Megacalycosis: a rare condition

Unique Variants of Megacalycosis on Magnetic Resonance Urography

OBJECTIVE

To present a unique set of patients diagnosed with megacalycosis by magnetic resonance urography (MRU) to re-evaluate the definition of megacalycosis and provide a new perspective on diagnosis and treatment.

MATERIALS AND METHODS

A retrospective chart review of patients with megacalycosis as diagnosed by MRU was conducted. MRU was performed to determine the presence of obstruction, further visualize renal anatomy, and clarify the presence of megacalycosis. Patients who were asymptomatic and demonstrated no evidence of obstruction were managed with long-term observation through renal bladder ultrasonography, and symptomatic patients who showed evidence of obstruction (crossing vessels, abnormal renal transit time, or disparity in differential renal function of <40%) were treated surgically with a dismembered Anderson-Hynes pyeloplasty.

RESULTS

Thirteen cases of megacalycosis were identified as diagnosed by MRU at our institution between 2007 and 2020. In 7 patients (54%), MRU revealed the simultaneous occurrence of obstruction and megacalycosis. In patients with obstruction (N = 7), surgical intervention was required to correct the obstruction via robotic pyeloplasty. In patients without obstruction (N = 6), conservative management was performed to monitor megacalycosis through long-term follow-up via routine ultrasounds.

CONCLUSION

While megacalycosis has historically referred to the non-obstructive dilatation of the renal calyces, our study presents 7 cases of obstruction occurring simultaneously with megacalycosis as diagnosed by MRU. By expanding the designation of megacalycosis to include patients with obstruction, surgical treatment can be explored to prevent future renal colic and/or renal deterioration in those patients.

Nuclear medicine and pediatric nephro-urology: a long-lasting successful partnership

Congenital anomalies of the kidney and urinary tract, as well as urinary infections, are very frequent in children. After the clinical and laboratory evaluation, the first imaging procedure to be done is a renal and bladder ultrasound, but afterwards, a main contribution comes from nuclear medicine. Through minimally invasive and sedation-free procedures, nuclear medicine allows the evaluation of the functional anatomy of the urinary tract, and the quantification of renal function and drainage. If pediatric dosage cards provided by scientific societies are used, radiation exposure can also be low. In the pediatric conditions previously mentioned, nuclear medicine is used both for initial diagnosis and follow-up, mostly in cases of suspicion of ureteropelvic or ureterovesical junction syndromes, as well as vesicoureteral reflux or renal scars of febrile infectious episodes. Pediatric nephro-urology constitutes a significant workload of pediatric nuclear medicine departments. The following paragraphs are a revision of the renal radiopharmaceuticals, as well as the nuclear nephro-urology procedures - dynamic and static renal scintigraphy, and direct and indirect radionuclide cystography. A summary of the techniques, main indications, interpretation criteria and pitfalls will be provided. Some future directions for the field are also pointed out, among which the most relevant is the need for nuclear medicine professionals to use standardized protocols and integrate multidisciplinary teams with other pediatric and adult health professionals that manage these life-long pediatric pathologies, which are recognized as an important cause of adult chronic kidney disease.

Staghorn stone in megapolycalicosis in a child: Still the case for open surgery? Case report

We here report a rare case of congenital megapolycalicosis in a 14-year-old girl complicated by a 24-mm staghorn stone and numerous calculi at the level of all caliceal groups that had become symptomatic in recent weeks with malaise, hematuria, and urinary tract infection. Among the various therapeutic options, we opted for open surgery. The staghorn stone was removed by pyelotomy, and washout of the caliceal cavities released numerous microcalculi of 1.5−9 mm in size that were then removed. To our knowledge, this is the first case of pediatric megacapolycalicosis complicated by staghorn stone, which presents complex problems for the diagnosis and therapy.

MDCT and MR Urogram Spectrum of Congenital Anomalies of the Kidney and Urinary Tract Diagnosed in Adulthood

OBJECTIVE

Congenital anomalies of the kidneys and urinary tract (CAKUT) encompass a spectrum of anomalies that result from genetic, epigenetic, environmental, and molecular signal aberrations at key stages of urinary tract development. CAKUT can be seen incidentally on cross-sectional imaging of the abdomen or can be a cause for adult-onset chronic kidney disease, posing new challenges for nephrologists, urologists, and radiologists.

CONCLUSION

Awareness of CAKUT and familiarity with their imaging findings permit optimal patient management and thorough workup to prevent hypertension and progression from CAKUT to renal failure. The purpose of this article is to review the cross-sectional imaging findings of CAKUT that may present in adulthood.

Radiological findings and the clinical importance of megacalycosis

Objective

To describe the radiological findings and the clinical importance of megacalycosis.

Materials and methods

On the basis of a case report and literature review, diagnostic criteria and clinical significance of megacalycosis are presented.

Result

Megacalycosis is mostly asymptomatic and is usually discovered either accidentally or as a result of its complications, such as stone formation, flank pain, hematuria, infection, and fever. The renal pelvis, infundibulum, and ureter are not dilated. Calyces have a semilunar configuration rather than the conventional triangular or conical form. The tip of each pyramid is flat, and the calyces possess neither fornix nor papillae impressions. The number of calyces is increased compared to the healthy condition, typically from 20–25. The renal parenchyma has a normal width but with a slight narrowing of the renal medulla. The kidney exhibits normal function, in particular with respect to its ability to concentrate the urine.

Conclusion

Megacalycosis is a rare, usually unilateral dilatation of the kidney calyces in the presence of a normal, undilated renal pelvis and ureter. Its pathological significance lies in the occurrence of complications.

Congenital megacalycosis with IgA nephropathy: a case report and review of the literature

Congenital megacalycosis is a rare renal disease characterized by calyceal dilatation without pelvic or ureteral obstruction. If not accompanied by nephrolithiasis and urinary tract infection, this disease is completely benign and does not cause renal dysfunction. We present a case of congenital megacalycosis that was diagnosed at the age of 41 (oldest case in the literature) after admitting with hematuria and acute renal dysfunction. IgA nephropathy was also diagnosed in this patient. Since renal dysfunction is not likely in these patients, if encountered; renal biopsy should be performed although technically difficult to diagnose the cause of this dysfunction.