Diagnostic ultrasound ( PDFDrive )

346 PART II Abdominal and Pelvic Sonography
Transitional Cell Carcinoma
Transitional cell carcinoma (TCC) of the renal pelvis accounts
for 7% of all primary renal tumors. 182 Renal TCC is two to three
times more common than ureteral neoplasms. Bladder TCC,
because of its large surface area, is 50 times more common than
renal pelvic TCC. 183 he multifocal and bilateral nature of TCC
requires accurate diagnosis and staging to allow appropriate
surgical planning. Yousem et al. 184 reviewed 645 cases of TCC
of the bladder, ureter, and kidney and found that 3.9% of patients
with bladder cancer developed an upper tract lesion (mean,
within 61 months); 13% of patients with ureteral TCC and 11%
of those with renal TCC developed metachronous tumors (mean,
within 28 and 22 months, respectively). Synchronous TCC was
present in 2% of patients with bladder TCC, 39% with ureteral
TCC, and 24% with renal TCC. Upper tract disease surveillance
may be performed by retrograde pyelography, urine cytology,
CT urography, and/or magnetic resonance urography. 185
TCCs may be papillary or nonpapillary. Papillary TCCs are
exophytic polypoid lesions attached to the mucosa by a stalk.
his type of tumor tends to be lower grade at presentation;
polypoid TCC typically iniltrates slowly and metastasizes late
in the disease. Nonpapillary, sessile TCCs present as nodular
or lat tumors; the mucosal thickening that is a hallmark of
sessile TCC may be diicult to depict even at CT. hese tumors
are usually high grade and iniltrating. 183
Renal Tumors
Transitional cell tumors of the kidney are more common in men
than women (4 : 1). Renal TCC is typically seen in older patients;
the mean age at diagnosis is 65 years. 183 About 75% of patients
with renal pelvic tumors present with gross or microscopic
hematuria; 25% have lank pain. Renal TCC is discovered
incidentally in less than 5% of patients. 183
Unfortunately, the sonographic assessment of the renal sinus
poses unique problems and is a challenge to evaluate for pathologic
processes because of its variable appearance. Fat within the renal
sinus can appear as a hypoechoic mass and can simulate a solid
TCC (Fig. 9.53). In uncertain cases, conirmation with CT
A
B
C
FIG. 9.53 Renal Sinus Fat Mimicking Transitional
Cell Carcinoma (TCC). Sagittal sonograms in two patients.
(A) Small focal area of hypoechogenicity is seen within
echogenic sinus fat in the lower pole. (B) Color Doppler
image at the same level as A shows normal vessels
running through this area, conirming insigniicant fat rather
than tumor. (C) Hypoechoic central renal sinus fat mimics
iniltrating TCC. A normal renal sinus was shown at
conirmatory CT.