Prepubertal testicular teratomas and epidermoid cysts: Comparison of clinical and sonographic features

Objectives - 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. Methods - 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. Results - 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. Conclusions - 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.