES TAKUO KOIDE, MITSUO MIYAGAWA
AND
KATSUHIRO KINOSHITA
From the Ashiya City Hospital, Hyogo and the Department of Urology, Osaka University, Fukushima, Osaka, Japan
ABSTRACT
A scanning electron microscopic examination of matrix stones, which have been obtained from a 27-month-old Japanese boy with congenital hydronephrosis, revealed a rough fibrous net structure with small depositions of calcium phosphate. We believe that fibrous matrix may be the primary constituent and that the matrix stone may be the consequence of calcium deposition to it. Matrix stones, first described in 1908 as fibrous stones, 1 are yellowish-white to light tan in color and have a soft putty-like structure without any demonstrable nucleus. In ordinary crystalline stones the matrix accounts for 2.5 per cent of the dry weight but in matrix stones the comparable average is 65 per cent of the dry weight. 2 These stones may be entirely radiolucent or may contain faintly stippled calcification, which can be
CASE REPORT
A 27-month-old Japanese boy had left flank pain, fever and pyuria. Urine culture yielded Proteus .. A plain x-ray showed partially calcified shadows in the left kidney and an excretory urogram revealed left hydronephrosis owing to pelvioureteral junction stenosis.
Scanning electron microscopic examination on section through center of matrix stones reveals rough fibrous net structure with small depositions of calcium phosphate, which is covered thinly with magnesium ammonium phosphate. A, reduced from x 1,000. B and C, reduced from x3,000.
identified on a plain film. The vast literature on the derivation of urinary calculi recognizes and refers briefly to this rare type of calculus. Herein we present a reliable spectrum concerning matrix stone formation from scanning electron microscopy. Accepted for publication December 30, 1976. 786
Laboratory data included serum calcium 9.2, serum phosphate 4.4 mg. per 100 ml. and 24-hour urinary calcium excretion 22 mg. Pyelolithotomy and pyeloplasty were performed and 12 putty-like soft stones were removed. Postoperatively, the left hydronephrosis improved but urinary infection continued. Four months later a faintly stippled
787 calcified shado•u recurrence of a
vvh~ch
ths
the derivation of matrix stones low calcium content. matrix stones occur in the presence of urinary infection, especially by Proteus. 3 • 6-ll In our patient the Proteus infection had been indicated before and after the improvement of urinary stasis operation and a stone had recurred under this circumstance. Williams reported a similar case in which matrix stones recurred in an infected child after the elimination of urinary stasis. 8 These clinical courses suggest strongly the close relationship between urinary infection and matrix stone formation. The reason massive calcification does not occur in matrix stones has not been explained clearly. Diminished 24-hour urinary calcium excretion, often occurring in matrix stone formers, has been noted frequently. 2·" This low urinary calcium excretion might be related to the poor calcification of this type of stone. Although the 24-hour urinary calcium excretion was within the normal range in our patient a unilateral decrease in calcium excretion could be masked by a healthy opposite kidney." From these discussions and scanning electron microscopic findings we suggest a more reliable spectrum concerning the derivation of matrix stones. Some local conditions within the kidney, for example infection, injury or ·another disorder, cause the primary precipitation of the fibrous substance. This fibrous matrix forms a rough net structure with a great deal of water and then a small amount of calcium is deposited. Matrix stones may be formed by this process and the calcigerous component might not be the primary constituent. are the
STONE ANALYSIS
All 12 stones were light tan in in cons1Stency and gritty. The matrix accounted 60 per cent of the dry weight. Infrared spectroscopic analysis revealed pure calcium phosphate at the inner part and magnesium ammonium phosphate at the outer part of these stones. Scanning electron microscopic analysis of the section through the center of the stones showed rough fibrous net structures with small depositions of calcium phosphate (parts A and B of figure), which were covered thinly with magnesium ammonium phosphate (part C of figure). DISCUSSION
Urinary stones usually contain crystalline salt as the main component and a small amount of matrix, which accounts for 2.5 per cent of the dry weight. 2 · 3 However, in matrix stones the matrix component accounts for approximately 65 per cent on the average, with values ranging from 42 to 84 per" cent of the dry weight. 2 In discussions of the derivation of urinary stones the precise role of matrix in stone formation has been a source of considerable confusion and speculation. There are 2 alternate viewpoints concerning this problem: 1) matrix is the primary constituent and a urinary stone is merely the consequence of its calcification2 and 2) matrix is simply an adventitious inclusion in what is basically a mineralogical process and it is necessary neither as a cement substance nor as a template. 4 · 5 While Allen and Spem:e are inclined to agree with the latter spectrum insofar as oxalate, uric acid and cystine stones, they do not believe that matrix stones can be explained on a purely mineralogical basis. 6 Our scanning electron microscopic findings show the rough fibrous net structures with small depositions of calcium phosphate at the center of the stones (parts A and B of figure), which is covered thinly by magnesium ammonium phosphate (part C of figure). These microstructural discoveries suggest that the fibrous net structure was formed first, followed by the small deposition of calcium phosphate until the deposition of magnesium ammonium phosphate covering this nucleus occurred. Therefore, the fibrous matrix is regarded as the primary constituent in the form of the stone nucleus.
ez,,useu.1111.(n
REFERENCES
1. Gage, H. and Beal, H. W.: Fibrous calculi in the kidney. Ann.
Surg., 48: 378, 1908. 2. Boyce, W. H. and King, J. S., Jr.: Crystal-matrix interrelations in calculi. J. Urol., 81: 351, 1959. 3. Mogg, R. A.: Matrix calculi. Proc. Roy. Soc. Med., 57: 935, 1964. 4. Finlayson, B., Vermeulen, C. W. and Stewart, E. J.: Stone matrix and mucoprotein from urine. J. Urol., 86: 355, 1961. 5. Vermeulen, C. W. and Lyon, E. S.: Mechanisms of genesis and growth of calculi. Amer. J. Med., 45: 684, 1968. 6. Allen, T. D. and Spence, H. M.: Matrix stones. J. Urol., 95: 284, 1966. 7. Mall, J.C., Collins, P.A. and Lyon, E. S.: Matrix calculi. Brit. J. Radio!., 48: 807, 1975. 8. Williams, D. I.: Matrix calculi. Brit. J. Urol., 35: 411, 1963.
THE JOURNAL OF UROLOGY
Copyright © 1977 by The Williams & Wilkins Co.
MATRIX STONES TAKUO KOIDE, MITSUO MIYAGAWA
AND
KATSUHIRO KINOSHITA
From the Ashiya City Hospital, Hyogo and the Department of Urology, Osaka University, Fukushima, Osaka, Japan
ABSTRACT
A scanning electron microscopic examination of matrix stones, which have been obtained from a 27-month-old Japanese boy with congenital hydronephrosis, revealed a rough fibrous net structure with small depositions of calcium phosphate. We believe that fibrous matrix may be the primary constituent and that the matrix stone may be the consequence of calcium deposition to it. Matrix stones, first described in 1908 as fibrous stones, 1 are yellowish-white to light tan in color and have a soft putty-like structure without any demonstrable nucleus. In ordinary crystalline stones the matrix accounts for 2.5 per cent of the dry weight but in matrix stones the comparable average is 65 per cent of the dry weight. 2 These stones may be entirely radiolucent or may contain faintly stippled calcification, which can be
CASE REPORT
A 27-month-old Japanese boy had left flank pain, fever and pyuria. Urine culture yielded Proteus .. A plain x-ray showed partially calcified shadows in the left kidney and an excretory urogram revealed left hydronephrosis owing to pelvioureteral junction stenosis.
Scanning electron microscopic examination on section through center of matrix stones reveals rough fibrous net structure with small depositions of calcium phosphate, which is covered thinly with magnesium ammonium phosphate. A, reduced from x 1,000. B and C, reduced from x3,000.
identified on a plain film. The vast literature on the derivation of urinary calculi recognizes and refers briefly to this rare type of calculus. Herein we present a reliable spectrum concerning matrix stone formation from scanning electron microscopy. Accepted for publication December 30, 1976. 786
Laboratory data included serum calcium 9.2, serum phosphate 4.4 mg. per 100 ml. and 24-hour urinary calcium excretion 22 mg. Pyelolithotomy and pyeloplasty were performed and 12 putty-like soft stones were removed. Postoperatively, the left hydronephrosis improved but urinary infection continued. Four months later a faintly stippled
787 calcified shado•u recurrence of a
vvh~ch
ths
the derivation of matrix stones low calcium content. matrix stones occur in the presence of urinary infection, especially by Proteus. 3 • 6-ll In our patient the Proteus infection had been indicated before and after the improvement of urinary stasis operation and a stone had recurred under this circumstance. Williams reported a similar case in which matrix stones recurred in an infected child after the elimination of urinary stasis. 8 These clinical courses suggest strongly the close relationship between urinary infection and matrix stone formation. The reason massive calcification does not occur in matrix stones has not been explained clearly. Diminished 24-hour urinary calcium excretion, often occurring in matrix stone formers, has been noted frequently. 2·" This low urinary calcium excretion might be related to the poor calcification of this type of stone. Although the 24-hour urinary calcium excretion was within the normal range in our patient a unilateral decrease in calcium excretion could be masked by a healthy opposite kidney." From these discussions and scanning electron microscopic findings we suggest a more reliable spectrum concerning the derivation of matrix stones. Some local conditions within the kidney, for example infection, injury or ·another disorder, cause the primary precipitation of the fibrous substance. This fibrous matrix forms a rough net structure with a great deal of water and then a small amount of calcium is deposited. Matrix stones may be formed by this process and the calcigerous component might not be the primary constituent. are the
STONE ANALYSIS
All 12 stones were light tan in in cons1Stency and gritty. The matrix accounted 60 per cent of the dry weight. Infrared spectroscopic analysis revealed pure calcium phosphate at the inner part and magnesium ammonium phosphate at the outer part of these stones. Scanning electron microscopic analysis of the section through the center of the stones showed rough fibrous net structures with small depositions of calcium phosphate (parts A and B of figure), which were covered thinly with magnesium ammonium phosphate (part C of figure). DISCUSSION
Urinary stones usually contain crystalline salt as the main component and a small amount of matrix, which accounts for 2.5 per cent of the dry weight. 2 · 3 However, in matrix stones the matrix component accounts for approximately 65 per cent on the average, with values ranging from 42 to 84 per" cent of the dry weight. 2 In discussions of the derivation of urinary stones the precise role of matrix in stone formation has been a source of considerable confusion and speculation. There are 2 alternate viewpoints concerning this problem: 1) matrix is the primary constituent and a urinary stone is merely the consequence of its calcification2 and 2) matrix is simply an adventitious inclusion in what is basically a mineralogical process and it is necessary neither as a cement substance nor as a template. 4 · 5 While Allen and Spem:e are inclined to agree with the latter spectrum insofar as oxalate, uric acid and cystine stones, they do not believe that matrix stones can be explained on a purely mineralogical basis. 6 Our scanning electron microscopic findings show the rough fibrous net structures with small depositions of calcium phosphate at the center of the stones (parts A and B of figure), which is covered thinly by magnesium ammonium phosphate (part C of figure). These microstructural discoveries suggest that the fibrous net structure was formed first, followed by the small deposition of calcium phosphate until the deposition of magnesium ammonium phosphate covering this nucleus occurred. Therefore, the fibrous matrix is regarded as the primary constituent in the form of the stone nucleus.
ez,,useu.1111.(n
REFERENCES
1. Gage, H. and Beal, H. W.: Fibrous calculi in the kidney. Ann.
Surg., 48: 378, 1908. 2. Boyce, W. H. and King, J. S., Jr.: Crystal-matrix interrelations in calculi. J. Urol., 81: 351, 1959. 3. Mogg, R. A.: Matrix calculi. Proc. Roy. Soc. Med., 57: 935, 1964. 4. Finlayson, B., Vermeulen, C. W. and Stewart, E. J.: Stone matrix and mucoprotein from urine. J. Urol., 86: 355, 1961. 5. Vermeulen, C. W. and Lyon, E. S.: Mechanisms of genesis and growth of calculi. Amer. J. Med., 45: 684, 1968. 6. Allen, T. D. and Spence, H. M.: Matrix stones. J. Urol., 95: 284, 1966. 7. Mall, J.C., Collins, P.A. and Lyon, E. S.: Matrix calculi. Brit. J. Radio!., 48: 807, 1975. 8. Williams, D. I.: Matrix calculi. Brit. J. Urol., 35: 411, 1963.
