An extrarenal Wilms' tumour arising from an undescended testis

Extrarenal Anaplastic Wilms Tumor: A Case Report With Genomic Analysis and Tumor Models

Primary extrarenal Wilms tumors are rare neoplasms that are presumed to arise from metanephric or mesonephric remnants outside of the kidney. Their pathogenesis is debated but has not been studied, and there are no reports of genomic descriptions of extrarenal Wilms tumors. We describe a diffusely anaplastic extrarenal Wilms tumor that occurred in the lower abdomen and upper pelvis of a 10-year-old boy. In addition to the clinical, histopathologic, and radiologic features, we describe the cytogenetic changes and exomic profile of the tumor. The tumor showed loss of the tumor suppressor AMER1, loss of chromosome regions 1p, 16q, and 22q, gain of chromosome 8, and loss of function TP53 mutation-findings known to occur in renal Wilms tumors. This is the first description of the exomic profile of a primary extrarenal Wilms tumor. Our data indicate that primary extrarenal Wilms tumors may follow the same pathogenetic pathways that are seen in renal Wilms tumors. Finally, we describe the establishment of first ever tumor models (primary cell line and patient-derived xenograft) from an extrarenal Wilms tumor.

Extrarenal teratoid wilms' tumor in association with horseshoe kidney

Extrarenal teratoid Wilms' tumor is a rare variant of Wilms' tumor. Literature shows only 17 reported cases. We present this right-sided teratoid Wilms' tumor in a 3-year-old boy for its rarity in association with the horseshoe kidney. The tumor was found in the anterior aspect of the right kidney and consisted of triphasic Wilms' tumor element along with the presence of heterologous components.

Teratoma with somatic-type malignant components of the testis. A review and an update

Malignant transformation of germ cell tumors into somatic malignancy is uncommon. Its presentation differs from series to series, with 43 % of adult cases identified within the primary tumors and the remainder at the time of relapse or in the metastasis. Patients with stage I disease enjoy an excellent prognosis; whereas in metastatic sites when not completely resectable, the somatic type malignancies suffer a dismal prognosis. Radical surgery is significant for the prospects of cure and is standard chemotherapy for germ cell tumors; a transformation-oriented treatment can be effective for these patients. A deeper understanding of the biology of this phenomenon is essential for clinicians involved in such malignancies in order to permit a better control of the disease.

Extrarenal Wilms tumor in children with unfavorable histology: a case report

Extrarenal Wilms tumor is extremely rare, and only 25 cases in children have been reported to date in Japan. A 2-year-old girl presented with a large left lower quadrant abdominal mass. Abdominal computed tomography revealed a retroperitoneal tumor located below the left kidney. At laparotomy, the tumor was encapsulated without evidence of metastasis to other abdominal organs. Pathologic diagnosis of the tumor was extrarenal Wilms tumor with diffuse anaplasia. After complete tumor resection, chemotherapy was administered according to the treatment protocol (Regimen I) of the Japan Wilms Tumor Study Group. Cyclophosphamide and etoposide were administered in combination with vincristine and doxorubicin. Two years after treatment, the patient has had no evidence of recurrence.

Extra-renal Wilms' tumour--is it different?

Nephroblastomas (Wilms' tumour) are the most common solid malignancies in childhood, but extra-renal Wilms' tumours are rare entities, and the diagnosis is made only after surgical intervention. However, the embryogenesis and the exact mechanism of occurrence of primary ERWTs is controversial, thereby presenting a number of unanswered questions of great theoretical interests. We present three well-proven cases of extra-renal Wilms' tumour together with a review of the literature based on its histogenesis, its behaviour and its management policies.

Nephroblastic Neoplasms

Nephroblastoma, or Wilms tumor, is a malignant embryonal neoplasm that is derived from nephrogenic blastemal cells, with variable recapitulation of renal embryogenesis. The pathogenesis of nephroblastoma is complex and has been linked to alterations of several genomic loci, including WT1, WT2, FWT1, and FWT2. Generally, nephroblastoma is composed of variable proportions of blastema, epithelium, and stroma, each of which may exhibit a wide spectrum of morphologic variations. Distinguishing nephroblastoma with favorable histology from tumors that exhibit anaplasia is an integral component of histologic assessment because of its prognostic and therapeutic implications. Nephrogenic rests and a special variant of nephroblastoma, cystic partially differentiated nephroblastoma, also are discussed.

Wilms' tumor of the ovary: A case report

The occurrence of true extrarenal Wilms' tumor is extremely rare. The most frequently noted extrarenal sites are the retroperitoneal and inguinal regions. In the female genital tract, the occurrence of Wilms' tumor has been documented in the uterus, endocervix, and ovary in isolated case reports. In this article the authors describe a case of ovarian Wilms' tumor in a 3.5-year-old girl. Her abdominal ultrasound scan and computed tomography scan showed a solid mass with cystic components on the left lower quadrant. Total excision was performed with left salpingo-oophorectomy. There was no other mass and also no evidence of metastasis. To the best of the authors' knowledge, this patient is the first reported case of primary ovarian Wilms' tumor arising in childhood.

Wilms' tumor of the cervix: a case report and review of the literature

INTRODUCTION

Extrarenal Wilms' tumors are rare, with only 55 well-documented cases in the literature and only 4 confined to the uterus. A fifth case along with review of the current literature is presented.

CASE

A 13-year-old girl presented with a 2-month history of irregular vaginal spotting. A 6.5 x 4.5 x 2.5-cm polypoid mass meeting criteria for an extrarenal Wilms tumor was removed from the superior aspect of the cervix, but recurred 8 months later on the posterior lip. The patient underwent a Schauta procedure, lymph node dissection, and bilateral oophoropexy. The surgery was followed by typical renal Wilms' tumor chemotherapy. The patient is without evidence of disease 5 years after surgery.

DISCUSSION

This case uniquely suggests that limited excision of the original tumor has inherent risks for relapse. Oophoropexy appears to be reasonable when fertility preservation is desired and reconfirms that treatment mimicking renal nephroblastomas offers good long-term survival.

Unique dermal and subcutaneous botryoid rhabdomyosarcoma associated with mature renal tissue: is this an extrarenal Wilms' tumor?

A unique dermal and subcutaneous botryoid rhabdomyosarcoma admixed with ectopic mature renal tissue, overlying the left lateral lumbosacral region of a 41/2-year-old girl is reported. The tumor was devoid of blastemal or immature epithelial elements and nephrogenic rests. The relationship of this lesion to an extrarenal Wilms' tumor with exclusive myogenous differentiation is discussed.

Extrarenal Wilms' tumor: results of the National Wilms' Tumor Study

Extrarenal Wilms' tumor is extremely rare and occurs predominantly in children. Eight cases of extrarenal Wilms' tumor were reported to the National Wilms' Tumor Study from 1980 to 1986. Patients were followed in the study and not randomized to a particular treatment protocol. Seven patients had a favorable histology. One tumor located in the sacrococcygeal region showed immature teratoma with nephroblastic tissue. The embryogenesis of extrarenal Wilms' tumor is controversial; however, tumor containing teratomatous elements most likely represents a different embryologic origin and, therefore, should be classified separately. All eight patients were treated with operative excision and chemotherapy. Seven of the eight patients were disease-free with a mean follow-up of 34.3 months. It can be inferred from this small group of patients that the prognosis is comparable to intrarenal Wilms' tumor in the National Wilms' Tumor Study.

Extrarenal Wilms tumor occurring in the inguinal canal

We report an unusual case of extrarenal Wilms tumor discovered incidentally during routine inguinal orchiopexy. The world literature and embryological implications of Wilms tumor in the inguinal canal are reviewed.

Pronephros and mesonephros--Cohnheim revisited

Erroneous quotations in the literature and Cohnheim's statement, in his Lectures on General Pathology, that the Wolffian body or mesonephros is the first anlage of the urogenital system prompted this description of the growth of our knowledge of the early development of the kidney. Some of the pertinent older literature is reviewed, and the concept of the holonephros, as opposed to the trinephric view of kidney development, is discussed. Emphasis is placed on the decreasing functional significance of the pronephros with evolutionary development, to the extent that the role of the pronephros in the human is questioned. Cohnheim's seemingly erroneous reference to the development of the kidney is shown to be merely a reflection of the views current at his time.

Primary extrarenal Wilms' tumor in children

We report three additional cases of primary extrarenal Wilms' tumor and review those cases previously documented. Analysis of the location, histopathology, treatment, and survival of these cases supports the following conclusions: Wilms' tumor may occur in an extrarenal location without primary renal involvement and must be included in the differential diagnosis of abdominal, pelvic, and inguinal masses; an extrarenal location supports a more frequent occurrence of ectopic metanephric blastema than was previously recognized or origin of Wilms' tumor from a more primitive mesodermal tissue; and the natural history and prognosis of extrarenal and renal Wilms' tumors appears similar.

Extrarenal nephroblastomas

The cases of extrarenal nephroblastoma published in the world literature have been tabulated and reviewed, and are discussed from a historical point of view.

Extrarenal Wilms' tumor: an analysis of four cases

During a review of Wilms' tumor, four located external to the kidney were identified. Patient age ranged from 7 months to 4 years; three were female. One neoplasm was located in the parametrial connective tissue to the left of the uterus; both kidneys were radiographically normal. Three neoplasms were located in the right retroperitoneum adherent to the surface of the ipsilateral kidney, but separated from the parenchyma by a thick fibrous capsule. Two were attached to the upper pole, while the third was attached to the midportion of the kidney. Radiologic studies showed displacement of all three kidneys, but intravenous pyelogram (IVP) revealed no calyceal distortion. All four neoplasms were favorable histology Wilms' tumor: one was monophasic epithelial type, one was monophasic blastemal type, and two had a mixture of stromal, epithelial, and blastemal tissue. No teratomatous elements were present. Immunoperoxidase staining for cytokeratin (AE-1, AE-3, CAM 5.2), vimentin, and epithelial membrane antigen (EMA) showed the strongest focal positive staining of tubular structures with CAM 5.2, and slight staining with EMA. Staining reaction to vimentin was variable, but negative in most areas. Three tumors extracted from paraffin were diploid by quantitative flow cytometric DNA analysis; in one case, flow cytometry could not be performed. Clinical follow-up from 2 years to 6 years showed all children to be alive without evidence of disease. Based on the similarity to conventional renal Wilms' tumor, these findings support the hypothesis of displaced mesonephric/metanephric rests for the origin of extrarenal Wilms' tumor.

Extrarenal Wilms' tumor

The extrarenal location of Wilms' tumor is extremely rare. These tumors can arise from other neoplasms, generally teratomas, or they can present without any associated teratomatous elements. We encountered only 19 well-documented cases of isolated extrarenal nephroblastoma, and we describe three previously unreported patients with this disease. Two of the three children presented also with horseshoe kidneys, an association that may have clinical and embryologic significance. The presence of tumor cephalad to a horseshoe kidney is easier to explain when we consider that they originate from primitive mesodermal tissue, probably mesonephric rests, and not from metanephric remnants. Also, this association should alert physicians to the possible diagnosis of extrarenal nephroblastoma in patients with a retroperitoneal mass and horseshoe kidneys. These patients should be treated according to the same protocols as those for patients with intrarenal Wilms' tumor.

Extrarenal Wilms' tumor

A rare case of retroperitoneal extrarenal Wilms' tumor with an unusual presentation is reported. The tumor contained a large cystic component and mimicked ascites clinically.

Primary ovarian Wilms' tumor

A case of extrarenal Wilms' tumor presenting as an ovarian mass in a woman 56 years of age is described. Histologically, glomeruloid and tubular structures were identified within nests of undifferentiated epithelium. No teratomatous components were encountered. A review of the literature found three other reports of Wilms' tumor occurring in the female genital tract. This case represents the oldest patient with extrarenal Wilms' tumor in the literature.