Diagnostic Ultrasound - Abdomen and Pelvis

Multilocular Cystic Nephroma
Diagnoses: Urinary Tract
TERMINOLOGY
• Rare nonhereditary benign cystic renal neoplasm
containing epithelial and stromal components
IMAGING
• Encapsulated multilocular cystic renal mass herniating into
renal hilum
• Grayscale ultrasound
○ Numerous anechoic cysts with hyperechoic septa
○ Occasionally more solid-appearing due to numerous tiny
cysts causing acoustic interfaces
• Fine vessels may be seen within septa on color Doppler
• Contrast uptake within septa and wall on CEUS
• CT: Large, well-defined multiloculated cystic mass, ±
calcification, ± capsular enhancement
• T1WI: Multiloculated hypointense mass (clear fluid) with
variable signal intensity (blood or protein)
KEY FACTS
TOP DIFFERENTIAL DIAGNOSES
• Cystic renal cell carcinoma (RCC)
• Mixed epithelial and stromal tumor (MEST)
• Cystic Wilms tumor
CLINICAL ISSUES
• Present with hematuria, abdominal/flank pain, palpable
mass
• Complications
○ Obstructive uropathy, infection, hemorrhage
• Cured with complete surgical excisionblane
• Bimodal age and sex distribution: 2-4 years old, M>F; 40-60
years old, F>>M
DIAGNOSTIC CHECKLIST
• Appears as Bosniak class 3 or 4 cystic mass
• May be indistinguishable from cystic renal carcinoma
• Presence of enclosing capsule distinguishes MLCN from
almost all other cystic renal masses
(Left) Longitudinal view of the
right kidney reveals numerous
small anechoic cystic locules
ſt in the lower pole,
separated by echogenic septa,
comprising a MLCN. This
herniates into the renal hilum
st, with associated
obstruction of the renal pelvis
leading to upper pole
calyectasis . (Right) Coronal
T2-weighted MR in the same
patient demonstrates multiple
hyperintense cystic locules ſt
surrounded by a well-defined
hypointense fibrous capsule
.
(Left) Longitudinal ultrasound
view of the left kidney reveals
multiple large anechoic cysts
in the lower pole ſt separated
by thick septae , consistent
with MLCN. The upper pole
cystic structure represents
calyceal dilatation secondary
to mass effect from the MLCN.
(Right) Coronal contrastenhanced
CT image in the
same patient showing multiple
large cystic locules ſt in the
lower pole, surrounded by a
thick fibrous capsule . Mass
effect leads to calyceal
dilatation in the upper pole
.
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