Challenges in the diagnosis of calyceal diverticulum: A report of two cases and review of the literature

Abstract

Background: Calyceal diverticula outpouchings that occur rarely in the upper collecting system of the kidney and is often difficult to detect. In this study, we present two cases of calyceal diverticula and discuss their clinical characteristics and radiologic features. Patients and methods: In the presented two cases, we applied several imaging examinations, including delayed intravenous pyelography, retrograde pyelography and axial computerized tomographic (CT) scanning of the kidneys with and without contrast. Serum creatinine levels in fluid withdrawn from the diverticula were found to be significantly higher than the simultaneous serum creatinine levels. Intravenous injection of methylene blue through a ureteral catheter was also aided in the diagnosis. Calyceal diverticulum neck dilatation was performed through a percutaneous nephroscope. Results The two cases were diagnosed preoperatively and the operation was successful performed. The nephrostomy tube was removed seven days after surgery without complications. CT scans of the kidney after six months showed that the size of the calyceal diverticulum of two patients were considerably smaller than pre-surgery. There were no reports of pain in the lumbar region or other discomfort. Comments: Diagnosis of calyceal diverticulum mainly depend on a variety of imaging examinations, including the delayed intravenous pyelography, retrograde pyelography, and kidney CT plain scan plus enhanced scan. If the patient cannot be diagnosed by above methods, cyst fluid can be aspirated percutaneously to measure the preoperative creatinine level. If it is significantly higher than the serum creatinine level, the cyst fluid is considered urine, which can assist in the diagnosis of calyceal diverticulum. A ureteral catheter should also be inserted before operation namely, intravenous injection of methylene blue through a ureteral catheter is helpful for diagnosis. The choice of surgical treatment is based on the size and location of calyceal diverticulum and clinical manifestations.

A Case Report of Calyceal Diverticulum: Differential Diagnosis for Organ-Preserving Operations

“…Benign kidney lesions, such as calyceal diverticulum and intrarenal epidermal cyst, are rare and do not have specific clinical symptoms (1)(2)(3)(4)(5)(6)(7). However, they can be mistaken as kidney cancers leading to unjustified nephrectomy (2,4,5,7).…”

“…Calyceal diverticula are outpouchings from the calyx or pelvis with epithelial lining, muscular layer and narrow channel connecting the diverticulum cavity with the central collecting system ( 1 , 2 , 8 ). Their size ranges from 0.5 to 7.5 cm (average value is 1.72 cm) sometimes reaching 18 cm ( 1 ).…”

“…Their size ranges from 0.5 to 7.5 cm (average value is 1.72 cm) sometimes reaching 18 cm ( 1 ). Calyceal diverticula do not have gender or age predisposition and can be detected accidentally in 0.21–0.6% of adults and children performing intravenous pyelographic investigation ( 1 , 2 ). Diverticula are divided into two types: type I (calyceal diverticula) are more common, they communicate with a minor calyx and occur in the upper pole of the right kidney; type II (so called pyelocalyceal diverticula) communicate with a major calyx or the renal pelvis at the interpolar region of the kidney and tend to be larger ( 1 , 2 ).…”

“…The literature data shows that diverticula of the pelvicalyceal system and epidermoid cysts can be congenital pathologies occurring during the embryonic period (epidermal remnant of Wolffian duct, aberrant ectodermal implantation) or results of infection, vesicoureteral reflux, mechanical compression by the tumor, renal cyst rupture, urolithiasis causing squamous metaplasia, traumatic implantation or traumatic metaplasia because of surgical interventions ( 1 , 2 , 4 , 9 ). Pyelocalyceal diverticula and epidermal cysts have a non-specific clinical picture and require differential diagnosis with various benign and malignant neoplasms of the kidney ( 2 , 4 , 7 , 9 ). They can manifest with such symptoms as flank or loin pain, renal colic, urinary frequency, hematuria, infection or be asymptomatic.…”

“…At radiological examination, the diverticula of the pelvicalyceal system look like thin-walled cavities that communicate with the central collecting system. They can be empty or filled with urine, stones or milk of calcium ( 2 ). Epidermal cysts localized intrarenal or in the renal pelvis can form cavities filled with inhomogeneous calcified masses ( 4 , 7 ).…”