Infantile polycystic kidney disease: an imaging dilemma

Infantile and adult type polycystic kidney diseases are 2 disparate genetic disorders and generally are easily distinguishable on the basis of clinical, pathologic, and radiologic findings. We present 3 children with infantile polycystic kidney disease, ages 9 months to 6 years, in whom the excretory urogram and/or renal ultrasound or gross anatomical appearance of the kidneys resembled adult polycystic kidney disease. The findings from these 3 patients emphasize the importance of renal and liver biopsies in the diagnosis of cystic kidney disease in young children.     

Infantile polycystic kidney disease: An imaging dilemma

Infantile and adult type polycystic kidney diseases are 2 disparate genetic disorders and generally are easily distinguishable on the basis of clinical, pathologic, and radiologic findings. We present 3 children with infantile polycystic kidney disease, ages 9 months to 6 years, in whom the excretory urogram and/or renal ultrasound or gross anatomical appearance of the kidneys resembled adult polycystic kidney disease. The findings from these 3 patients emphasize the importance of renal and liver biopsies in the diagnosis of cystic kidney disease in young children.     

Increased renal parenchymal echogenicity in the fetus: importance and clinical outcome

Pre- and postnatal ultrasound (US) findings and clinical course in 19 fetuses (16-40 menstrual weeks) with hyperechoic kidneys (renal echogenicity greater than that of liver) and no other abnormalities detected with US were evaluated to determine whether increased renal parenchymal echogenicity in the fetus indicates renal disease. Four infants (21%) were healthy at birth and had normal postnatal sonograms. Another 10 infants (53%) survived, but abnormalities were found at neonatal US. Postnatal diagnoses in these 10 neonates included unilateral renal dysplasia (n = 3), unilateral multicystic dysplastic kidney and a contralateral hyperechoic kidney (n = 2), hydronephrosis (n = 2), and renal abnormalities of unknown type (n = 3). Five fetuses with either infantile polycystic kidney disease (n = 4) or bilateral multicystic dysplasia (n = 1) did not survive. Oligohydramnios was predictive of a poor prognosis. Hyperechoic renal parenchyma in the fetus was associated with sonographic or functional abnormalities in 15 of 19 cases (79%) and a 74% survival rate.     

Autosomal dominant polycystic kidney disease: MR imaging evaluation using current techniques

PURPOSE: To determine the MR imaging findings of autosomal dominant polycystic kidney disease using current imaging techniques. MATERIALS AND METHODS: We reviewed our five-year experience with MR imaging of autosomal dominant polycystic kidney disease (ADPKD) to determine the spectrum of appearance of kidney disease, the occurrence of cysts in other abdominal organs, the size and number of cysts in the kidneys and other organs, and the association with other benign or malignant disease. Thirty patients (17 men and 13 women, age range 30 to 88 years old) with ADPKD were included in this study. All patients were examined by MR imaging including T2-weighted single-shot echo-train spin-echo and pre- and post-gadolinium chelate spoiled gradient-echo imaging. RESULTS: All kidneys were involved with multiple, varying sized cysts scattered throughout the parenchyma. Giant renal cysts (>8 cm) were associated with pain in the only two patients who possessed them. Hemorrhage in renal cysts was observed in all kidneys with a heterogeneous pattern of involvement on non-contrast T1- and T2-weighted images, reflecting hemorrhage of varying age. The mean kidney size for the right kidney was 17.4 cm in length, 10.3 cm in transverse, and 9.4 cm in antero-posterior diameter (AP); and for the left kidney, 15.9 cm in the length, 9.3 cm in the transverse, and 9.3 cm in AP diameter. Other organs involved included the liver (22 patients), the pancreas (three patients), with two of the above-mentioned patients having both liver and pancreas cysts, and the spleen (one patient) who had both liver and splenic cysts. Massive liver involvement with large cysts was associated with abdominal pain. Malignant disease was present in five patients, including two patients with renal cell carcinoma, one with bladder cancer, one with lung cancer, and one patient with anal adenocarcinoma. Comparison of pre- and post-contrast T1-weighted images was essential to detect renal cancer. CONCLUSION: All kidneys in patients with ADPKD had extensive, varying-sized cysts and in all cases some cysts showed evidence of hemorrhage. The liver was the second most common organ to be involved with cystic disease, in 73% of patients. Large cysts in the kidneys and liver were associated with abdominal pain.     

Volumetric measurement of renal cysts and parenchyma using MRI: phantoms and patients with polycystic kidney disease

We have developed an MR method to measure the volumes of renal cysts and parenchyma in patients with polycystic kidney disease. Phantoms were designed to simulate polycystic kidneys. Four patients were recruited. MR scans were performed on the phantoms and patients. A stereology technique was applied for image segmentation and volume measurement. Volumetric measurement of renal cysts and parenchyma was accurate in phantom studies and reliable in both phantom and patient studies in these limited examples.     

Polycystic kidneys: a cautionary story

We describe the imaging appearances of a patient with bilateral, synchronous, multiloculated renal cell carcinoma with a predominantly cystic nature. The patient had progressive chronic renal failure. He was initially erroneously diagnosed as having autosomal dominant polycystic kidney disease (ADPKD) on the basis of the imaging findings. We believe this to be the first report describing bilateral synchronous renal carcinomas replacing the renal parenchyma imitating ADPKD.     

Sonography of infantile polycystic kidney disease

Seven children aged 1 day to 12 years with infantile polycystic kidney disease (IPCD) were evaluated by a new high-resolution real-time ultrasound scanner. Instead of the monotonous increased echogenicity of renal parenchyma seen with earlier ultrasound equipment, the echo texture of IPCD became more differentiated, showing disseminated tiny cysts associated with high-amplitude echoes. Even in the newborn, cysts as small as 2 mm in diameter could be detected. Analysis of the new sonographic features of IPCD reveals specific “pepper and salt” and “striped” patterns. In association with such well-known sonographic findings as bilateral enlarged kidneys and poor definition of renal sinus, medulla, and cortex, this pattern allows one to make the final diagnosis of IPCD.     

Sonography of infantile polycystic kidney disease

Seven children aged 1 day to 12 years with infantile polycystic kidney disease (IPCD) were evaluated by a new high-resolution real-time ultrasound scanner. Instead of the monotonous increased echogenicity of renal parenchyma seen with earlier ultrasound equipment, the echo texture of IPCD became more differentiated, showing disseminated tiny cysts associated with high-amplitude echoes. Even in the newborn, cysts as small as 2 mm in diameter could be detected. Analysis of the new sonographic features of IPCD reveals specific "pepper and salt" and "striped" patterns. In association with such well-known sonographic findings as bilateral enlarged kidneys and poor definition of renal sinus, medulla, and cortex, this pattern allows one to make the final diagnosis of IPCD.     

Incidental finding of autosomal dominant polycystic kidney disease with liver involvement on Tc-99m sestamibi scintigraphy

Autosomal dominant polycystic kidney disease is a systemic hereditary disease characterized by renal cysts and sometimes involvement of the liver. We present a 65-year-old woman with autosomal dominant polycystic kidney disease on regularly hemodialysis who recently experienced intermittent right upper quadrant abdominal pain and elevated intact parathyroid hormone for more than a year. She was referred for double-phase Tc-99m sestamibi scintigraphy, under the impression of hyperparathyroidism. Apart form increased uptake in the right thyroid bed, the images showed a large photon-deficient area in the upper portion of the abdomen corresponding to the liver.     

Autosomal recessive (infantile) polycystic kidney disease demonstrated by Tc-99m DMSA renal imaging.

A neonate with infantile polycystic kidney disease underwent Tc-99m DMSA imaging. The pattern of uptake in infantile polycystic disease is different from the multiple cystic lesions reported in the literature for adult polycystic kidney disease. The infantile pattern of uptake shows large kidneys with diffuse, symmetric localization of the radiopharmaceutical, which seems to be characteristic and may be pathognomonic of the disease process.     

Imaging of renal cystic diseases

The improved understanding of hereditary cystic diseases is changing the nomenclature used to describe these diseases. Detailed family studies of the inheritance of these conditions become possible as the genes involved, or their DNA markers, are identified. At the same time, ultrasonography allows cystic disease to be detected very early in life in some patients. The new information necessitates changes in the terminology, which was based previously on the patient's age at clinical presentation. Thus, because ultrasonography now sometimes identifies the cysts of adult polycystic kidney disease in utero or in neonates, the term autosomal dominant polycystic kidney disease is now more appropriate. Similarly, the term autosomal recessive polycystic kidney disease is replacing infantile polycystic kidney disease. Despite the success of ultrasonography in identifying the cysts of these and other inherited conditions very early, it is important to appreciate that precise definition of the type and heredity of the condition concerned requires detailed pathologic and genetic studies. The other renal cystic disease receiving considerable attention in the recent literature is acquired cystic disease, about which more data are accumulating. With increasing numbers of patients on long-term dialysis, the condition and its complications, especially renal adenocarcinoma but also hemorrhage, continue to cause concern. The evidence for an increased incidence of renal cell carcinoma has strengthened over recent years, and the debate on the need for CT screening of patients on long-term dialysis continues.     

From the Archives of the AFIP. Xanthogranulomatous pyelonephritis.

Xanthogranulomatous pyelonephritis is a form of chronic infection of the kidney and surrounding tissues characterized by destruction and replacement of renal parenchyma by lipid-laden macrophages. Gross pathologic features include massive renal enlargement, lithiasis, peripelvic fibrosis, hydronephrosis, and lobulated yellow masses replacing renal parenchyma. Typically, the disease is diffuse and has characteristic imaging features. Less commonly, the process is focal and is difficult to differentiate from malignant disease on radiologic studies. Ultrasound demonstrates renal enlargement with multiple anechoic or hypoechoic masses replacing the normal corticomedullary differentiation and a contracted pelvis. Peripelvic fibrosis may obscure acoustic shadowing from a central staghorn calculus. On computed tomographic scans, a staghorn calculus may be seen in a contracted renal pelvis of an enlarged kidney, with characteristic low-attenuation, peripherally enhancing rounded masses. Extrarenal extension of the inflammatory process is frequently seen.     

Fetal renal cystic disease: sonographic-pathologic correlation

Renal cystic disease encompasses a complex group of pathologic and clinical entities, with varied yet distinctive sonographic features. An accurate assessment of the fetal genitourinary tract and the amniotic fluid volume by sonography can lead to a specific prenatal diagnosis in most cases. This article emphasizes the usefulness of sonographic-pathologic correlation in understanding renal cystic disease. The entities discussed are infantile polycystic kidney disease (Osathanondh and Potter type I), multi-cystic renal dysplasia (type II), adult polycystic kidney disease (type III) and renal cystic dysplasia associated with obstructive uropathy (type IV). Sonograms of six correctly diagnosed cases between November 1982 and November 1984 were retrospectively reviewed and correlated with their pathologic findings. The differential diagnosis and possible pitfalls are discussed. In addition, the impact on perinatal management and the role of genetic counselling will be emphasized.     

Broncheoalveolar carcinoma associated with pulmonary lymphangioleiomyomatosis and Tuberous Sclerosis Complex: case report

Lymphangioleiomyomatosis (LAM) is a rare disorder that predominantly affects the lung parenchyma of young women and it's characterized by pulmonary cyst. Tuberous sclerosis complex (TSC) is a rare genetic disorder presenting with hamartomas and neurologic symptoms. The two renal pathologies most commonly seen in TSC are angiomyolipomas and cysts; less commonly, TSC co-exist with polycystic kidney disease. In this report is described an uncommon case of a patient with broncheoalveolar carcinoma, pulmonary LAM and TSC with polycystic kidney disease.     

Unilateral renal cystic disease

Unilateral renal cystic disease (URCD) is a distinct entity that is one of the renal cystic diseases. URCD consists of a cluster of multiple cysts in part or most of one kidney with no association of cystic disease in the contralateral kidney. URCD is a nonfamilial, nonprogressive disorder and is not related with autosomal dominant polycystic kidney disease (ADPKD). We report a case of URCD with six-year CT follow-up. Confinement of the cystic disease to one kidney with an absence of cysts in other organs such as liver or pancreas distinguish URCD from ADPKD. Absence of an encapsulated mass and intervening normal renal parenchyma between the cysts can differentiate URCD from cystic renal tumors.     

Unilateral renal cystic disease: CT findings

Unilateral renal cystic disease (URCD) is characterized by replacement of most of one kidney by multiple cysts scattered diffusely throughout the parenchyma without the formation of a distinct, encapsulated renal mass. There are no cysts in the opposite kidney or liver. The condition is nonfamilial and does not cause renal functional impairment. We describe the clinical and radiologic findings in two patients with URCD and discuss how the disorder usually can be distinguished from other renal cystic diseases using CT. Absence of a family history of renal cystic disease and the normality of the other kidney help distinguish URCD from autosomal dominant polycystic kidney disease. The diffuse nature of the cysts in URCD and the absence of a distinct encapsulated renal mass help distinguish URCD from cystic renal neoplasms.     

Angiographic patterns of involvement in renal and perirenal lymphoma

Ten patients with renal lymphoma studied by selective angiography are reported. Seven patients had unilateral and 3 had bilateral involvement. A localized mass was seen in 6 patients and diffuse infiltration in 3. In 1 patient with bilateral nodular involvement, the angiographic findings resembled those of adult-type polycystic kidney disease. In all cases, renal lymphoma was suspected angiographically. The findings included hypovascular mass or masses with fine neovascularity, smooth and diffuse arterial encasement, and faint tumor staining.     

Localized cystic disease of the kidney

OBJECTIVE: Localized cystic disease of the kidney is a benign nonsurgical condition. Its imaging and clinical features are characterized and differentiated from autosomal dominant polycystic kidney disease, multilocular cystic nephroma, and cystic neoplasm. MATERIALS AND METHODS: Localized cystic disease was diagnosed in 18 patients on the basis of a review of imaging studies, clinical histories, and pathologic proof in four of the 18 patients. Average age at diagnosis was 54 years (age range, 24-83 years). Fifteen of the patients (83%) were men. CT was performed on 18 patients, sonography on nine, excretory urography on six, arteriography on four, and MR imaging on two. RESULTS: Localized cystic disease was unilateral in all patients and characterized by multiple cysts of various sizes separated by normal (or atrophic) renal tissue in a conglomerate mass suggestive of cystic neoplasm. In some patients, involvement of the entire kidney, which was suggestive of unilateral autosomal dominant polycystic kidney disease, was seen. No cysts were seen in the contralateral kidney in 14 patients, and only one or two scattered small cysts were present in four patients. Clinical presentations included hematuria, flank pain, palpable abdominal mass, and localized cystic disease as an incidental finding. None of the patients had a family history of autosomal dominant polycystic kidney disease. Ten patients underwent follow-up (follow-up range, 1-12 years); nine patients underwent imaging follow-up and one patient underwent clinical follow-up, which showed stability of disease. Four patients underwent nephrectomy for suspected renal neoplasm. CONCLUSION: Familiarity with localized cystic disease of the kidney and its imaging findings is important to avoid unnecessary surgery and to differentiate the disease from autosomal dominant polycystic kidney disease.     

Renal compensatory hypertrophy in the adult.

Compensatory renal enlargement was assessed in 19 adult patients who either had a nephrectomy (17 cases) or developed a functionless kidney following obstruction (two cases). Hypertrophy of the healthy kidney was assessed by comparing renal size on urography before and after removal or destruction of the diseased kidney. Compensatory renal enlargement was demonstrated in 40 per cent of the patients, including two patients in their sixties. The average increase in length was 3 per cent and the maximum increase in length was 9 per cent. Therefore compensatory enlargement does occur in adult life, but is much less than that occurring in childhood. The presence of a hypertrophied adult kidney over 17 cm in length usually indicates that the contralateral renal disease was present in childhood.     

Gallium-67 scintigraphy in the detection of infected polycystic kidneys in renal transplant recipients

Renal transplant recipients with underlying polycystic kidney disease (PKD) may present with recurrent urinary tract infection (UTI). This is often due to persistent infection in one or both of the native polycystic kidneys. It may be necessary to remove the infected kidney in order to remove the source of persistent infection. Gallium-67 scintigraphy was performed in 11 renal transplant recipients with underlying PKD. Positive studies were obtained in four recipients who had recurrent UTI. The scan also localized which of the kidneys (native or transplant) was the site of persistent infection. These four recipients subsequently had nephrectomy of the infected polycystic kidneys as suggested by the scan. Negative scans were obtained in seven recipients who did not have recurrent UTI. Gallium scintigraphy is a useful test for detecting and localizing the site of persistent UTI in renal transplant recipients with underlying PKD who present with recurrent UTI.