Elsevier

Human Pathology

Volume 40, Issue 3, March 2009, Pages 418-424
Human Pathology

Case study
Adult extrarenal Wilms tumor of the uterus with teratoid features

https://doi.org/10.1016/j.humpath.2008.05.020Get rights and content

Summary

The present article reports for the first time a case of an extrarenal teratoid Wilms tumor in the uterus of a 62-year-old woman. It had triphasic histology with epithelial areas composed of metanephric tubules harboring glomerular structures, adamantine patterns, neural type rosettes, blastema, and a primitive, myxoid type stroma. Abundant heterologous elements such as cartilage, striated muscle, squamous epithelium, and an alpha fetoprotein and TTF1-positive early endodermal epithelium were also present. Immunohistochemistry in Wilms tumor areas showed positivity for markers also indicative of peripheral primitive neuroectodermal tumors such as neuron-specific enolase, CD99, and CD56. However, nuclear positivity for Wilms tumor antigen together with the presence of glomeruli and the absence of endometrioid tumor areas and the organoid arrangement of tissues excluded peripheral primitive neuroectodermal tumors, carcinosarcoma, and teratoma, respectively. Although the diagnosis of female genital tract Wilms tumors is difficult in cases where glomerular structures are lacking, it should be considered because these neoplasms have a better therapeutic response than peripheral primitive neuroectodermal tumors and carcinosarcoma.

Section snippets

Case report

This nulliparous 62-year-old woman had an episode of profuse vaginal bleeding. She was referred to a regional hospital where she was seen to have a large uterine hemorrhagic polypoid mass protruding through the cervix. Surgery revealed an enlarged globular uterus without pelvic adhesions or ascites, and a total abdominal hysterectomy with salpingo-oophorectomy was performed. An initial histopathologic diagnosis of peripheral primitive neuroectodermal tumor (pPNET) was considered. The case was

Materials and methods

Tissues from 18 samples of tumor were fixed in 10% neutral buffered formalin and paraffin embedded. Five-microgram-thick sections were stained with hematoxylin and eosin. Immunohistochemical studies with an avidin-biotin peroxidase complex method used antibodies directed against the following: CD56 (Master Diagnostica [MD], Granada, Spain; monoclonal 56C04, diluted), CD57 -Leu-7- (MD, monoclonal HNK-1, diluted, CD99 MD, monoclonal 013 diluted), neu-n (Chemicon International, Temecula, CA, USA;

Pathology findings

Macroscopically, the uterus revealed an 8-cm sessile, friable, hemorrhagic mass in its fundus that protruded into the endometrial cavity and filled the cervical canal but on cut section was seen to invade only superficially a markedly dilated and thinned myometrium. The adnexa were involutive but otherwise unremarkable.

Microscopically, myometrial invasion was reduced to 3 mm. No areas of endometrioid differentiation were seen other than the normal endometrial glands embedded within the

Discussion

Extrarenal WTs are unusual neoplasms occurring preferentially in children, and they usually involve lumbosacral areas, retroperitoneum, and other midline locations [3], [7], being rare in the testis and adnexa. Most of them are pure tumors with only a small fraction originating from teratoma or germ cell neoplasms.

The female genital tract is nevertheless the second most frequent location, with 19 cases documented to date, 13 of which were found in the uterus, 4 in the ovary, and 2 in the cervix

Acknowledgment

The authors would like to thank Dr T González-Rocha for her assistance.

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