History :
This 4+ y/o boy was suffered from abdominal distension for 2 months
with recent URI symptom.
Image finding :
CT revealed a huge (10-13 cm) heterogeneous,capsulated,no active
bleeding,no calcification,mild splitting over dependent part mass
originated from L't kidney and thrombus noted in both L't renal
V. and IVC, no extension was noted up to hepatic V. The contralateral
kidney was WNL. Some LAP(+) noted along IVC intra-abdominally.
Diagnosis :
Huge renal mass over L't kidney R/O Wilms tumor
Discussion :
WILMS =nephroblastoma
Most common malignant abdominal neoplasm in children 1-8 years old
(10%)!
3rd most common malignancy in childhood (after leukemia + brain
tumors; neuroblastoma more common in infancy)!
3rd most common of all renal masses in childhood (after hydronephrosis
+ multicystic dysplastic kidney)!
Incidence:
-1:10,000 livebirths; 450 cases/year in USA; familial in 1-2%; multifocal
in 10%; bilateral in 4.4-9%
Age:
peak age at 2.5-3 years (range of 3 months to 8 years); rare during
first year; 50% before 3 years, 75% before 5 years; 90% before 8
years; rare in adults; M:F = 1:1
Stage:
-I tumor limited to kidney
-II local extension into perirenal tissue / renal vessels outside
kidney / lymph nodes
-III not totally resectable (peritoneal implants, other than paraaortic
nodes involved, invasion of vital structures)
-IV hematogenous metastases (lung, liver, bone [rare], brain)
-V bilateral renal involvement at diagnosis (5-10%)
-palpable abdominal mass (90%)
-hypertension (47-90%)
-abdominal pain (25%)
-fever (15%)
-gross hematuria (7-15%)
-microscopic hematuria (15-20%)
-large tumor (average size 12 cm)
-sharply marginated with compressed renal tissue = pseudocapsule
partially cystic = focal hemorrhage and necrosis (71%)
-curvilinear / phlebolithic calcifications in 5% on plain film,
in 15% on CT (DDx: regular stippled calcifications in neuroblastoma)
-distorted "clobbered" calices
-tumor may invade IVC / right atrium (4-10%)
-tumor may cross midline
-hypervascular tumor: enlarged tortuous vessels, coarse neovascularity;
small arterial aneurysms, vascular
-parasitization of vascular supply
US:
fairly evenly echogenic mass ± irregular anechoic areas due to central
necrosis +
MR:
hypointense on T1WI, variable on T2WI |
