Extrarenal Wilms' tumour

Pediatric Extra-Renal Nephroblastoma (Wilms' Tumor): A Systematic Case-Based Review

Wilms Tumor (WT) is one of the most common renal tumors in the pediatric population. Occasionally, WT can primarily develop outside the kidneys (Extra-Renal Wilms Tumor, ERWT). Most pediatric ERWTs develop in the abdominal cavity and pelvis, whereas the occurrence of this tumor in other extra-renal sites represents a minor part of ERWT cases. In addition to describing a case of spinal ERWT (associated with spinal dysraphism) in a 4-year boy (to add a further clinical experience on this very rare pediatric tumor), we performed a case-based systematic literature review on pediatric ERWT. We retrieved 72 papers providing enough information on the diagnosis, treatment, and outcomes of 98 ERWT pediatric patients. Our research highlighted that a multimodal approach involving both chemotherapy and radiotherapy, after partial or complete tumor resection in most cases, was typically used, but there is no standardized therapeutic approach for this pediatric malignancy. However, this tumor may be potentially treated with a better success rate if the diagnostic confirmation is not delayed, the mass can be totally resected, and an appropriate and, possibly, tailored multimodal treatment can be promptly established. In this regard, an international agreement on a unique staging system for (pediatric) ERWT is definitely needed, as well as the development of international research, which may be able to gather several children diagnosed with ERWT and, possibly, lead to clinical trials which should also include developing countries.

Tumor de Wilms extra-renal: relato de caso

Um caso de tumor de Wilms extra-renal de localização retroperitoneal em uma paciente do sexo feminino de dois anos de idade é apresentado, associado a revisão de literatura. Foram realizados exames de radiografia simples do abdome, urografia excretora, ultra-sonografia e tomografia computadorizada sem e com contraste, que evidenciaram a presença de massa retroperitoneal adjacente ao rim direito. A paciente foi submetida a intervenção cirúrgica, com ressecção de toda a massa, sendo o diagnóstico de tumor de Wilms confirmado com exame anatomopatológico. O tumor de Wilms extra-renal é uma entidade extremamente rara e maligna, descrito na literatura principalmente sob a forma de relato de caso. Pode ocorrer no retroperitônio, útero e ovários, canal inguinal, testículos, pele, e até mesmo no tórax. O mecanismo exato que poderia explicar a ocorrência deste tumor em tecido extra-renal não foi bem estabelecido ainda. O diagnóstico é feito através do estudo anatomopatológico da lesão, geralmente após intervenção cirúrgica.

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.

Association of extrarenal Wilms' tumor with a horseshoe kidney

Nephroblastoma (Wilms' tumor) is the most common renal malignancy in childhood. Extrarenal Wilms' tumor is uncommon, and the diagnosis is almost always postsurgical. The authors report two cases, located in the sigmoid mesocolon, one of these having an associated horseshoe kidney. Both were treated with excision followed by chemotherapy. They are now 36 months and 7 months postchemotherapy, respectively, and are symptom and recurrence free. Both had favorable histological findings. Association with a horseshoe kidney raises an important issue regarding the histogenesis of these tumors. The authors believe that there is a nexus between the fusion of metanephric blastema during the sixth to seventh week of intrauterine life and the "ectopic" metanephric blastema cells that may give rise to extrarenal Wilms' tumor. Association with a horseshoe kidney with an extrarenal Wilms' tumor has been reported on five previous occasions. The authors closely examine the link between the two.

Renal neoplasms of childhood

Wilms' tumor is the most common childhood renal tumor. This article describes the epidemiology, histopathologic features, and clinical manifestations of Wilms' tumor along with the spectrum of imaging findings using different modalities. The distinguishing features of other renal tumors encountered in children, such as clear cell sarcoma, rhabdoid tumor, congenital mesoblastic nephroma, multilocular cystic renal tumor, renal cell carcinoma, and angiomyolipoma are also reviewed.

A unique dysembryonic neoplasm of the adrenal gland composed of nephrogenic rests in a child

A primary neoplasm of the right adrenal gland in a 4-year-old boy was discovered after the patient developed bowel obstruction following an appendectomy. Until the histologic examination, the tumor was thought to be a neuroblastoma. However, the intra-adrenal tumor was composed of blastematous nodules, primitive tubules, and glomeruloid structures whose overall composition resembled a Wilms' tumor. Other than a single focus of mucinous glands, the tumor lacked the range of somatic tissue types of a teratoma. Approximately 50 cases of putative extrarenal Wilms' tumor have been reported. The retroperitoneum is one of the more common primary sites, yet our case is the first documented example of a neoplasm with features of a Wilms' tumor arising in the adrenal. Based on the embryologic and anatomic relationship between the adrenal gland and kidney, it is somewhat surprising that other instances of similar appearing tumors have not been described before the present case. Our patient was managed on a Wilms' tumor protocol and remains tumor free 15 months after surgery.