Prepubertal Testicular Teratomas and Epidermoid Cysts: Comparison of Clinical and Sonographic Features

To evaluate clinical and sonographic features of testicular teratomas and epidermoid cysts in children and to assess differential points of immature teratomas from benign counterparts.

We retrospectively reviewed testicular teratomas and epidermoid cysts in children. Age at surgery, α-fetoprotein (AFP) level, and sonographic findings, including components (mainly cystic, mainly solid, or mixed), presence of calcification, and size, were reviewed.

Nineteen cases were included, with 10 mature teratomas, 3 immature teratomas, and 6 epidermoid cysts. On sonography, most of the teratomas (n = 9) had mixed components, with 2 mainly cystic and 2 mainly solid lesions. The 2 mainly cystic teratomas underwent follow-up sonography and showed component changes to mainly solid. Compared to epidermoid cysts, teratomas were larger (P = .029) with less cystic components (P = .046). All 3 immature teratomas showed mixed components with calcification. In differentiating immature from benign teratomas, immature teratomas were larger (P= .047) in younger children (P= .008) with higher AFP levels (P= .023). The optimal cutoff values for diagnosing immature teratomas were 8 months of age, 23 ng/mL in AFP level, and 2.5 cm in size, with 100% sensitivity and 89.5% accuracy rates. However, sonographic features, including tumor components and presence of calcification, were not helpful for differentiating immature teratomas.

Testicular masses in children younger than 8 months with AFP levels higher than 23 ng/mL and size larger than 2.5 cm need to be considered for orchiectomy rather than testis-sparing tumorectomy because of the increased frequency of immature teratomas versus mature teratomas or epidermoid cysts.