Radiology-Pathology Conference: Mature teratoma arising from an intra-abdominal undescended testis in a 7-month-old infant.

We report a rare case of an intra-abdominal testicular mature teratoma in a 7-month-old male infant presenting with a palpable abdominal mass and unilateral undescended testis. We describe the pathology, clinical presentation, and imaging findings of this entity. Clinical features accompanied by characteristic radiologic findings guide a provisional diagnosis that is confirmed by histologic analysis following surgical removal of the tumor. The pathogenesis and radiologic findings of testicular mature teratomas in the prepubertal population share many similarities to that of mature ovarian teratomas commonly seen in females of reproductive age. Awareness of this entity will permit the radiologist to suggest timely diagnosis and intervention when presented with a similar case.