F-18 FDG PET/CT imaging of metastatic extrarenal Wilms tumor arising in the inguinal canal

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.

18Fluorine-fluorodeoxyglucose PET-CT findings in a case of rarely seen metastatic adult extrarenal Wilms' tumor of retroperitoneum presenting as lower limb edema

Wilms’ tumor also called as nephroblastoma is commonly seen extracranial solid tumor involving kidneys in children. Rarely, Wilms’ tumor can arise from ectopic nephrogenic remnants located outside the kidneys. Extrarenal Wilms’ tumor comprises 3% of total Wilms’ tumor with its incidence even less common in adults. We report the staging and restaging fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of locally advanced metastatic extrarenal adult Wilms’ tumor involving the retroperitoneum.

FDG PET/CT Findings of Extrarenal Wilms Tumor Originating From the Spinal Cord

Extrarenal Wilms tumor (ERWT) is an extremely rare neoplasm of childhood. It occurs predominantly in retroperitoneum and pelvic or inguinal region without involvement of the kidneys. Although the importance of FDG PET/CT in Wilms tumor is well known, its use in ERWT is limited. Herein, we present FDG PET/CT findings of a 3-year-old girl with a lumbar mass, which was later diagnosed with ERWT.

Energy metabolism in neuroblastoma and Wilms tumor

To support high proliferation, the majority of cancer cells undergo fundamental metabolic changes such as increasing their glucose uptake and shifting to glycolysis for ATP production at the expense of far more efficient mitochondrial energy production by oxidative phosphorylation (OXPHOS), which at first glance is a paradox. This phenomenon is known as the Warburg effect. However, enhanced glycolysis is necessary to provide building blocks for anabolic growth. Apart from the generation of ATP, intermediates of glycolysis serve as precursors for a variety of biosynthetic pathways essential for cell proliferation. In the last 10-15 years the field of tumor metabolism has experienced an enormous boom in interest. It is now well established that tumor suppressor genes and oncogenes often play a central role in the regulation of cellular metabolism. Therefore, they significantly contribute to the manifestation of the Warburg effect. While much attention has focused on adult solid tumors, so far there has been comparatively little effort directed at elucidation of the mechanism responsible for the Warburg effect in childhood cancers. In this review we focus on metabolic pathways in neuroblastoma (NB) and Wilms tumor (WT), the two most frequent solid tumors in children. Both tumor types show alterations of the OXPHOS system and glycolytic features. Chromosomal alterations and activation of oncogenes like MYC or inactivation of tumor suppressor genes like TP53 can in part explain the changes of energy metabolism in these cancers. The strict dependence of cancer cells on glucose metabolism is a fairly common feature among otherwise biologically diverse types of cancer. Therefore, inhibition of glycolysis or starvation of cancer cells through glucose deprivation via a high-fat low-carbohydrate diet may be a promising avenue for future adjuvant therapeutic strategies.