Bladder and Testis Oncology

Rhabdomyosarcoma (RMS)

• Epidemiology
  • Most common soft-tissue sarcoma in children
• Genetics
  • Most cases are considered to be sporadic
  • Genetic syndromes associated with RMS:
    • Li-Fraumeni syndrome
    • Neurofibromatosis
    • Basal cell nevus syndrome
    • Costello syndrome
    • Noonan syndrome
    • Multiple endocrine neoplasia type 2A
• Pathology and molecular biology
  • Histologic categories (3):
    1. Embryonal
       • Most common form of bladder or prostate RMS.
    2. Alveolar
       • Uncommon in the bladder or prostate
       • Two distinct types, PAX-FOXO1 fusion positive and negative, and fusion-positive tumors carry a worse prognosis
    3. Undifferentiated
• Management
  • Radical surgery may be required if there is lack of response to non-operative treatment.
• Prognosis
  • Prognostic factors
    • Site of origin
      • Prostate has the worst prognosis
      • Vaginal has best prognosis
    • Histology
      • Embryonal histology associated with improved prognosis compared to alveolar

Urothelial carcinoma of the Bladder

• Uncommon
• Lesions are unifocal, typically low grade and not prone to recurrence
• Management
  • Treatment consisting of resection only is adequate. Adjuvant treatment is not given.
  • Surveillance cystoscopy is not needed; ultrasound is remarkably accurate and is an adequate surveillance strategy

Testicular Tumors

• More likely benign in pre-pubertal males (in contrast to post-pubertal males where most testicular tumours are malignant)
• Epidemiology
  • The most common pathologic diagnosis in children with a testicular mass is a YST, followed by teratoma
• Germ Cell Tumors
  • Pathology
    • Tertatoma
      • According to some series, teratomas are the most common testicular tumor in children and consist of variable combinations of the three primitive embryologic germ cell layers [contradicts above]
      • Consist of variable combinations of the three primitive embryologic germ cell layers
      • Do not express AFP
      • In contrast to teratoms in post-pubertal males, most teratomoas in pre-pubertal male are benign, consisting of mature elements only, and do not metastasize
      • Preferred treatment for suspected teratoma is partial orchiectomy
    • Epidermoid cysts
      • Benign lesion; represent a monolayer teratoma
      • May account for >15% of prepubertal testis lesions
      • Do not express AFP
      • Preferred treatment for suspected epidermoid cysts is partial orchiectomy
      • No surveillance is required after treatment
    • Yolk-sac tumour (YST)
      • Pathology
        • Schiller-Duval bodies consist of a central blood vessel surrounded by two layers of tumor cells
          • Pathognomonic for YSTs.
      • AFP levels are elevated  
      • When metastases occur, YSTs often exhibit hematogenous spread to the lungs, without retroperitoneal disease. For these reasons retroperitoneal lymph node dissection (RPLND) plays very little role in pre-pubertal YST.
        • RPLND is used exclusively for patients with a residual retroperitoneal mass or persistently elevated AFP after chemotherapy and orchiectomy
  • Presentation, Evaluation, and Staging
    • See CW11 Figure 156-7
    • Ultrasonography
      • Teratomas
        • Heterogeneous complex lesions and may contain cystic and solid components.
        • Bony elements appear as calcifications with shadowing.
        • Adipose tissue appears as echogenic areas without shadowing.
      • Epidermoid cysts
        • Characteristic appearance described as “onion skin” comprised of concentric rings of alternating hypoechoic and hyperechoic lesions.
      • YSTs
        • Typically well circumscribed and heterogeneous in appearance.
        • May appear hypervascular and may have areas of hemorrhage and necrosis.
      • Sertoli and Leydig cell tumors
        • Similar in appearance
        • Commonly manifest as a well-circumscribed hypoechoic mass.
    • Labs
      • Tumour markers
        • Interpretation of AFP levels in infants undergoing evaluation for a testis mass must be performed with caution as a result of the physiologically persistent elevation of AFP in infants age < 1
• Tumors Associated with Disorders of Sexual Differentiation
  • See Disorders of Sexual Differentiation Chapter Notes
  • Patients with dysgenetic testis or hypovirulization have an increased incidence of testicular tumors
• Gonadal Stromal Tumors
  • Juvenile granulosa cell tumors
    • Most common testicular tumors affecting neonates
  • Leydig cell tumors
    • Hormonally active; associated with precocious puberty.
  • Sertoli cell
    • Usual presentation is a painless mass
    • Associated with endocrinologic and genetic syndromes such as Peutz-Jeghers and Carney syndromes
    • 10% are hormonally active
• Leukemia and Lymphoma
  • The most common cancers with metastases to the testis are leukemia and lymphoma

Paratesticular Rhabdomyosarcoma

• Arises from the testicular tunicae, epididymis, or spermatic cord.
• Up to 40% of paratesticular lesions are due to RMS
• Management
  • Multimodal involving surgery and chemotherapy with vincristine, dactinomycin, and cyclophosphamide
  • Children age > 10 should undergo a staging ipsilateral retroperitoneal lymph node dissection, and not observation, because of a high occurrence of retroperitoneal failure

References

• Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, vol 4, chap 156