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Quiz Page Answers December 2006
AJKD
QUIZ PAGE ANSWERS DECEMBER 2006
A 39-year-old woman was admitted for right flank pain. Her past history disclosed right lower back discomfort, occasional urinary infections, and nephrolithiasis. On admission, her blood pressure was 135/90 mm Hg, blood urea nitrogen level was 8.3 mg/dL (2.9 mmol/L), and serum creatinine level was 1.06 mg/dL (93.7 mol/L). Urinalysis revealed the presence of red blood cells, leukocytes, and 2⫹ blood. An intravenous pyelogram was obtained.
Figure 58B. Intravenous pyelogram showing normal-sized kidneys with bilateral discrete linear papillary densities, and a “paint-brush” appearance in the medullary areas just before the calyx.
What is your diagnosis? Precalyceal canalicular ectasia also is known as medullary sponge kidney, Cacchi-Ricci disease, tubular-ectasia, or cystic-dilatation of renal collecting tubes.1 The “pyramidal blush” is due to accumulation of contrast medium in dilated collecting ducts and distal tubular structures within the papilla just before the calyx. It may affect both kidneys, as in our case, but involvement also may be unilateral or affect only a few papillae. Collections of contrast medium in ectatic papillary ducts may give the appearance of a blush (in the mildest cases), linear striations as in our patient (“paint-brush” appearance), or of “bouquets” of papillae when cystic dilation of the collecting ducts is seen. Medullary sponge kidney is a congenital renal malformation characterized by ectasia along the intrapyramidal or intrapapillary portion of the medullary collecting duct. A clear genetic basis has not been established, and ⬍5% of cases are familial. The prevalence is difficult to estimate, because many cases are asymptomatic and only incidentally discovered on intravenous urography. Approximately 0.5% to 1% of asymptomatic individuals who undergo renal imaging studies for assorted clinical indications eventually show medullary sponge kidney. No systematic autopsy studies have been performed to define the prevalence. Patients are usually aged 20 to 50 years at presentation.2,3 Prognosis largely depends on the occurrence of complications from tubular defects coupled with urine stasis in the dilated tubuli, such as hypercalciuria, hypocitraturia, urinary acidification and concentration defects, recurrent stones, medullary nephrocalcinosis, and superimposed infections. Medullary sponge kidney is usually a nonprogressive, asymptomatic condition. However, in the presence of repeated urinary infection and stones, chronic kidney disease may occur and may rarely cause end-stage kidney disease, especially in women. Medullary sponge kidney occurs more frequently among individuals with a variety of other congenital defects, including congenital hemihypertrophy, Beckwith–Wiedemann syndrome, Caroli disease, and Ehlers–Danlos syndrome.4,5
AJKD
QUIZ PAGE ANSWERS (continued)
Medullary sponge kidney should be considered in patients with recurrent kidney stones (up to 20% of adults with kidney stones may have medullary sponge kidney), recurrent gross hematuria (recurrent gross hematuria may occur in 10% to 20%), and recurrent urinary infections (up to 5% of males and 35% of females have urinary infections). An intravenous pyelogram should be obtained to make the diagnosis.5
Final diagnosis: Medullary sponge kidney. Case provided by Piero Stratta, MD, Caterina Canavese, MD, Elisa Lazzarich, MD, Roberta Fenoglio, MD, Veronica Morellini, MD, Marco Quaglia, MD, and Maddalena Brustia, MD, Department of Nephro-Urology, Amedeo Avogadro University, Maggiore Hospital Medicine; Nephrology Division, University of Torino; and Department of Human and Hereditary Pathology, University of Pavia, Italy.
If you have an interesting case you would like to submit for consideration, please go to http://ajkd.edmgr.com to do so. REFERENCES 1. Cacchi R, Ricci V: Sur une rare maladie kystique multiple des pyramids rénales le ‘Rein en éponge.’ J Urol 55:499-519, 1949 2. Rommel D, Pirson Y: Medullary sponge kidney—Part of a congenital syndrome. Nephrol Dial Transplant 16:634636, 2001 3. Gambaro G, Feltrin GP, Lupo A, Bonfante L, D’Angelo A, Antonello A: Medullary sponge kidney (LenarduzziCacchi-Ricci disease): A Padua Medical School discovery in the 1930s. Kidney Int 69:663-670, 2006 4. Chesney RW, Kaufman R, Stapleton FB, Rivas ML: Association of medullary sponge kidney and medullary dysplasia in Beckwith-Wiedemann syndrome. J Pediatr 115: 761-764, 1989 5. Diouf B, Ka EH, Calender A, Giraud S, Diop TM: Association of medullary sponge kidney disease and multiple endocrine neoplasia type IIA due to RET gene mutation: Is there a causal relationship? Nephrol Dial Transplant 15:2062-2063, 2000 Support: None. Potential conflicts of interest: None.
QUIZ PAGE ANSWERS DECEMBER 2006
A 39-year-old woman was admitted for right flank pain. Her past history disclosed right lower back discomfort, occasional urinary infections, and nephrolithiasis. On admission, her blood pressure was 135/90 mm Hg, blood urea nitrogen level was 8.3 mg/dL (2.9 mmol/L), and serum creatinine level was 1.06 mg/dL (93.7 mol/L). Urinalysis revealed the presence of red blood cells, leukocytes, and 2⫹ blood. An intravenous pyelogram was obtained.
Figure 58B. Intravenous pyelogram showing normal-sized kidneys with bilateral discrete linear papillary densities, and a “paint-brush” appearance in the medullary areas just before the calyx.
What is your diagnosis? Precalyceal canalicular ectasia also is known as medullary sponge kidney, Cacchi-Ricci disease, tubular-ectasia, or cystic-dilatation of renal collecting tubes.1 The “pyramidal blush” is due to accumulation of contrast medium in dilated collecting ducts and distal tubular structures within the papilla just before the calyx. It may affect both kidneys, as in our case, but involvement also may be unilateral or affect only a few papillae. Collections of contrast medium in ectatic papillary ducts may give the appearance of a blush (in the mildest cases), linear striations as in our patient (“paint-brush” appearance), or of “bouquets” of papillae when cystic dilation of the collecting ducts is seen. Medullary sponge kidney is a congenital renal malformation characterized by ectasia along the intrapyramidal or intrapapillary portion of the medullary collecting duct. A clear genetic basis has not been established, and ⬍5% of cases are familial. The prevalence is difficult to estimate, because many cases are asymptomatic and only incidentally discovered on intravenous urography. Approximately 0.5% to 1% of asymptomatic individuals who undergo renal imaging studies for assorted clinical indications eventually show medullary sponge kidney. No systematic autopsy studies have been performed to define the prevalence. Patients are usually aged 20 to 50 years at presentation.2,3 Prognosis largely depends on the occurrence of complications from tubular defects coupled with urine stasis in the dilated tubuli, such as hypercalciuria, hypocitraturia, urinary acidification and concentration defects, recurrent stones, medullary nephrocalcinosis, and superimposed infections. Medullary sponge kidney is usually a nonprogressive, asymptomatic condition. However, in the presence of repeated urinary infection and stones, chronic kidney disease may occur and may rarely cause end-stage kidney disease, especially in women. Medullary sponge kidney occurs more frequently among individuals with a variety of other congenital defects, including congenital hemihypertrophy, Beckwith–Wiedemann syndrome, Caroli disease, and Ehlers–Danlos syndrome.4,5
AJKD
QUIZ PAGE ANSWERS (continued)
Medullary sponge kidney should be considered in patients with recurrent kidney stones (up to 20% of adults with kidney stones may have medullary sponge kidney), recurrent gross hematuria (recurrent gross hematuria may occur in 10% to 20%), and recurrent urinary infections (up to 5% of males and 35% of females have urinary infections). An intravenous pyelogram should be obtained to make the diagnosis.5
Final diagnosis: Medullary sponge kidney. Case provided by Piero Stratta, MD, Caterina Canavese, MD, Elisa Lazzarich, MD, Roberta Fenoglio, MD, Veronica Morellini, MD, Marco Quaglia, MD, and Maddalena Brustia, MD, Department of Nephro-Urology, Amedeo Avogadro University, Maggiore Hospital Medicine; Nephrology Division, University of Torino; and Department of Human and Hereditary Pathology, University of Pavia, Italy.
If you have an interesting case you would like to submit for consideration, please go to http://ajkd.edmgr.com to do so. REFERENCES 1. Cacchi R, Ricci V: Sur une rare maladie kystique multiple des pyramids rénales le ‘Rein en éponge.’ J Urol 55:499-519, 1949 2. Rommel D, Pirson Y: Medullary sponge kidney—Part of a congenital syndrome. Nephrol Dial Transplant 16:634636, 2001 3. Gambaro G, Feltrin GP, Lupo A, Bonfante L, D’Angelo A, Antonello A: Medullary sponge kidney (LenarduzziCacchi-Ricci disease): A Padua Medical School discovery in the 1930s. Kidney Int 69:663-670, 2006 4. Chesney RW, Kaufman R, Stapleton FB, Rivas ML: Association of medullary sponge kidney and medullary dysplasia in Beckwith-Wiedemann syndrome. J Pediatr 115: 761-764, 1989 5. Diouf B, Ka EH, Calender A, Giraud S, Diop TM: Association of medullary sponge kidney disease and multiple endocrine neoplasia type IIA due to RET gene mutation: Is there a causal relationship? Nephrol Dial Transplant 15:2062-2063, 2000 Support: None. Potential conflicts of interest: None.