Transcript Complex renal Cysts - eLearning

SIMPLE AND COMPLEX RENAL CYSTS
By:
Nour-Eldin A Nour-Eldin
SIMPLE CYSTS
 Simple cysts (in > 50% of
population > 50 years) probably
arise from obstructed tubules
or ducts.
 They do not, however,
communicate with collecting
system.
 Most commonly
asymptomatic; rare: hematuria
(from cyst rupture), HTN,cyst
infection. Mass effect from
large cysts may cause dull ache
or discomfort.
Radiographic features , IVP:
Lucent defect
"Beak sign" can be
seen with large cysts.
Round indentations on
collecting system
Cortical bulge
Radiographic features , US:
Anechoic
Sharply marginated,
smooth walls
Enhanced through-transmission
Radiographic features , CT:
No significant enhancement
after IV contrast (<5HU)
Smooth cyst wall
Sharp demarcation
Cyst wall too thin to be seen by CT
Homogenous Water
density (< 10-15 HU)
Be Careful:
Cysts that contain calcium,
septations, and irregular margins
(complicated cysts)
need further workup
True renal cysts should always be
differentiated from
hydronephrosis, calyceal
diverticulum, and peripelvic cysts.
Differentiate renal cyst from
hypoechoic renal artery aneurysm
using color Doppler US and
Angiography
Hydronephrosis:
Parapelvic Cyst
Calyceal Diverticulum
Renal Artery Aneurysm
Complicated CYSTS
Complicated cysts are
cysts that do not meet
the criteria of simple
cysts and thus require
further workup.
Bosniak Classification:
Category (Bosniak)
US Features
Workup
Type 1: Simple cyst
Round, anechoic, thin wall
enhanced through
transmission
Type 2: Mildly complicated
cyst
Thin septation, calcium in
wall
CT or US follow-up
Type 3: Indeterminate
lesion
Multiple septae, internal
echos mural nodules
Partial nephrectomy,
biopsy
Thick septae
CT follow-up if surgery is
high risk
Type 4: Clearly malignant
Solid mass component
None
Nephrectomy
Radiographic Features of Complicated Cysts
Septations
Thin septa within cysts are usually benign.
Thick or irregular septa require workup.
Calcifications
Thin calcifications in cyst walls are usually benign.
Milk of calcium: collection of small calcific granules in cyst fluid:
usually benign
Increased CT density (> 15 HU) of cyst content
Vast majority of these lesions are benign.
High density is usually due to hemorrhage, high protein content,
and/or calcium.
Thick wall
These lesions usually require surgical exploration.
Simple renal cyst, Bosniak Category I.
Bosniak Category II cyst
Curvilinear calcification within a thin septum
Bosniak Category II cyst
Homogeneously hyperdense mass
No increase in Density after IV contrast
Bosniak Category II cyst
Cyst with several internal
septations and a minimally
thickened wall
Bosniak Category II cyst.
Cyst with uniform, mild wall thickening and
short, interrupted calcifications
Bosniak Category II hyperdense cyst.
Bosniak Category II cyst
Bosniak Category II cyst.
Nearly completely calcified mass with no obvious
enhancing elements
Bosniak Category II.
subcentimeter rim calcified renal cyst
Bosniak Category III.
cystic mass with irregular wall thickening and
associated heterogeneous nonenhancing elements
Bosniak Category III complex cyst.
multilocular, encapsulated mass
Bosniak Category III complex cyst.
Thick-walled, encapsulated,
multilocular cystic mass with
enhancing septa
Bosniak
Category IV
cystic
neoplasm.
Bosniak Category IV cystic neoplasm
A 42-year-old female with back pain, hematuria, and a
renal mass discovered by lumbar spine MR.
hyperdense (55 HU)
3 cm mass.
enhance to 88 HU after IV contrast
Renal cell carcinoma
Thank
you
Thank
you