From the Guidelines
The most common types of testicular tumors in infants, from most to least common, are yolk sac tumors, teratomas, juvenile granulosa cell tumors, and gonadoblastomas. These types of tumors are distinct from those found in adolescents and adults, where seminomas and non-seminomatous germ cell tumors are more prevalent 1. The prevalence of these tumor types in infants is as follows:
- Yolk sac tumors account for approximately 70-80% of all testicular tumors in infants and young children, making them the most prevalent 1.
- Teratomas are the second most common, comprising about 15% of pediatric testicular tumors and containing tissue from multiple germ layers 1.
- Juvenile granulosa cell tumors are rare sex cord-stromal tumors that typically present in the first year of life 1.
- Gonadoblastomas are even less common and are often associated with disorders of sexual development 1. It's essential to note that the distribution of these tumor types differs significantly from adolescents and adults, reflecting the distinct developmental biology and hormonal environment of the infant testis compared to the post-pubertal testis 1. Some key points to consider when evaluating testicular tumors in infants include:
- The importance of serum tumor markers, such as alpha-fetoprotein (AFP), in diagnosing and monitoring treatment response 1.
- The role of testicular ultrasound in confirming the presence of a testicular mass and exploring the contralateral testis 1.
- The need for prompt evaluation and treatment, as testicular tumors can be aggressive and require timely intervention 1.
From the Research
Testicular Tumors in Infants
The most common types of testicular tumors in infants, listed from most to least common, are:
- Teratomas: comprising 48% of the tumors, with mature teratomas being the most common subtype 2
- Yolk sac tumors: accounting for 15% of the tumors, and being the most common malignant testicular tumor in children 3, 2
- Epidermoid cysts: found in 14% of patients, and considered to be tumor-like lesions of unknown etiology 4, 2
- Gonadal stromal cell tumors: representing 13% of the total, divided among granulosa cell, Leydig cell, Sertoli cell, and mixed gonadal stromal cell tumors 2
- Other pathology: including cystic dysplasia, lymphoma, inflammatory pseudotumor, and gonadoblastoma, making up 9% of the total number of cases 2
Key Findings
- Benign lesions represent the majority of primary testis tumors (74%) in infants and young children 2
- Yolk sac tumor is a tumor with a favorable prognosis, with a survival rate of 91.6% at 7 years after diagnosis 5
- Serum alpha-fetoprotein (AFP) concentration is extremely useful in diagnosis and monitoring of treatment response for yolk sac tumors 3, 5