Diagnosis and imaging characteristics of a juvenile fibroadenoma in a 2-year-old patient: a case report.

Fibroadenomas are abundantly reported in the literature with several papers documenting the natural progression and clinical outcomes of thousands of cases. Juvenile fibroadenomas (also called cellular fibroadenomas) are frequently characterized by rapid growth, often described as 5-10 cm in size. They constitute approximately 7%-8% of fibroadenomas. They often measure greater than 5 cm. Pathologically, they show similar features to fibroadenomas but can resemble phyllodes. There have been few documented cases of breast masses in early childhood. Furthermore, there are scant radiology publications focused on the imaging features of juvenile fibroadenomas in patients younger than 5 years old. Our patient presented at 2 years of age with a unilateral right breast mass. Two ultrasound examinations were completed over a period of 5 months, and a magnetic resonance imaging was performed prior to surgical intervention. Eventual surgical excision yielded a final pathologic diagnosis of juvenile fibroadenoma. In this report, we will discuss the imaging and pathology of juvenile fibroadenomas, and we will address important differential considerations both from a pathologic and radiologic standpoint.