A Pediatric Case of Embryonal Rhabdomyosarcoma of the Bladder: A Case Report and Literature Review

Rhabdomyosarcomas (RMS) are malignant tumors derived embryonically from the mesenchymal tissue that form from the skeletal muscles. It is the most common soft tissue sarcoma in pediatrics. The embryonal mesenchymal subtype is the most common and is often diagnosed in the first decade of life. Treatment of RMS is multimodal including systemic chemotherapy, surgery and radiotherapy. In sub-Saharan Africa, data in pediatric cancers, and on RMS in particular, are rare and limited generaly to case reports. This case aims to report a bladder embryonal rhabdomyosarcoma in a 19-month-old child boy who is diagnosed post mortem. It was referred to the pediatric emergency department for sudden painful complete inability to urinate. On clinical examination, an acute urine retention was diagnosed and transurethral catherisation was established with resultant drainnage of hematic urine. Hemodynamic parameters were unstable, with oxygen saturation at 91%. A painless well-fixed mass of solid appearance was palpable at the hypogastric. Laboratory exams showed an impaired renal function with metabolic acidosis. Urine culture and sensitivity testing revealed a urinary tract infection that isolated klebsiella pneumonia. Emergency ultrasonography of the urinary tract, showed a large, heterogeneous, multilobulated intravesical vegetative mass measuring 60.85 x 35.34 x 42.2mm, responsible of a bilateral stage VI ureterohydronephrosis. Abdominal-pelvic MRI showed a vegetative postero-basal tissue mass invading the entire bladder trigone and classified T3bN0Mx. Bilateral nephrostomy was performed the following day with a medical resuscitation, and antibiotherapy adapted to renal function, was installed. A cystoscopy was performed under general anaesthesia showed a large bladder mass filling almost the entire bladder lumen. The biopsy was done using a monopolar resector. The post-operative event was marked by a cardiorespiratory arrest with failure of all reanimation maneuvers occurred. The histological results the biopsy showed a sarcomatous proliferation of small round or spindle-shaped fusiformed cells with hyperchromatic nuclei and little cytoplasm. Mitotic activity was high. Immunohistochemical analysis showed desmin and myoginin, confirming the diagnosis of embryonal-type rhabdomyosarcoma classified as TNM stage II and ISRG IV.