Urothelial carcinoma of the bladder in a pediatric patient

Abstract

Urothelial carcinoma of the bladder in children and adolescents is rare. The World Health Organization database has recorded approximately 80 patients under age 16 that have been diagnosed with papillary bladder tumour since 1968. 1 We are reporting on our case of urothelial carcinoma diagnosed in a 14-year-old male who presented with painless gross hematuria. Case reportOur patient is a 14-year-old South Asian male, who immigrated to Canada from the Philippines in 2012. He had an isolated episode of painless, gross hematuria in July 2015, after which he presented to his primary care physician and renal and bladder ultrasound was ordered. Referral was also made to urology at that time.The patient's medical history was significant for a remote history of pulmonary tuberculosis for which he received treatment, as well as a history of an intestinal parasite. The remainder of the history was non-contributory for typical risk factors of urothelial carcinoma, including no history of chemotherapy, radiation, or chemical exposure. He and his family denied history of tobacco usage and there was no family history of genitourinary malignancy.Physical examination revealed a normal abdominal and genitourinary examination.Ultrasound revealed an irregular lobulated polypoid lesion on the right postero-lateral bladder wall measuring 26 x 29x 17 mm (Fig. 1). The kidneys were unremarkable.The patient was taken to the operating room for a cystoscopy and transurethral resection of bladder tumour. Cystoscopy revealed a papillary lesion on the right posterolateral bladder wall just distal to the ureteric orifice, consistent with what was seen on imaging. Due to the patient's post-pubertal stage of genital development, the pediatric resectoscope could not reach the tumour. We gently dilated his urethra with sounds and used the 26 F resectoscope for resection. The tumour was completely resected and a sample was taken at the base.Pathology revealed a low-grade papillary urothelial neoplasm with no definite invasion into the muscularis mucosae. Also reported was a large inverted component, the presence of small nests of urothelial cells in the stalk, and the strong staining for CK5 and CD44. Final pathology read papillary low-grade urothelial carcinoma without invasion (Ta). DiscussionThough uncommon, there have been several consistent findings in regards to papillary bladder tumour occurrence in children. Tumours are predominately low-grade, more common in males at a 3:1 ratio, more common in White compared to Black patients, and are most often located on the trigone.2 They also seem to have a lower rate of recurrence than similarly staged tumours in the adult population, possibly due to field change being a less likely etiology in the absence of carcinogen exposure.3 As in our case, painless gross hematuria is the presenting symptom in >90% of cases. There are no specific risk factors in the small number of cases reported. Associations reported in children include passive smoking, exposure to cyclophosphamide or muscle relaxant...