# Diagnosis, treatment, and long-term follow-up of a 13-year-old boy with a testicular mixed germ cell tumor (yolk sac tumor and embryonal carcinoma): a case report and literature review

**Authors:** Jing Yang, Jianjun Lai, Shiping Zheng, Huanmei Tang

PMC · DOI: 10.3389/fped.2026.1793767 · 2026-03-17

## TL;DR

A 13-year-old boy with a rare testicular tumor combining yolk sac tumor and embryonal carcinoma was successfully treated with surgery and remained cancer-free for 29 months.

## Contribution

This is the first documented case of a mixed yolk sac tumor and embryonal carcinoma in a 13-year-old boy with long-term follow-up data.

## Key findings

- The patient had elevated alpha-fetoprotein and human chorionic gonadotropin levels, typical of germ cell tumors.
- Radical orchiectomy led to no recurrence or metastasis over 29 months of follow-up.
- The case highlights the importance of timely diagnosis and treatment in adolescent testicular tumors.

## Abstract

Testicular germ cell tumors (TGCTs) are rare in children under 15 years of age. We report the first documented case of a mixed yolk sac tumor and embryonal carcinoma in the left testis of a 13-year-old boy in the early stages of puberty (12–14 years). The patient presented with a left scrotal mass, markedly elevated serum alpha-fetoprotein and human chorionic gonadotropin levels, and ultrasonographic findings suggestive of a testicular tumor. Pathological confirmation was obtained after radical orchiectomy, with no recurrence or metastasis observed during 29 months of follow-up. This case report reviews the literature on histologically similar testicular tumors and summarizes diagnostic and management experiences. For testicular mixed germ cell tumors in early adolescence, immediate radical orchiectomy can achieve clinical cure, and long-term follow-up is crucial.

## Linked entities

- **Diseases:** yolk sac tumor (MONDO:0002143), embryonal carcinoma (MONDO:0003581)

## Full-text entities

- **Genes:** AFP (alpha fetoprotein) [NCBI Gene 174] {aka AFPD, FETA, HPAFP}
- **Diseases:** embryonal carcinoma (MESH:D018236), testicular tumor (MESH:D013736), scrotal mass (MESH:C536030), TGCTs (MESH:C563236), yolk sac tumor (MESH:D018240)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

2 figures with captions in the complete paper: https://tomesphere.com/paper/PMC13036159/full.md

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Source: https://tomesphere.com/paper/PMC13036159