38 Urinary Bladder
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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.
C67.0 Trigone of bladder C67.1 Dome of bladder C67.2 Lateral wall of
bladder C67.3 Anterior wall of
bladder
C67.4 Posterior wall of bladder C67.5 Bladder neck C67.6 Ureteric orifice C67.7 Urachus
C67.8 Overlapping lesion of bladder
C67.9 Bladder, NOS
INTRODUCTION
Bladder cancer is one of the most common malignancies in Western society, and it occurs more commonly in males. Predisposing factors include smoking, expo- sure to chemicals, such as phenacetin and dyes, and schistosomiasis. It has also been suggested that the incidence of this disease correlates inversely with fluid intake. Hematuria is the most common presenting feature. Bladder cancer can present as a low-grade papillary lesion, as an in situ lesion that can occupy large areas of the mucosal surface, or as an infiltrative cancer that rapidly extends through the bladder wall and can thereafter metastasize. The papillary and in situ lesions may be associated with a malignant course, with sudden invasion of the bladder wall. The most common histologic variant is urothelial (transitional cell) carcinomas, although this may exhibit features of glandular or squamous differentiation. In less than 10% of cases, pure adenocarcinoma or squamous carcinoma of the bladder may occur, and less frequently, sarcoma, lymphoma, small cell anaplastic carcinoma, pheochromocytoma, choriocarcinoma. Squa- mous carcinoma is associated with schistosomiasis and smoking.
ANATOMY
Primary Site. The anatomic sites and subsites of the urinary bladder are illus- trated in Figure 38.1. The urinary bladder consists of three layers: the epithe- lium and the subepithelial connective tissue, the muscularis, and the perivesical fat (peritoneum covering the superior surface and upper part). In the male, the bladder adjoins the rectum and seminal vesicle posteriorly, the prostate inferi- orly, and the pubis and peritoneum anteriorly. In the female, the vagina is located posteriorly and the uterus superiorly. The bladder is located extraperitoneally.
Regional Lymph Nodes. The regional lymph nodes are the nodes of the true
pelvis (Figure 38.2), which essentially are the pelvic nodes below the bifurcation
of the common iliac arteries. The significance of regional lymph node metasta-
sis in staging bladder cancer lies in the number and size, not in whether metas-
tasis is unilateral or contralateral. One of the major prognostic determinants of
ultimate cure is whether the tumor is confined to the bladder, and a major adverse prognostic feature is the presence of any lymph nodal metastases.
Regional nodes include:
Hypogastric Obturator
Urachus (C67.7) Dome (C67.1)
Lateral wall (C67.2) Anterior wall (C67.3) Ureteric orifice (C67.6) Bladder neck (C67.5)
Prostate (C61.9) Posterior wall (C67.4)
FIGURE 38.1. Anatomical sites and subsites of the urinary bladder.
C77.5
FIGURE 38.2. Regional lymph nodes of the urinary bladder.
Iliac (internal, external, NOS) Perivesical
Pelvic, NOS
Sacral (lateral, sacral promontory [Gerota’s]) Presacral
The common iliac nodes are considered sites of distant metastasis and should be coded as M1.
Metastatic Sites. Distant spread is most commonly to lymph nodes, lung, bone, and liver.
DEFINITIONS Primary Tumor (T)
TX Primary tumor cannot be assessed T0 No evidence of primary tumor
Ta Noninvasive papillary carcinoma (Figure 38.3) Tis Carcinoma in situ: “flat tumor” (Figure 38.3)
T1 Tumor invades subepithelial connective tissue (Figure 38.3) T2 Tumor invades muscle (Figure 38.3)
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1 Epithelium
2 Subepithelial connective tissue 3 Muscle
4 Perivesical fat
1 2 3 4
Tis T1 T2a
1/2
T2b T3a
T3b T4a T4b Ta
FIGURE 38.3. Illustration of the definitions of primary tumor (T) for primary
bladder cancer, ranging from Ta to T4.
pT2a Tumor invades superficial muscle (inner half) pT2b Tumor invades deep muscle (outer half) T3 Tumor invades perivesical tissue (Figure 38.3) pT3a Microscopically
pT3b Macroscopically (extravesical mass)
T4 Tumor invades any of the following: prostate, uterus, vagina, pelvic wall, abdominal wall
T4a Tumor invades prostate, uterus, vagina (Figure 38.3) T4b Tumor invades pelvic wall, abdominal wall (Figure 38.3)
Regional Lymph Nodes (N)
NX Regional lymph nodes cannot be assessed N0 No regional lymph node metastasis
Nl Metastasis in a single lymph node, 2 cm or less in greatest dimension (Figure 38.4)
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 38.5A, B)
N3 Metastasis in a lymph node, more than 5 cm in greatest dimension (Figures 38.6A, B)
Distant Metastasis (M)
MX Distant metastasis cannot be assessed M0 No distant metastasis
M1 Distant metastasis
£2 cm N1
FIGURE 38.4. N1 is defined as metastasis in a single lymph node, 2 cm or less in
greatest dimension.
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>2-5 cm N2
A
£5 cm N2
B
FIGURE 38.5. A. N2 is defined as 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 is defined as metastasis
in a single lymph node, more than 2 cm but not more than 5 cm in greatest
dimension, or multiple lymph nodes, as illustrated, none more than 5 cm in
greatest dimension.
>5 cm N3
A
>5 cm N3