The large pediatric scrotum: ultrasound technique and differential considerations.

Scrotal enlargement in the pediatric population is caused by a variety of pathologic processes including hydroceles, hernias, varicoceles, testicular torsion, testicular or paratesticular infection, trauma, or neoplasm; adrenal rests; or scrotal skin edema. The clinical presentation of scrotal enlargement is often nonspecific, and ultrasound plays a key role in making the correct diagnosis. In this pictorial review, we review the ultrasound protocol for performing scrotal ultrasound in pediatric patients and illustrate the ultrasound appearance of conditions resulting in scrotal enlargement.

Medulloblastoma: seeding of VP shunt tract and peritoneum.

We report on a 5-year-old boy with seeding of the peritoneum and a ventriculoperitoneal shunt tract by anaplastic medulloblastoma. The role of ventriculoperitoneal shunting in the spread of primary central nervous system tumors has been controversial. In the case reported here, the unique distribution of tumor implants on ultrasound and multiplanar computed tomography gives further credence to the argument that ventriculoperitoneal shunting is a pathway for extraneural metastases of primary central nervous system tumors.

Wilms' tumor arising within a mediastinal teratoma.

The majority of Wilms' tumors present in young children as an intraabdominal mass of renal origin. The use of multimodal treatment protocols according to internationally recognized treatment guidelines has resulted in extremely high cure rates even in the setting of advanced disease. By comparison, Wilms' tumors in older patients or Wilms' tumors located entirely outside the kidney are extremely rare. Because of the rarity of these tumors and the lack of established treatment guidelines specific to these lesions, older patients with atypical Wilms' tumors are at risk for under treatment and poorer outcomes. We report the case of an 18-year-old man with a Wilms' tumor arising within a mediastinal teratoma and discuss the management of this extremely rare lesion.