# Yolk Sac Tumour of the Testis

> Yolk sac tumour of testis for NEET-PG Surgery: AFP marker, Schiller-Duval bodies, paediatric versus adult behaviour, orchidectomy and BEP outcomes.

- Canonical URL: https://prepelephant.com/topics/neet-pg/surgery/yolk-sac-tumour-testis
- Exam / course: NEET-PG · Subject: Surgery
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-02
- Last updated: 2026-10-02
- How to cite: "Yolk Sac Tumour of the Testis", PrepElephant, https://prepelephant.com/topics/neet-pg/surgery/yolk-sac-tumour-testis

## Direct answer

The yolk sac tumour (endodermal sinus tumour) is the most common testicular tumour of childhood, typically presenting as a painless scrotal mass in a boy under five years. It secretes alpha-fetoprotein (AFP), and Schiller-Duval bodies (papillary structures resembling a glomerulus) are its histological signature. In children the tumour is usually pure, behaves less aggressively than its adult counterpart, and inguinal radical orchidectomy alone cures most stage I disease; in adults it almost always appears as a component of a mixed nonseminomatous germ cell tumour and is treated on NSGCT protocols.

## What you must remember

- Commonest testicular tumour in prepubertal children; commonest infant testicular tumour overall is a teratoma-yolk sac spectrum lesion.
- AFP is the tumour marker; interpret with age, because AFP is physiologically raised in infants and may not normalise until 8-12 months of age.
- Schiller-Duval bodies are pathognomonic on histology; reticular/microcystic and solid patterns also occur.
- Paediatric yolk sac tumour spreads haematogenously early, especially to the lungs, unlike the lymphatic-first spread of adult postpubertal tumours.
- Inguinal radical orchidectomy is the operation; a transscrotal approach violates tumour boundaries and alters lymphatic drainage.
- Stage I in a child: orchidectomy plus close surveillance; salvage chemotherapy (BEP) rescues the few who relapse, keeping five-year survival above 95 per cent.
- In adults, a raised AFP with a testicular mass means nonseminomatous mixed germ cell tumour until proved otherwise, whatever the dominant histology.

## A typical exam case walks through cleanly

A two-year-old is brought with a three-week painless, hard swelling of the right testis that does not transilluminate. The steps the examiner expects: first, scrotal ultrasound showing a solid intratesticular lesion; second, serum AFP sent before surgery (never after orchidectomy alone, and interpreted against age-specific infant ranges); third, radical orchidectomy through a groin incision with early clamping of the spermatic cord; fourth, staging CT of chest and abdomen — in children, CT chest matters because haematogenous lung spread dominates, and bone scan only if symptomatic.

If histology shows pure yolk sac tumour with clear margins and imaging is clean, the child is clinical stage I. Standard care is surveillance with serial AFP and chest imaging rather than routine adjuvant chemotherapy, since relapses are almost always salvaged with cisplatin-based chemotherapy. Metastatic disease gets BEP (bleomycin, etoposide, cisplatin); in very young children etoposide-cisplatin combinations are adapted by paediatric oncology protocols to limit lung and ototoxicity. The examinable nuance is the contrast with the adult patient, where the same histology inside a mixed tumour demands full NSGCT staging with AFP, beta-hCG and LDH, abdominal CT for retroperitoneal nodes, and consideration of surveillance, one cycle of BEP, or primary retroperitoneal lymph node dissection for clinical stage I disease.

## Where students slip

Two traps recur. The first is the infant with a normal AFP being called "marker-negative" — physiologically elevated AFP in a baby under about one year cannot exclude yolk sac tumour, and the viva answer is "use age-normalised reference ranges". The second is assuming a raised AFP proves yolk sac histology in an adult; any germ cell tumour except pure seminoma and pure choriocarcinoma can produce AFP, and hepatocellular disease is the classic non-malignant cause examiners add to the stem. Remembering that the marker reflects tumour biology, not the microscope, prevents both errors.

## Frequently asked questions

### Which tumour marker is characteristic of yolk sac tumour?
Alpha-fetoprotein, produced by the yolk sac endoderm. It is used for diagnosis, staging, monitoring response (half-life about five to seven days), and surveillance after orchidectomy.

### What are Schiller-Duval bodies?
Papillary, glomerulus-like structures with a central blood vessel, seen histologically in yolk sac tumour. They are considered pathognomonic and are a one-mark favourite in pathology viva.

### What is the most common testicular tumour in a child?
Yolk sac tumour in its pure form, within the prepubertal teratoma-yolk sac spectrum; in adolescents and adults the balance shifts to mixed germ cell tumours and seminoma.

### How does stage I yolk sac tumour in a child be managed?
Inguinal radical orchidectomy followed by close surveillance with AFP and imaging. Adjuvant chemotherapy is not routine because relapse is rare and salvageable.

### Why does yolk sac tumour in children spread differently from adult germ cell tumours?
Prepubertal yolk sac tumour favours early haematogenous spread to the lungs, whereas postpubertal tumours spread first to the retroperitoneal lymph nodes, which is why staging emphasis differs.