Secondary Logo

Journal Logo

Institutional members access full text with Ovid®

TeratoidWilms Tumor

The Extreme End of Heterologous Element Differentiation, Not a Separate Entity

D’Hooghe, Ellen MD*; Mifsud, William MD, PhD, FRCPath; Vujanić, Gordan M. MD, PhD, FRCPath†,‡

The American Journal of Surgical Pathology: November 2019 - Volume 43 - Issue 11 - p 1583–1590
doi: 10.1097/PAS.0000000000001335
Original Articles

Wilms tumor (WT) may show a diverse range of heterologous elements (HEs). Cases with predominant/prominent HEs have been reported as “teratoid” WT, albeit on the basis of poorly defined criteria. It has been suggested that “teratoid” WTs are rare, and associated with a poor response to chemotherapy, but a good outcome. However, these claims have not been tested previously in any large cohort of cases. Here, we performed a systematic study to determine the incidence, diversity, and clinicopathologic association of HEs in 691 WTs, all of which were treated according to the same protocol, which included preoperative chemotherapy, and all with central pathology review. We found that 4% (28/691) of WTs showed ≥3 HEs (“teratoid” WT in our study), which was comparable to the numbers of completely necrotic, epithelial, focal anaplastic, and blastemal WTs. “Teratoid” WTs were strongly associated with younger age at presentation (21 vs. 39 mo, P=0.0001), bilateral disease (28.6% vs. 7.2%, P=0.001), stromal-type WT (57.1% vs. 11.0%, P<0.00001), and intralobar nephrogenic rests (35.7% vs. 11.9%, P=0.0001), when compared with non-“teratoid” WT. We also found that stromal-type WT, regardless of HE differentiation, was itself associated with younger age, bilateral disease, and intralobar nephrogenic rest. Furthermore, >80% of cases with ≥3 HEs, and also of cases with 2 HEs and 1 HE, showed ≥50% stroma in their viable components. We conclude that a tendency toward stromal differentiation is a strong and unifying factor in HE formation. “Teratoid” WT represents the more extreme end of HE differentiation, rather than a separate entity, and therefore the term should not be used in the final diagnosis. The prognosis of WTs depends only on their overall histologic type and stage, and it is not additionally influenced by the presence of “teratoid” features.

*Department of Pathology, Oslo University Hospital, Rikshospitalet, Oslo, Norway

Department of Pathology, Sidra Medicine, Doha, Qatar

Department of Cellular Pathology, School of Medicine Cardiff University, Cardiff, United Kingdom

E.D’H., W.M., and G.M.V.: cofirst authors and contributed equally.

Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article.

Correspondence: Gordan M. Vujanić, MD, PhD, FRCPath, Department of Pathology, Sidra Medicine, H2M Pathology Room 2MF 140, Al Luqta Street, Doha, Qatar (e-mail:

Online date: July 25, 2019

Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.