CASE 9959 Published on 11.07.2012

Stone-containing caliceal diverticulum


Uroradiology & genital male imaging

Case Type

Clinical Cases


Oliveira C1, Candelária I1, Coelho H2, Catarino R1

1 - Radiology Department, Centro Hospitalar e Universitário de Coimbra
2 - Urology Department, Centro Hospitalar e Universitário de Coimbra

26 years, male

Area of Interest Kidney, Abdomen ; Imaging Technique Ultrasound, Conventional radiography
Clinical History
Patient presented to the ER department with flank pain, fever and vomiting. He had no other symptoms or relevant laboratory findings.
Imaging Findings
Renal ultrasound (US) showed a regular cystic-like lesion, 25 mm in diameter, located in the upper right kidney pole. Bright mobile focus was visible within the cyst-like lesion, with a low acoustic posterior shadow (Fig. 1).
Plain abdominal film detected small, round calcifications in the area of the right kidney, without any other significant abnormalities (Fig. 2).
On intravenous urography (IVU), the cyst-like lesion showed opacification with contrast medium, in a late pyelographic phase, confirming its connection with the pyelocalyceal system (Fig. 3).
Pyelocaliceal diverticula (PCD) are relatively uncommon cyst-like structures in the renal parenchyma, often discovered incidentally during ultrasound examination. Two important features differentiate them from cysts: they are lined with transitional cell epithelium and connect to the renal pelvis or a calix by a small channel also lined by urothelium. Diverticula related to a minor calix are usually located in the upper pole, while those connected with the pelvis or a major calix are located in the central portion of the kidney [1].
Rarely they cause loin pain, urinary tract infection, renal colic, pyuria, haematuria or hypertension [ 3, 5].

Ultrasound suggests the diagnosis in a high percentage of cases. The presence of mobile calculi or milk of calcium within the cyst are characteristic and very common [2, 3] and may also be identified in the abdominal plain film. When these findings are absent, PCD may be indistinguishable from simple cyst and Intravenous urography (IVU) or CT may be helpful. On IVU, most pyelocaliceal diverticula will show a delayed opacification owing to the retrograde filling from the connection with the collecting system [4]. However, if the neck of a PCD is obstructed, the diverticulum will not opacify and it is impossible to distinguish it from a simple renal cyst [3].

PCDs are usually small and asymptomatic, and treatment is usually not necessary[1, 4]. In patients with symptomatic radiopaque caliceal diverticular stones, percutaneous nephrolithotomy is the standard procedure.
Differential Diagnosis List
Stone-containing caliceal diverticulum.
Complex renal cyst
Haemorrhagic renal cyst
Infected renal cyst
Final Diagnosis
Stone-containing caliceal diverticulum.
Case information
DOI: 10.1594/EURORAD/CASE.9959
ISSN: 1563-4086