Mesoblastic nephroma


This is a case of a pathology-confirmed congenital mesoblastic nephroma of mixed subtype. diagnosed at the age of six months. In our case, the imaging features could not help with the differentiating between the Wilms tumor and mesoblastic nephroma, but because of the patient age Wilms tumor was less likely.

Summary of the surgical report:

Left kidney mass weighing 730 g excised completely. The mass was well encapsulated with smooth borders. Capsule not violated during dissection. Dense adhesions into the posterior and superior borders of the retroperitoneum.

Summary of the pathology report:

Congenital mesoblastic nephroma of mixed subtype.  Although most of the neoplasm corresponds to cellular morphology, focal areas with the classical component are noted. Focal penetration of the renal capsule with extension into the perinephric soft tissue is noted supporting a local stage of II. Surgical margins and submitted lymph nodes are free of neoplasm, and no nephrogenic rests are appreciated.