Current standards of care in bladder and prostate rhabdomyosarcoma

Small cell neuroendocrine carcinoma and poorly differentiated rhabdomyosarcomas of the urinary bladder in adults-A comparative analysis in favor of a common histogenesis

Rhabdomyosarcoma (RMS) of the urinary bladder in adults and elderly is an exceptionally rare neoplasm that displays poorly differentiated solid (alveolar-like) small cell pattern, frequently indistinguishable from small cell neuroendocrine carcinoma (SCNEC). However, the histogenesis of RMS and SCNEC and their inter-relationship have not been well studied and remained controversial. We herein analyzed 23 SCNEC and 3 small round cell RMS of the bladder for neuroendocrine (synaptophysin + chromogranin A) and myogenic (desmin + myogenin) marker expression and for TERT promoter mutations. In addition, the RMS cohort and one SCNEC that was revised to RMS were tested for gene fusions using targeted RNA sequencing (TruSight Illumina Panel which includes FOXO1 and most of RMS-related other genes). Overall, significant expression of myogenin and desmin was observed in one of 23 original SCNEC justifying a revised diagnosis to RMS. On the other hand, diffuse expression of synaptophysin was noted in 2 of the 4 RMS, but chromogranin A was not expressed in 3 RMS tested. TERT promoter mutations were detected in 15 of 22 (68%) SCNEC and in two of three (67%) assessable RMS cases, respectively. None of the four RMS cases had gene fusions. Our data highlights phenotypic and genetic overlap between SCNEC and RMS of the urinary bladder. High frequency of TERT promoter mutations in SCNEC is in line with their presumable urothelial origin. In addition, the presence of TERT promoter mutation in 2 of 3 RMS and lack of FOXO1 and other gene fusions in all 4 RMSs suggest a mucosal (urothelial) origin, probably representing extensive monomorphic rhabdomyoblastic transdifferentiation in SCNEC.

18 F-FDG PET/CT of Alveolar Rhabdomyosarcoma of Prostate in a 17-Year-Old Boy

ABSTRACT

Rhabdomyosarcoma of the prostate is a rare malignancy that usually presents in childhood and adolescence with symptoms of bladder outlet obstruction. Serum prostate-specific antigen is usually normal, and 18 F-FDG PET/CT has a crucial role to rule out distant metastases. We present a case of alveolar rhabdomyosarcoma of the prostate in a 17-year-old boy.

Urinary Bladder Masses, Rare Subtypes, and Masslike Lesions: Radiologic-Pathologic Correlation

Urinary bladder masses are commonly encountered in clinical practice, with 95% arising from the epithelial layer and rarer tumors arising from the lamina propria, muscularis propria, serosa, and adventitia. The extent of neoplastic invasion into these bladder layers is assessed with multimodality imaging, and the MRI-based Vesical Imaging Reporting and Data System is increasingly used to aid tumor staging. Given the multiple layers and cell lineages, a diverse array of pathologic entities can arise from the urinary bladder, and distinguishing among benign, malignant, and nonneoplastic entities is not reliably feasible in most cases. Pathologic assessment remains the standard of care for classification of bladder masses. Although urothelial carcinoma accounts for most urinary bladder malignancies in the United States, several histopathologic entities exist, including squamous cell carcinoma, adenocarcinoma, melanoma, and neuroendocrine tumors. Furthermore, there are variant histopathologic subtypes of urothelial carcinoma (eg, the plasmacytoid variant), which are often aggressive. Atypical benign bladder masses are diverse and can have inflammatory or iatrogenic causes and mimic malignancy. ^© RSNA, 2022 Online supplemental material is available for this article.

Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and represents a high-grade neoplasm of skeletal myoblast-like cells. Decades of clinical and basic research have gradually improved our understanding of the pathophysiology of RMS and helped to optimize clinical care. The two major subtypes of RMS, originally characterized on the basis of light microscopic features, are driven by fundamentally different molecular mechanisms and pose distinct clinical challenges. Curative therapy depends on control of the primary tumour, which can arise at many distinct anatomical sites, as well as controlling disseminated disease that is known or assumed to be present in every case. Sophisticated risk stratification for children with RMS incorporates various clinical, pathological and molecular features, and that information is used to guide the application of multifaceted therapy. Such therapy has historically included cytotoxic chemotherapy as well as surgery, ionizing radiation or both. This Primer describes our current understanding of RMS epidemiology, disease susceptibility factors, disease mechanisms and elements of clinical care, including diagnostics, risk-based care of newly diagnosed and relapsed disease and the prevention and management of late effects in survivors. We also outline potential opportunities to further translate new biological insights into improved clinical outcomes.

Tissue Compatibility of SN-38-Loaded Anticancer Nanofiber Matrices

Delivery of chemotherapy in the surgical bed has shown preclinical activity to control cancer progression upon subtotal resection of pediatric solid tumors, but whether this new treatment is safe for tumor-adjacent healthy tissues remains unknown. Here, Wistar rats are used to study the anatomic and functional impact of electrospun nanofiber matrices eluting SN-38-a potent chemotherapeutic agent-on several body sites where pediatric tumors such as neuroblastoma, Ewing sarcoma, and rhabdomyosarcoma arise. Blank and SN-38-loaded matrices embracing the femoral neurovascular bundle or in direct contact with abdominal viscera (liver, kidney, urinary bladder, intestine, and uterus) are placed. Foreign body tissue reaction to the implants is observed though no histologic damage in any tissue/organ. Skin healing is normal. Tissue reaction is similar for SN-38-loaded and blank matrices, with the exception of the hepatic capsule that is thicker for the former although within the limits consistent with mild foreign body reaction. Tissue and organ function is completely conserved after local treatments, as assessed by the rotarod test (forelimb function), hematologic tests (liver and renal function), and control of clinical signs. Overall, these findings support the clinical translation of SN-38-loaded nanofiber matrices to improve local control strategies of surgically resected tumors.

Urothelial carcinoma in children: A case series

OBJECTIVE

To report a series of 5 patients with urothelial bladder cancer (UBC) three of them with a history of exposure to amines and only two with gross hematuria.

MATERIALS AND METHODS

After obtaining ethical and legal authorization, we performed a restrospective monocentric study. We collected information of patients with UBC over a period of 10 years. We recorded: age, sex, reason for presentation, familial history and risk factors, preoperative assessment, surgical details, histological type and grade, follow-up.

RESULTS

2 children came to our attention for hematuria and 3 for incidental bladder mass finding, at a median age of 11.8 years. We performed microscopically complete transurethral resection of the tumor (TURB). Median tumor size was 1.8cm. No further therapy was required. All cancers belonged to NMIBC (Non-muscle-invasive Bladder Cancer) considering the 2004 WHO classification: 2 urothelial papillomas, 2 papillary tumors with low grade malignancy (PUN-LPM) and 1 papillary urothelial carcinoma of low histological grade (LG-PUC Ta, N0, M0). There was not any complications and no relapse occurred during follow-up (median 30 months).

CONCLUSIONS

In this study, UBCs presenting at a young age were low-grade and have not recurred in follow-up. This confirms the results of other series reported in Literature. Therefore there might be the space to perform a follow-up dedicated to children.

Pediatric Robotic Prostatectomy and Pelvic Lymphadenectomy for Embryonal Rhabdomyosarcoma

We present the first published case of a pediatric robot-assisted prostatectomy and pelvic lymphadenectomy for refractory prostatic embryonal rhabdomyosarcoma. The patient is a 7-year-old male who had been treated with 3 cycles of chemotherapy and radiation, who underwent prostatectomy and lymphadenectomy for a recurrent mass. Surgery was uncomplicated and yielded negative surgical margins. We highlight the surgical technique and feasibility of utilizing robotic surgery for pediatric prostatectomy.

When Chemotherapy Is Not Enough-Management of Prostatic Embryonal Rhabdomyosarcoma in an Infant

A baby boy was diagnosed with embryonal rhabdomyosarcoma causing left hydroureteronephrosis. A loop ureterostomy was performed, and the infant was treated per the RMS13 protocol. After 3 months of chemotherapy, the infant's tumor burden increased, and he underwent radical cystoprostatectomy and right-to-left transureteroureterostomy (end-to-end fashion utilizing the distal limb of his ureterostomy). This innovative method was utilized because the infant's tumor burden was too large to be treated effectively and safely with radiation. One year later, the infant has no evidence of disease. This demonstrates that optimal management of rhabdomyosarcoma is still unknown; therefore, each child warrants an individualized approach for optimal outcomes.