An 11-Year-Old Boy with a Painless Scrotal Mass and a Normal AFP
An 11-year-old boy presents with a firm, painless right scrotal swelling noticed 2 months ago. Examination shows a 3 cm intrascrotal mass that does not transilluminate and is separate from the epididymis; the testis is palpable but the mass seems to involve the testis. He is otherwise well, with no virilization, no gynecomastia, and no abdominal mass. Scrotal ultrasound shows a solid, heterogeneous intratesticular mass with internal vascularity and no calcifications. Serum AFP is normal; beta-hCG is normal; LDH is mildly elevated. A chest radiograph is normal. The family is anxious and asks whether the testis can be saved and whether he needs chemotherapy.
1. What is the differential diagnosis in this age group, and how do the tumor markers shift your thinking?
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In a prepubertal boy, an intratesticular solid mass is most often a prepubertal-type teratoma or a yolk sac tumor; sex cord-stromal tumors (juvenile granulosa cell tumor, Leydig cell tumor, Sertoli cell tumor) are also considerations, and lymphoma/leukemia is rare but possible.
Marker interpretation:
- Normal AFP makes a pure yolk sac tumor unlikely but does not exclude a mixed germ cell tumor or a teratoma. Yolk sac tumor is the most common malignant prepubertal germ cell tumor and usually elevates AFP.
- Normal beta-hCG argues against choriocarcinoma and against most mixed tumors with trophoblastic elements.
- Mildly elevated LDH is nonspecific and can reflect tumor burden or turnover; it does not establish malignancy.
- No virilization or gynecomastia makes a functioning Leydig or Sertoli tumor less likely, though nonfunctioning sex cord tumors occur.
The key point: in prepubertal boys, teratomas are generally benign (prepubertal-type) and can sometimes be managed with testis-sparing surgery, whereas postpubertal-type teratomas and yolk sac tumors are malignant. Age and histology drive management more than markers alone.
2. Describe your surgical approach and the intraoperative decisions that determine whether the testis is preserved.
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Approach: radical inguinal orchiectomy is the standard for a suspected malignant intratesticular mass in a child, but testis-sparing surgery is increasingly considered for small, well-circumscribed lesions with normal markers, especially when the contralateral testis is abnormal or the lesion is benign-appearing.
Intraoperative decision-making:
- Inguinal exploration with early control of the spermatic cord (tourniquet or vascular clamp) to allow a bloodless field if testis-sparing is attempted.
- Frozen section of the lesion. If frozen section shows a benign prepubertal teratoma or a benign sex cord tumor, partial orchiectomy with negative margins can preserve the testis.
- If frozen section is indeterminate or malignant, proceed to radical orchiectomy with high ligation of the cord.
- Do not violate the scrotum if malignancy is suspected, to avoid altering lymphatic drainage.
Factors favoring testis-sparing: small size, normal markers, well-defined lesion, normal contralateral testis, and a center with frozen-section capability. Factors favoring orchiectomy: large or ill-defined mass, elevated markers, suspicion of yolk sac or mixed germ cell tumor.
3. Assuming final pathology shows a pure prepubertal-type teratoma with negative margins, what is the surveillance plan and what would change if it were a yolk sac tumor?
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Pure prepubertal-type teratoma, completely excised: generally benign behavior in this age group. Surveillance with clinical exam, scrotal ultrasound, and tumor markers (AFP, beta-hCG) at intervals (e.g., every 3-6 months for the first 2 years, then annually) is reasonable; no chemotherapy or retroperitoneal lymph node dissection is indicated. If orchiectomy was performed, the focus is on contralateral testis surveillance and testosterone/fertility counseling as he grows.
If it were a yolk sac tumor:
- Staging evaluation including chest imaging (already normal) and consideration of retroperitoneal imaging.
- Chemotherapy (platinum-based, e.g., bleomycin/etoposide/cisplatin or a pediatric regimen) is generally indicated for yolk sac tumor, even with normal markers post-orchiectomy, because of its chemosensitivity and risk of micrometastasis.
- RPLND is not routine in children; chemotherapy is the mainstay for metastatic or high-risk disease.
- AFP becomes the key surveillance marker; rising AFP after orchiectomy suggests residual or metastatic disease.
The contrast is the teaching point: histology, not the imaging appearance, determines whether this child gets chemotherapy.