Nephrogenic adenoma of the bladder: Urographic spectrum

Nephrogenic adenoma is a rare, proliferative response of urothelium to urinary infection or injury of the bladder mucosa. Histologically, the lesion resembles proximal tubules of the nephron. While it can occur throughout the urinary tract, it usually appears in the bladder, with diverse radiographic manifestations. Of 6 patients with nephrogenic adenoma of the bladder, 3 presented with masses in the bladder and 2 with irregularities of the bladder mucosa on urography, while 1 showed no focal urographic abnormalities. There were no distinctive radiographic features of nephrogenic adenoma that would allow it to be differentiated from tumor or other inflammatory lesions. Although it is considered benign, bladder involvement may be extensive and eradication of the tumor may be difficult.     

Nephrogenic systemic fibrosis: Clinical spectrum of disease

Nephrogenic systemic fibrosis (NSF) is a rare systemic fibrosing disorder that primarily affects the skin and the subcutaneous structures. Also, there are reports of involvement of deeper structures and organs in the human body, but the confirmation of systemic involvement is complicated by overlap of other disease processes that occur in patients with severe renal impairment. The disorder leads to significant disability and is an important contributing factor of death. Virtually all patients who developed NSF suffered from endstage renal disease (ESRD) or severe chronic kidney disease (CKD) or from an acute acquired kidney injury (AKI). There is an increase in evidence that a causal relation between gadolinium‐based contrast agents (Gd‐CA) and NSF is probable. Therefore, advanced kidney injury and the exposure to Gd‐CA are regarded as prerequisites to develop NSF. Overall, the prognosis is poor and there is no established therapy that shows a consistent benefit. The purpose of this review is to discuss the clinical spectrum of the disease. The clinical presentation, role of co‐morbidity in disease development and manifestation, time course, prognosis, outcome, and epidemiological aspects are especially reviewed. J. Magn. Reson. Imaging 2009;30:1289–1297. © 2009 Wiley‐Liss, Inc.     

The urographic appearances of ureteric obstruction secondary to bladder carcinoma

It is usually assumed as a result of experiments that post-obstructive and hydronephrotic atrophy are due to raised intrapelvic pressure. In acute ureteric obstruction raised intrapelvic pressure is associated with renal colic; the absence of pain in chronic obstruction has been a stumbling block to acceptance of the back pressure theory. In ureteric obstruction due to bladder carcinoma the complete spectrum of nephrographic appearances ranging from those of high pressure obstruction to low pressure obstruction is seen in the absence of pain. This shows that acute ureteric obstruction may be painless and therefore post-obstructive and hydronephrotic atrophy may be preceded in man by a raised intrapelvic pressure. This removes the stumbling block.     

Microcystic adenoma of the pancreas: spectrum of computed tomographic findings

Fourteen cases of microcystic adenoma (serous cystadenoma) of the pancreas were reviewed and radiological findings were correlated with pathological specimens. Microcystic adenomas appeared grossly either as solid tumors with innumerable tiny cysts or as honeycombed cystic tumors depending on the size and number of cysts and amount of connective tissue. Dynamic enhanced CT of the tumor reflected the amount of connective tissue and appeared as (a) densely enhanced spongy masses (n = 6: classic appearance); (b) cystic masses with (n = 6) or without (n = 1) enhanced septa; or (c) dense diffusely enhanced mass (n = 1). Ultrasound similarly showed a variety of features such as echogenic masses with or without small cystic portions, multilocular cysts, or mixed hyperechoic and hypoechoic masses. The ultrasonic features mainly reflected the dominant sizes of cysts. Angiography almost always showed inhomogeneously hypervascular masses with tumor vessels. The imaging diagnosis is easy and conclusive in classic subtypes, but a correct diagnosis can be made even in other subtypes. However, mucinous cystic neoplasm can be confused with microcystic adenoma with large cysts and a small amount of connective tissue, and islet cell tumors can be mistaken for microcystic tumors with minute cysts.     

Computed tomography of nephrogenic adenoma of the urinary bladder

Nephrogenic adenoma of the urinary bladder is a rare benign tumor. It is generally accepted that the tumor represents metaplasia of the urothelium in response to chronic inflammation or injury. Its CT appearance can be similar to that of carcinoma of the bladder.     

CT imaging spectrum and the histopathological features of adult metanephric adenoma

Objective:

To retrospectively evaluate the radiopathological features of adult metanephric adenoma (MA) and explore whether MA can be differentiated on CT images, including the basis of their morphological features and enhancement patterns.

Methods:

18 consecutive MA cases (age range, 18–66 years; 9 males and 9 females) were pathologically proven and recruited in our study between January 2004 and June 2014. Unenhanced and contrast-enhanced CT were performed and correlated with corresponding pathological findings to differentiate between MA and other renal tumours. The enhancement pattern, lesion contour and presence of calcifications were evaluated.

Results:

On unenhanced CT scan, the most common (n = 15, 83.3%) CT imaging characteristics were the presence of homogeneity and well-defined solid renal masses; the minority (n = 3, 16.7%) were heterogeneous or centrally located low-attenuation masses. Contrast-enhanced CT image revealed hypoattenuating heterogeneous masses with varying degrees of contrast enhancement in 16 (88.9%) cases, in contrast to those without increased attenuation in 2 (11.1%) cases. Scattered calcification was found only in one case (5.6%). Pathological results revealed that a total of 6 (33.3%) cases had concomitant malignant carcinoma components; 2 (11.1%) patients had malignant MA; and pure MA was found in 10 cases, with a surprisingly high proportion of malignant tumours.

Conclusion:

The positive-predictive values of “high” enhancement seemed relatively characteristic for the diagnosis of malignant and composite MA.

Advances in knowledge:

Radiopathological features of adult MA and exploring whether MA can be differentiated on CT images, including the basis of their morphological features and enhancement patterns.Metanephric adenoma (MA) was first identified in 1979 and has been subsequently classified within the group of metanephric tumours, which comprise MAs, metanephric adenofibromas and metanephric stromal tumours.¹ The wide use of ultrasound, CT and MRI has led to an increase of incidentally discovered renal masses, including benign and malignant renal tumours. However, there are no unique and reliable radiological features for the differentiation of MA from renal cell carcinoma (RCC) and other benign renal tumours except for angioleiomyolipoma. There are no well-admitted criteria so this makes a diagnosis difficult; therefore, we performed the investigation focusing on CT imaging characteristics and corresponding pathological findings in order to establish CT diagnostic criteria of MA as the reference standard.     

Post-ERCP pancreatitis: association with urographic visualization during ERCP

To investigate the possible association of urographic visualization and acinarization of contrast material with postprocedure pancreatitis, 140 consecutive endoscopic retrograde cholangiopancreatograms (ERCP) with pancreatic duct filling were reviewed. Urographic visualization was identified in 29 patients (21%); pancreatitis developed in 13 of these patients (45%). Pancreatitis occurred in five of 111 patients (4%) without urographic visualization. Of 19 patients who demonstrated both acinarization and urographic visualization, ten (53%) had postprocedure pancreatitis. Twenty-six patients exhibited acinarization without urographic visualization; one (4%) had pancreatitis. Urographic visualization during ERCP is probably more common than generally recognized and indicates patients who are at high risk for postprocedure pancreatitis. Although acinarization accompanied by urographic visualization is associated with a high risk of pancreatitis, acinarization alone was not associated with this complication in this study. Detection of renal opacification during ERCP requires close scrutiny of films is best accomplished on overhead radiographs.     

Lacunae: a urographic finding in chronic obstructive uropathy

Lacunae, small spaces in the renal sinus that communicate with the caliceal fornices, have been mentioned rarely in the radiologic literature. These lesions have been reported to opacify during excretory urography in patients with current or previous urinary obstruction. Lacunae have been presumed to form in response to urine extravasation through the fornices, but there has never been gross anatomic or histologic proof of their existence. In two patients with obstructive uropathy, urographic-pathologic correlation confirmed the existence and nature of lacunae. On excretory urography, the appearance is likely to be confused with papillary necrosis.     

Nephrogenic systemic fibrosis: center case review

PURPOSE: To retrospectively analyze nephrogenic systemic fibrosis (NSF) cases at our center, to determine prior gadolinium based contrast agent (GBCA) administration and to evaluate possible common risk factors for the development of NSF by reviewing laboratory data and concurrent medications. MATERIALS AND METHODS: A total of four data bases (pathology, MRI, dialysis, and medical records) were cross-referenced for identification and evaluation of NSF patients. Medical history of NSF patients was assessed as for previous deep venous thrombosis (DVT), surgery, or infections. Laboratory data (creatinine, anion gap, calcium, phosphorus, and albumin) as well as concurrent medication were evaluated. Findings were compared to those of a control group of non-NSF dialysis patients. RESULTS: Between October 2003 and February 2007 a total of nine NSF cases were identified. All patients had undergone contrast-enhanced MRI prior to the diagnosis of NSF. Only one gadolinium chelate had been used at our MRI center (Omniscan, gadodiamide; GE Healthcare). Of nine patients, eight were receiving dialysis at the time of the MRI scan. During the same time 312 dialysis patients received gadodiamide. Thus, the prevalence of NSF within dialysis patients exposed to gadodiamide was 2.6%. NSF patients presented with a higher creatinine and anion gap than the control patients. Other laboratory values as well as medication did not show a significant difference. There were no patterns regarding previous history of DVT, surgery, or infection in the NSF group. CONCLUSION: Our findings are consistent with the previously reported association between gadodiamide exposure and NSF. All NSF patients had severe renal insufficiency with glomerular filtration rate (GFR) < 30 (highest GFR = 25 mL/minute) at the time of last gadodiamide administration, and on average had received 71 mL of gadodiamide over an average of 2.9 administrations.