Dedifferentiated Cystic Nephroma with Malignant Mesenchymoma as the Dedifferentiated Component

Abstract

Cystic tumors of the kidney are uncommon and usually do not have solid areas. We report a predominantly cystic renal tumor with solid anaplastic component showing rhabdomyoblastic and cartilaginous differentiation in a 26-month-old girl. Terminology and pathogenesis of tumor progression are discussed along with a review of reports of tumors associated with cystic nephroma.

Key Words:

• cystic nephroma
• malignant mesenchymoma
• tumor dedifferentiation
• Wilms’ tumor