300 CHAPTER 6 Urological neoplasia
Testicular cancer: pathology and staging
Ninety percent of testicular tumors are malignant germ cell tumors (GCT), split into seminomatous and non-seminomatous (NS) GCTs for clinical purposes. Seminoma, the most common germ cell tumor, appears pale and homogeneous. NSGCTs are heterogeneous and sometimes contain bizarre tissues such as cartilage or hair.
Metastases to the testis are rare, notably from the prostate (35%), lung (19%), colon (9%), and kidney (7%). Table 6.15 shows the WHO histopathological classification of testicular tumors.
The right testis is affected slightly more commonly than the left; synchronous bilateral TC occurs in 2% of cases. TC spreads by local extension into the epididymis, spermatic cord, and, rarely, the scrotal wall.
Lymphatic spread occurs via the testicular vessels, initially to the paraaortic nodes. Involvement of the epididymis, spermatic cord, or scrotum may lead to pelvic and inguinal node metastasis.
Blood-borne metastasis to the lungs, liver, and bones is more likely once the disease has breached the tunica albuginea.
TC is staged using various classifications, most recently the TNM (2002) system (see Fig. 6.9 and Table 6.16). Here, T stage is pathological, N stage involves imaging, and M stage involves physical examination, imaging, and biochemical investigations. An additional S category is appended for serum tumor markers (see p. 305).
Table 6.15 WHO histopathological classification of testicular tumors
Germ cell tumors (90%)
Seminoma (48%)
•Spermatocytic, classical, and anaplastic subtypes
Non-seminomatous GCT (42%)
•Teratoma
•Differentiated/mature
•Intermediate/immature
•Undifferentiated/malignant
•Yolk sac tumor
•Choriocarcinoma
•Mixed NSGCT
Mixed GCT (10%)
Other tumors (7%)
•Epidermoid cyst (benign)
•Adenomatoid tumor
•Adenocarcinoma of the rete testis
•Carcinoid
•Lymphoma (5%)
•Metastatic, from another site (1%)
Sex cord stromal tumors (3%) (10% malignant)
•Leydig cell
•Sertoli cell
•Mixed or unclassified
Mixed germ cell/sex cord tumors (rare)
TESTICULAR CANCER: PATHOLOGY AND STAGING 301
(a)
Vas deferens, spermatic cord
Scrotal wall
Epididymis
Tunica vaginalis
(b)
T1−4
T1 |
T2 |
Testis
T3 |
T4 |
N0 M0 |
T1−4 N1−3 M0 |
T1−4 N1−3 M1
Figure 6.9 Pathological staging of testicular cancer. (a) Primary tumors T1–T4. If radical orchiectomy has not been used, Tx is used. (b) Node/metastasis: para-aortic lymphadenopathy, measured in long axis on CT scan (upper figures); supraclavicular lymphadenopathy and/or pulmonary metastases—M1a, other distant metastases (e.g., liver, brain)—M1b (lower figure).
302 CHAPTER 6 Urological neoplasia
Table 6.16 TNM staging of testicular germ cell tumors. S staging is presented on p. 305
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Tx |
The primary tumor has not been assessed (no radical orchiectomy) |
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T0 |
No evidence of primary tumor |
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Tis |
Intratubular germ cell neoplasia (carcinoma in situ) |
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T1 |
Tumor limited to testis and epididymis without vascular invasion; |
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may invade tunica albuginea but not tunica vaginalis |
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T2 |
Tumor limited to testis and epididymis with vascular/lymphatic |
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invasion, or tumor involving tunica vaginalis |
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T3 |
Tumor invades spermatic cord with or without vascular invasion |
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T4 |
Tumor invades scrotum with or without vascular invasion |
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Nx |
Regional lymph nodes cannot be assessed |
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N0 |
No regional lymph node metastasis |
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N1 |
Metastasis with a lymph node d2 cm or multiple lymph nodes, |
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none >2 cm |
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N2 |
Metastasis with a lymph node size 2–5 cm or multiple lymph nodes, |
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collected size 2–5 cm |
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N3 |
Metastasis with a lymph node mass >5 cm |
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Mx |
Distant metastasis cannot be assessed |
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M0 |
No distant metastasis |
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M1a |
Nonregional lymph node or pulmonary metastasis |
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M1b |
Distant metastasis other than to nonregional lymph node or lungs |
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TESTICULAR CANCER 303
Testicular cancer: prognostic staging system for metastatic germ cell cancer
The International Germ Cell Cancer Collaborative Group (IGCCCG) has devised a prognostic factor–based staging system for metastatic germ cell cancer that includes goodand intermediate-prognosis seminoma and good-, intermediate-, and poor-prognosis non-seminomatous germ cell tumors (NSGCT) (Table 6.17).
See p. 299 for discussion on testicular tumor markers, including S staging (p. 305). Primary therapy of testicular cancer is based on the following:
•Histology (seminoma vs. NSGCT)
•Clinical TNM stage.
•International Germ Cell Cancer Collaborative Group (IGCCCG) classification (good, intermediate, or poor risk)
Table 6.17 IGCCCG staging system for metastatic germ cell cancer
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Seminoma |
NSGCT |
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Good |
90% of patients |
56% of patients |
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5-year progression- |
86% |
92% |
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free survival |
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Testis or retroperitoneal primary |
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All factors listed |
Any primary site; |
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present: |
no nonpulmonary |
site; no nonpulmonary visceral |
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visceral metastases; |
metastases; AFP <1000 ng/mL; |
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normal AFP; any |
hCG <5000 mIU/L; and LDH <1.5 |
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hCG or LDH |
normal upper limit (S1) |
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Intermediate |
10% of patients |
28% of patients |
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5-year progression- |
73% |
80% |
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free survival |
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Testis or retroperitoneal primary |
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All factors listed |
Any primary site; |
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present: |
nonpulmonary |
site; no nonpulmonary visceral |
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visceral metastases |
metastases; AFP 1000–9999 ng/mL |
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present; normal AFP; |
or hCG 5000–49999 mIU/mL; LDH |
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Any hCG or LDH |
1.5–10 normal upper limit (S2) |
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Poor |
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16% of patients |
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5-year progression- |
No patients classified |
48% |
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free survival |
as poor prognosis |
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All factors listed |
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Mediastinal primary; nonpulmonary |
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present: |
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visceral metastases present; AFP |
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>10,000 ng/mL or hCG >50,000 |
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mIU/L; LDH >10 normal upper |
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limit (S3) |
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