Mesoblastic nephroma is a distinctive pathologic renal
tumor with unique clinical, therapeutic, and prognostic patterns. This report reviews 51 patients (2.8% of 1905 patients submitted to NWTS with renal
tumors) with this diagnosis from the NWTS contrasting this disease entity with
Wilms' tumor. There were 33 males and 18 females, predominantly term babies born after uncomplicated pregnancies. The mean age at
tumor excision was 3.44 +/- 0.6 mo (one child 9 yr). A palpable mass was the predominant presentation in 48 patients and in addition
hematuria (9),
hypertension (2),
vomiting (3), and
jaundice (1) were noteworthy. Diagnostic studies included IVP (49 positive, 2 negative) and ultrasound (15 positive, 1 negative). Adequate operative excision was achieved in 43 of 51 patients while 8 children had local extension and 10 had
tumor spillage. Operation alone (23), predominantly since 1978, surgery plus
chemotherapy (24), prior to 1978, and surgery,
chemotherapy, and
radiation therapy (4), prior to 1976, were the modes of
therapy. The follow-up ranges from 4 mo to 11.5 yr. Survival was excellent; 50 patients survive (98%), only 1 dying of
sepsis. These data suggest that
mesoblastic nephroma contrasts with
Wilms' tumor in that it occurs in a younger age group, has a benign
biologic behavior, and a more favorable outcome. Aggressive
multimodal treatment though utilized in the early years of the study is not essential to achieve this outcome.