Urinary Matrix Calculi: Report of 2 Cases

Liem, Robert K.T.; Kan, Michael K.

doi:10.1016/s0022-5347(17)60722-5

Cited by 7 publications

(2 citation statements)

References 9 publications

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“…l.2.U They were first described in 1908 as fibrous stones 6 and have also been referred to as urinary fibrinomas, fibrinous or colloid calculi, and albumin calculi. 7 Urinary matrix is a mucoprotein that constitutes less than 5% of the dry weight of crystalline stones and between 42% to 85% of matrix calculi. •.s…”

Section: Discussionmentioning

confidence: 99%

Renal matrix calculus. Sonographic appearance.

Zwirewich

Buckley²,

Kidney³

et al. 1990

Journal of Ultrasound in Medicine

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The typical sonographic appearance of urinary calculi includes strong internal echoes and sharp posterior acoustic shadowing. 1 .2 Although acoustic shadowing may not be visible from stones measuring less than 2 mm in diameter, reports of larger nonshadowing calculi are rare. 3 The sonographic appearance of urinary matrix calculi has not been described. We present a patient with a partially calcified, yet nonshadowing, renal matrix calculus of 4.5 em in diameter. CASE REPORTA 42-year-old quadriplegic male was referred to our institution for treatment of bilateral renal calculi using extracorporeal shock wave lithotripsy {ESWL). On admission, serum electrolytes, creatinine, calcium, phosphate, and uric acid were normal. Urinalysis showed marked proteinuria (5 g/L), and urine cultures grew enterococci. The excretory urogram demonstrated two small radiopaque calculi in the left kidney in addition to a smoothly marginated, faintly calcified, 4 X 3.5 em filling defect in the right pelvicalyceal system interpreted as a staghom calculus {Fig. 1). At our institution, patients with staghom calculi measuring greater than 3 em are initially treated with a percutaneous stone tract created under fluoroscopic control. This is followed by percutaneous urologic de-bulking through a nephroscope inserted into the tract. ESWL is then used to fragment residual calculi.The patient's initial ultrasound examination, performed using a 3.5-MHz mechanical sector transducer (Sonoline 2, Siemens, Iselin, NJ), identified two small shadowing calculi in the left kidney in addition to a solid mass with highly echogenic but nonshadowing margins in the right renal pelvis. Reexamination using phased array dynamic focus ultrasound equipment (Acuson 128, Acuson, Mountain View, CA) revealed a 4.5 X 3.7 X 2 em predominantly echo-poor mass in the right renal pelvis. Two thin echogenic layers were noted peripherally within the mass, producing a laminated appearance. No acoustic shadow was demonstrated even when the focal zone of the transducer was selectively placed at the level of the mass (Fig. 2). Sonography showed tubular extension of the mass into two lower pole infundibula. Neither hydron~ phrosis nor hydroureter was present and the renal parenchyma was normal in appearance.In view of the absence of acoustic shadowing, the sonographic appearance of the pelvicalyceal mass was judged to be atypical for a crystalline staghom calculus. To clarify the na~ ture of the mass, computed tomography (CI) was performed {Fig. 3). Nonenhanced scans showed the right renal pelvis expanded by a soft tissue mass containing discretely laminated peripheral calcification. Postcontrast scans showed that the mass did not enhance and that it lay entirely within the collecting system. The renal parenchyma was normal and no hydronephrosis was identified. A matrix calculus was considered the most likely diagnosis.A percutaneous stone tract was created under Ouoroscopic Received February 21, 1989, from the Departments of "Radiology control. At nephroscopy, a large tan-colored...

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Section: Discussionmentioning

confidence: 99%

Renal matrix calculus. Sonographic appearance.

Zwirewich

Buckley²,

Kidney³

et al. 1990

Journal of Ultrasound in Medicine

View full text Add to dashboard Cite

show abstract

“…This gas is probably secondary to active infection and may be responsible for the laminated stone appearance described on abdominal radiographs of patients with matrix calculi. 12 On retrograde pyelographic and excretory urographic studies, matrix stones should be included in the differential diagnosis of filling defects of the urinary tract such as blood clots, tumors, polyps, small uric acid or cystine stones, varices, ureteritis cystica and sloughed renal papillae. On abdominal radiographs or urographic films, the presence of multiple round radiolucent or faintly calcified filling defects in the collecting system associated with impaired kidney function suggests the possibility of matrix stones.…”

Section: Casementioning

confidence: 99%