SN7 SHORT NOTE 5M

Classify testicular tumours. Differentiate seminoma from non-seminomatous germ cell tumours.

Pathology · 2nd Professional — Para-Clinical

Definition and Classification

Testicular tumours are the commonest solid malignancy in young men aged 15 to 35. Over 95% are germ cell in origin.

Group	Tumours	Share
Germ cell — seminomatous	Seminoma (classical, anaplastic, spermatocytic)	About 50%
Germ cell — non-seminomatous	Embryonal carcinoma, yolk sac tumour, choriocarcinoma, teratoma, and mixed tumours (the commonest single category)	About 45%
Sex cord–stromal	LEYDIG cell tumour (may secrete androgens or oestrogens, causing precocious puberty or gynaecomastia); sertoli cell tumour	Under 5%
Other	Lymphoma — the commonest testicular tumour in men over 60	—

Risk factors — cryptorchidism (a 3 to 5 fold increase, and the risk applies to both testes), previous testicular tumour, family history, testicular dysgenesis, Klinefelter syndrome (mediastinal germ cell tumours), HIV
Orchidopexy reduces but does not abolish the risk, and makes the testis examinable — which is itself valuable

Seminoma and Non-seminoma Compared

Feature	Seminoma	Non-seminomatous
Peak age	30–40	20–30
Naked eye	Homogeneous, lobulated, potato-like, grey-white; NO haemorrhage or necrosis	Variegated with haemorrhage, necrosis and cysts
Microscopy	Sheets of uniform cells with clear cytoplasm and central nuclei, in a fibrous stroma with a lymphocytic infiltrate and sometimes granulomas	Varies with the component
AFP	Never raised	Raised with a yolk sac component
HCG	Mildly raised in about 15%	Markedly raised in choriocarcinoma
Spread	Lymphatic, to para-aortic nodes; remains localised longer	Earlier haematogenous spread, especially choriocarcinoma
Radiosensitivity	Exquisitely radiosensitive	Relatively radioresistant; chemosensitive
Prognosis	Excellent — over 95%	Good, but less so

CLINICAL PEARL

A raised AFP means the tumour is not a pure seminoma, whatever the histology says. Seminomas do not produce alpha-fetoprotein. If it is raised, there is a non-seminomatous element somewhere that the sections have missed, and the patient is treated as non-seminomatous. This is one of the few situations in oncology where a blood test overrides the pathologist.

Lymphatic Drainage and Spread

The testis descends from the posterior abdominal wall, taking its blood supply and lymphatic drainage with it
Lymph therefore drains to the para-aortic nodes at the level of L2, not to the inguinal nodes
The scrotal skin drains to the inguinal nodes — so a scrotal incision for a suspected tumour risks seeding a new lymphatic field, which is why orchidectomy is performed through an inguinal approach with early cord clamping
Haematogenous spread to lung, liver, brain and bone

Applied Aspects

Presents as a painless, firm, hard testicular swelling that does not transilluminate; about 10% present with pain and may be mistaken for epididymo-orchitis
Ultrasound of the scrotum is highly sensitive; markers (AFP, hCG, LDH) are measured before and after orchidectomy, and their rate of fall guides further treatment
Never biopsy a testicular tumour transcrotally — inguinal orchidectomy is both diagnostic and therapeutic
Sperm banking must be offered before treatment, since these are young men with a high chance of cure and treatment impairs fertility
Among the most curable of all cancers, with over 90% cure even with metastatic disease, because of exquisite sensitivity to platinum-based chemotherapy
Late effects of cure matter — second malignancy, cardiovascular disease, infertility and hypogonadism; lifelong follow-up is warranted in men cured in their twenties

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