Extrarenal Wilms' tumor

Case report: The CT features of pediatric retroperitoneal extrarenal Wilms tumor: a report of two cases and literature review

Retroperitoneal extrarenal Wilms tumor is a rare condition in children that can be easily misdiagnosed as other retroperitoneal malignancies unrelated to the renal origin. Computerized tomography scan plays a crucial role in diagnosing and distinguishing retroperitoneal malignancies. In this report, we present two cases of retroperitoneal extrarenal Wilms tumor in children who were admitted due to abdominal mass. Laboratory examination did not reveal any significant abnormality. However, a computerized tomography scan revealed a solid or cystic-solid mass in the retroperitoneum accompanied by a bone spur extending from the anterior edge of the vertebral body to the back of the mass, while the origin of the tumor remained unclear. By analyzing these two cases and reviewing previous studies on retroperitoneal extrarenal Wilms tumor in children, we summarized the clinical and imaging characteristics of this rare condition. We also found that the presence of a spinal deformity adjacent to the mass might indicate the possibility of a retroperitoneal extrarenal Wilms tumor.

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.

Extrarenal Nephroblastoma of the Retroperitoneal Space in Children: A Case Report and Review of the Literature

Extrarenal nephroblastoma (ERNB) is a rare disease. We report a case of ERNB in a 4-year-old boy complaining of abdominal pain and vomiting. Imaging showed a retroperitoneal mass and left hydronephrosis. The mass was completely removed by surgery. The pathologic diagnosis was ERNB with favorable histology. Postoperative chemotherapy was administered for 24 weeks with actinomycin D, vincristine, and doxorubicin. No signs of recurrence were found for the next 3 years. We consider 53 reports of ERNB and our own. Median age at diagnosis was 42 months. The most common site is the retroperitoneal space (44.4%), followed by the uterus (14.8%).

Pelvic Wilms tumor in a child with an absent right kidney and spinal malformations

Wilms tumor rarely occurs in other sites outside the kidney. Various congenital malformations often accompany Wilms tumor, but spinal deformations are rarely seen. We report a very rare association of multiple spinal malformations, right kidney absence, and pelvic Wilms tumor in a 21-month-old girl. The report includes a brief review of relevant literature.

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.

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.

[Dumbbell nephroblastoma: an uncommon cause of spinal cord compression]

Rarely children with Wilms' tumor develop spinal cord dysfunction by metastatic spread into the epidural space or the cord parenchyma. In the case reported here, the mechanism of spinal compression was different.

CASE REPORT

The authors report the clinical course of a 2-month-old boy with retroperitoneal extrarenal Wilms' tumor below the left kidney, characterized with a spinal cord compression developed through the intervertebral foramina.

CONCLUSION

Abdominal tumor, usually corresponding to neuroblastoma, may be a nephroblastoma.

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.

Perirenal mass of Langerhans cell histiocytosis

A 15-month-old girl with Langerhans cell histiocytosis (LCH), Letterer-Siwe disease, was referred to our hospital in 1984. Whilst on treatment with cytotoxic drugs, a perirenal mass was detected and hydronephrosis became evident when she was 29 months old. Percutaneous nephrostomy tubes were placed in the pelvis, bilaterally and replaced every 6 months. The mass was not completely controlled and chronic pyelonephritis continued. Biopsy of the mass convoluted kidney hilus revealed histiocytic invasion. Although multiple organ systems are involved in LCH and abdominal malignant tumours may be accompanied by hydronephrosis, to our knowledge, this is the first case report of abdominal LCH and the ensuing hydronephrosis. Percutaneous nephrostomy tubes proved useful, but more convenient, less painful and infection-limited approaches need to be designed.