37 Renal Pelvis and Ureter
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SUMMARY OF CHANGES
• The definitions of TNM and the Stage Grouping for this chapter have not changed from the Fifth Edition.
C65.9 Renal pelvis C66.9 Ureter
INTRODUCTION
Urothelial (transitional cell) carcinoma may occur at any site within the upper urinary collecting system from the renal calyx to the ureterovesical junction. The tumors occur most commonly in adults and are rare before 40 years of age.
There is a two- to threefold increase in incidence in men compared with women.
The lesions are often multiple and are more common in patients with a history of urothelial carcinoma of the bladder. A number of analgesics (such as phenacetin) have also been associated with this disease. Local staging depends on the depth of invasion. A common staging system is used regardless of tumor location within the upper urinary collecting system, except for category T3, which differs between the pelvis or calyceal system and the ureter.
ANATOMY
Primary Site. The renal pelvis and the ureter form a single unit that is con- tinuous with the collecting ducts of the renal pyramids and comprises the minor and major calyces, which are continuous with the renal pelvis. The ureteropelvic junction is variable in position and location but serves as a “landmark” that sep- arates the renal pelvis and the ureter, which continues caudad and traverses the wall of the urinary bladder as the intramural ureter opening in the trigone of the bladder at the ureteral orifice. The renal pelvis and the ureter are composed of the following layers: epithelium, subepithelial connective tissue, and muscu- laris, which is continuous with a connective tissue adventitial layer. It is in this outer layer that the major blood supply and lymphatics are found.
The intrarenal portion of the renal pelvis is surrounded by renal parenchyma, and the extrarenal pelvis by perihilar fat. The ureter courses through the retroperitoneum adjacent to the parietal peritoneum and rests on the retroperitoneal musculature above the pelvic vessels. As it crosses the vessels and enters the deep pelvis, the ureter is surrounded by pelvic fat until it trav- erses the bladder wall.
Regional Lymph Nodes. The regional lymph nodes for the renal pelvis are:
Renal hilar Paracaval Aortic
Retroperitoneal, NOS
The regional lymph nodes for the ureter are:
Renal hilar
Iliac (common, internal [hypogastric], external) Paracaval
Periureteral Pelvic, NOS
Any amount of regional lymph node metastasis is a poor prognostic finding and outcome is minimally influenced by the number, size, or location of the regional nodes that are involved.
Metastatic Sites. Distant spread is most commonly to the lung, bone, or liver.
DEFINITIONS Primary Tumor (T)
TX Primary tumor cannot be assessed T0 No evidence of primary tumor
Ta Papillary noninvasive carcinoma (Figure 37.1) Tis Carcinoma in situ
T1 Tumor invades subepithelial connective tissue (Figure 37.1) T2 Tumor invades the muscularis (Figure 37.2)
T3 (For renal pelvis only) Tumor invades beyond muscularis into peripelvic fat or the renal parenchyma (Figure 37.2)
T3 (For ureter only) Tumor invades beyond muscularis into periureteric fat T4 Tumor invades adjacent organs, or through the kidney into the perinephric
fat (Figures 37.3A–C)
Ta T1 T2
Epthelium
Subepithelial connective tissue
Muscularis
Periureteric fat Peripelvic fat
FIGURE 37.1. Ta is defined as papillary noninvasive carcinoma; T1 is defined as tumor invading subepithelial connective tissue; T2 is defined as tumor invading the muscularis.
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T3
T3
FIGURE 37.2. T3 (for renal pelvis only, top of diagram): tumor invades beyond muscularis into peripelvic fat or the renal parenchyma. T3 (for ureter only, bottom of diagram): tumor invades beyond muscularis into periureteric fat.
T4
Vertebral body
A
FIGURE 37.3. A. T4 tumor invades adjacent organs, or through the kidney into the perinephric fat. Here, the tumor invades the vertebral body.
T4 T4
B
T4
Perinephric fat Gerota fascia
C
FIGURE 37.3. B. T4 tumor (ureter) invades adjacent organs. On the left, tumor invades the iliac vessels. On the right, tumor invades the bladder. C. T4 tumor invades through the kidney into the perinephric fat.
N1
£2 cm
FIGURE 37.4. N1 is defined as metastasis in a single lymph node, 2 cm or less in greatest dimension.
Regional Lymph Nodes (N)
NX Regional lymph nodes cannot be assessed N0 No regional lymph node metastasis
N1 Metastasis in a single lymph node, 2 cm or less in greatest dimension (Figure 37.4)
N2 Metastasis in a single lymph node, more than 2 cm but not more than 5 cm in greatest dimension; or multiple lymph nodes, none more than 5 cm in greatest dimension (Figures 37.5A, B)
N3 Metastasis in a lymph node, more than 5 cm in greatest dimension (Figures 37.6A, B)
Distant Metastasis (M)
MX Distant metastasis cannot be assessed M0 No distant metastasis
M1 Distant metastasis
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N2
>2-5 cm
A
N2
£5 cm
B
FIGURE 37.5. A. N2 nodal metastasis in a single lymph node, more than 2 cm but not more than 5 cm in greatest dimension, as illustrated; or multiple lymph nodes, none more than 5 cm in greatest dimension B. N2 nodal metastasis in a single lymph node, more than 2 cm but not more than 5 cm in greatest dimension; or multiple lymph nodes, none more than 5 cm in greatest dimension, as illustrated.
N3
>5 cm
A
N3
>5 cm
B
FIGURE 37.6. A. N3 is defined as metastasis in a lymph node, more than 5 cm in greatest dimension. B. N3 nodal metastasis in a lymph node, more than 5 cm in greatest dimension. As illustrated here, multiple lymph nodes are involved with one nodal mass exceeding 5 cm.
STAGE GROUPING
0a Ta N0 M0
0is Tis N0 M0
I T1 N0 M0
II T2 N0 M0
III T3 N0 M0
IV T4 N0 M0
Any T Nl M0
Any T N2 M0
Any T N3 M0
Any T Any N M1
